Chlorogenic acid ameliorates heart failure by attenuating cardiomyocyte ferroptosis

Objective:To elucidate the effects of chlorogenic acid(CGA),a bioactive polyphenol compound prevalent in traditional Chinese medicine and various foods,including Lonicera japonica Thunb.(Jin Yin Hua),Eucommia ulmoides Oliv.(Du Zhong Ye),tea,and coffee,on cardiomyocyte ferroptosis and heart failure.Methods: We assessed the effect of CGA on cardiac function using a mouse model of heart failure induced by transverse aortic constriction(TAC).These indicators included the left ventricular ejection fraction(LVEF),fractional shortening(LVFS),end-systolic volume(LVESV),end-diastolic volume(LVEDV),end-systolic diameter(LVESD),and end-diastolic diameter(LVEDD).An isoprenaline hydrochloride(ISO)-induced H9c2 cardiomyocyte cell model was also established,and the cells were treated with various concentrations of CGA.To assess the effect of CGA on ferroptosis in cardiomyocytes,we measured cell viability and evaluated the levels of intracellular reactive oxygen species(ROS),ferrous ions(Fe^(2+)),and lipid peroxidation using fluorescent staining.To clarify the ferroptosis signaling pathway regulated by CGA,western blotting was used to examine the expression of ferroptosis biomarkers,specifically solute carrier family 7 member 11(SLC7A11)and glutathione peroxidase 4(GPX4),in H9c2 cardiomyocytes and mouse myocardial tissues.Results: CGA significantly enhanced cardiac performance indices such as LVEF,LVFS,LVESV,LVEDV,LVESD,and LVEDD.H9c2 cardiomyocytes exposed to ISO showed decreased cell viability and increased ROS levels,Fe^(2+)content,and lipid peroxidation levels.However,CGA treatment significantly ameliorated these changes.Additionally,in both H9c2 cardiomyocytes and myocardial tissue obtained from mice with TAC,CGA increased the expression of ferroptosis-related proteins,including SLC7A11 and GPX4.Conclusion: CGA has the potential to enhance cardiac function and diminish lipid peroxidation and ROS levels in cardiomyocytes via the SLC7A11/GPX4 signaling pathway.This process alleviates ferroptosis in cardiomyocytes.These results provide new insights into the clinical use of CGA and the management of heart failure.

Atherosclerosis originating from childhood:Specific features

Atherosclerosis is extremely widespread.Traditionally,it is considered a disease of older people,who most often experience problems with the heart and blood vessels.While much attention from the scientific community has been paid to studying the association between aging and atherosclerosis,as well as its consequences,there is evidence that atherosclerosis occurs at an early age.Atherosclerosis may form both during intrauterine development and in childhood.Nutrition plays an important role in childhood atherosclerosis,along with previous infectious diseases and excess weight of both the child and the mother.In the present review,we examined the development of atherosclerosis and the prerequisites in childhood.

反相高效液相色谱法(邻苯二甲醛柱前衍生)同时测定血清胸腺因子和胸腺素α_1

体内外实验研究均已证明血清胸腺因子(FTS)和胸腺素α_1(THY)是促进淋巴细胞分化并增强其功能的重要因子。它们在血清中水平变化受某些生物因素和疾病的影响,诸如肿瘤、免疫缺陷或衰老等均可导致FTS、THY水平下降;此外胸腺激素在临床中的应用也很普遍,因此血清及其它体液中FTS、THY的定量分析对研究免疫系统疾病具有重要价值。 由于目前胸腺肽的生物学检测方法受体液中某些抑制因子的影响,为此我们利用邻苯二甲醛(OPA)与寡肽中ε-甘氨酸残基反应衍生较强荧光的原理,使用OPA柱前衍生法对FTS、THY测定条件进行了研究,并对血清中FTS、THY的提取及测定作了初步探讨,表明本法对体液中游离的FTS。

Laboratory markers in ulcerative colitis: Current insights and future advances

Ulcerative colitis(UC)and Crohn’s disease(CD)are the major forms of inflammatory bowel diseases(IBD)in man.Despite some common features,these forms can be distinguished by different genetic predisposition,risk factors and clinical,endoscopic and histological characteristics.The aetiology of both CD and UC remains unknown,but several evidences suggest that CD and perhaps UC are due to an excessive immuneresponse directed against normal constituents of the intestinal bacterial flora.Tests sometimes invasive are routine for the diagnosis and care of patients with IBD.Diagnosis of UC is based on clinical symptoms combined with radiological and endoscopic investigations.The employment of non-invasive biomarkers is needed.These biomarkers have the potential to avoid invasive diagnostic tests that may result in discomfort and potential complications.The ability to determine the type,severity,prognosis and response to therapy of UC,using biomarkers has long been a goal of clinical researchers.We describe the biomarkers assessed in UC,with special reference to acute-phase proteins and serologic markers and thereafter,we describe the new biological markers and the biological markers could be developed in the future:(1)serum markers of acute phase response:The laboratory tests most used to measure the acute-phase proteins in clinical practice are the serum concentration of C-reactive protein and the erythrocyte sedimentation rate.Other biomarkers of inflammation in UC include platelet count,leukocyte count,and serum albumin and serum orosomucoid concentrations;(2)serologic markers/antibodies:In the last decades serological and immunologic biomarkers have been studied extensively in immunology and have been used in clinical practice to detect specific pathologies.In UC,the presence of these antibodies can aid as surrogate markers for the aberrant host immune response;and(3)future biomarkers:The development of biomarkers in UC will be very important in the future.The progress of molecular biology tools(microarrays,proteomics and nanotechnology)have revolutionised the field of the biomarker discovery.The advances in bioinformatics coupled with cross-disciplinary collaborations have greatly enhanced our ability to retrieve,characterize and analyse large amounts of data generated by the technological advances.The techniques available for biomarkers development are genomics(single nucleotide polymorphism genotyping,pharmacogenetics and gene expression analyses)and proteomics.In the future,the additionof new serological markers will add significant benefit.Correlating serologic markers with genotypes and clinical phenotypes should enhance our understanding of pathophysiology of UC.

Mitochondrial dysfunction and mitochondrial DNA mutations in atherosclerotic complications in diabetes

Mitochondrial DNA(mtDNA) is particularly prone to oxidation due to the lack of histones and a deficient mismatch repair system.This explains an increased mutation rate of mtDNA that results in heteroplasmy,e.g.,the coexistence of the mutant and wild-type mtDNA molecules within the same mitochondrion.In diabetes mellitus,glycotoxicity,advanced oxidative stress,collagen cross-linking,and accumulation of lipid peroxides in foam macrophage cells and arterial wall cells may significantly decrease the mutation threshold required for mitochondrial dysfunction,which in turn further contributes to the oxidative damage of the diabetic vascular wall,endothelial dysfunc-tion,and atherosclerosis.

pregnane X receptor and constitutive androstane receptor modulate differently CYp3A-mediated metabolism in earlyand late-stage cholestasis

AIM To ascertain whether cholestasis affects the expression of two CYP3 A isoforms(CYP3 A1 and CYP3 A2) and of pregnane X receptor(PXR) and constitutive androstane receptor(CAR).METHODS Cholestasis was induced by bile duct ligation in 16 male Wistar rats; whereas 8 sham-operated rats were used as controls. Severity of cholestasis was assessed on histological examination of liver sections, and serum concentrations of albumin, AST, ALT, GGT, ALPK and bilirubin. Gene and protein expressions of PXR, CAR, CYP3 A1 and CYP3 A2 were assessed by means of q RT-PCR and Western blot, respectively. Alterations in CYP3 A activity were measured by calculating the kinetic parameters of 4-OH and 1'-OH-midazolam hydroxylation, marker reactions for CYP3 A enzymes.RESULTS The m RNA and protein expression of CYP3 A1 increased significantly in mild cholestasis(P < 0.01). At variance, m RNA and protein expression of CYP3 A2 didn't change in mild cholestasis, whereas the expression and activity of both CYP3 A1 and CYP3 A2 decreased dramatically when cholestasis became severe. Consistently with these observations, the nuclear expression of both PXR and CAR, which was measured because they both translocate into the cell nucleus after their activation, virtually disappeared in the late stage of cholestatic injury, after an initial increase. These results indicate that early-and late-stage cholestasis affects CYP3 Amediated drug metabolism differently, probably as consequence of the different activation of PXR and CAR.CONCLUSION Early-and late-stage cholestasis affects CYP3 Amediated drug metabolism differently. PXR and CAR might be targeted therapeutically to promote CYP3 Amediated liver detoxification.

Epidemiological transition of colorectal cancer in developing countries: Environmental factors, molecular pathways, and opportunities for prevention

Colorectal cancer(CRC)is one of the leading causes of cancer and cancer-related mortality worldwide.The disease has been traditionally a major health problem in industrial countries,however the CRC rates are increasing in the developing countries that are undergoing economic growth.Several environmental risk factors,mainly changes in diet and life style,have been suggested to underlie the rise of CRC in these populations.Diet and lifestyle impinge on nuclear receptors,on the intestinal microbiota and on crucial molecular pathways that are implicated in intestinal carcinogenesis.In this respect,the epidemiological transition in several regions of the world offers a unique opportunity to better understand CRC carcinogenesis by studying the disease phenotypes and their environmental and molecular associations in different populations.The data from these studies may have important implications for the global prevention and treatment of CRC.

Inorganic phosphate in the development and treatment of cancer:A Janus Bifrons?

Inorganic phosphate(Pi) is an essential nutrient to living organisms. It is required as a component of the energy metabolism,kinase/phosphatase signaling and in the formation and function of lipids,carbohydrates and nucleic acids and,at systemic level,it plays a key role for normal skeletal and dentin mineralization. Pi represents an abundant dietary element and its intestinal absorption is efficient,minimally regulated and typically extends to approximately 70%. Maintenance of proper Pi homeostasis is a critical event and serum Pi level is maintained within a narrow range through an elaborate network of humoral interactions and feedback loops involving intestine,kidney,parathyroid gland and bone,and depends on the activity of a number of hormones,including parathyroid hormone,1,25-dihydroxy vitamin D,and fibroblast growth factor 23 as major regulators of Pi homeostasis. Notably,Pi intake seemingly continues to increase as a consequence of chronic high-phosphorus(P) diets deriving from the growing consumption of highly processed foods,especially restaurant meals,fast foods,and convenience foods. Several recent reports have generated significant associations between high-P intake or high-serum Pi concentration and morbidity and mortality. Many chronic diseases,including cardiovascular diseases,obesity and even cancer have been proposed to be associated with high-P intakes and high-serum Pi concentrations. On the other hand,there is also evidence that Pi can have antiproliferative effects on some cancer cell types,depending on cell status and genetic background and achieve additive cytotoxic effects when combined with doxorubicin,illustrating its potential for clinical applications and suggesting that up-regulating Pi levels at local sites for brief times,might contribute to the development of novel and cheap modalities for therapeutic intervention in some tumours. Overall,the influence of Pi on cell function and the possible relationship to cancer have to be fully understood and investigated further.

Association of the level of heteroplasmy of the 15059G>A mutation in the MT-CYB mitochondrial gene with essential hypertension

AIM: To examine whether the heteroplasmy level for 15059G】A mutation in the mitochondrial genome might be associated with essential hypertension. METHODS: This cross-sectional study involved 196 unrelated participants randomly selected from general population (90 males and 106 females) who underwent a regular medical check-up at the Institute for Ath-erosclerosis Research (Moscow, Russia). One hundred and twenty of them (61%) had essential hypertension, and 76 (39%) were apparently healthy normotensive persons. The level of heteroplasmy for 15059G】A mutation occurring in the coding region of cytochrome b gene (MT-CYB) of mtDNA isolated from the blood leukocytes, was quantified using DNA pyrosequencing method. RESULTS: The 15059G】A heteroplasmy level ranged between 4% and 83%, with a median level of 31%. Between the upper and lower quartiles of 15059G】A heteroplasmy distribution, significant differences were observed for patients’ age, systolic blood pressure, and triglyceride levels. 15059G】A heteroplasmy correlated both with age (r = 0.331, P 【 0.001) and the presence of hypertension (r = 0.228, P = 0.002). Regression analysis revealed that the age explains 12% variability of 15059G】A heteroplasmy, and hypertension independently explains more 5% variability. The 15059G】A heteroplasmy exceeding 31% was found to be significantly associated with a higher risk of essential hypertension (odds ratio 2.76; P (Fisher) 0.019]. The study participants with high 15059G】A heteroplasmy level were found to have significantly higher age (P 【 0.001) and the prevalence of essential hypertension (P = 0.033), as compared to those with low 15059G】A heteroplasmy level. These observations suggested a positive correlation between the level of 15059G】A heteroplasmy and essential hypertension. CONCLUSION: This study provides the evidence of association of mtDNA 15059G】A mutation heteroplasmy with essential hypertension.

Cytokinome profile evaluation in patients with hepatitis C virus infection

The &#x02018;&#x02018;omics sciences&#x02019;&#x02019; (genomics, transcriptomics, proteomics) are often used to study living organisms as a whole system by evaluating the complex expression patterns of genes, miRNA, proteins, and metabolites. This study aimed, through bioinformatics and systems biology, to decipher the cytokinome profile in the evolution of inflammatory processes leading to cancer. The cytokinome was defined as the totality of cytokines and their interactions in and around biological cells. The system biology approach would provide a better understanding of the complex interaction network of cytokines, especially in cancer patients. Acquired knowledge would enable health providers with tools to evaluate disease onset through progression as well as identifying innovative therapeutic strategies. Understanding the role each cytokine plays in the metabolic network is of great importance. This paper reviews our group&#x02019;s &#x02018;&#x02018;omics&#x02019;&#x02019; work. In particular, it addresses the role cytokines play in liver disease in six different scenarios. The first is the role the cytokines play in chronic inflammatory diseases and cancers. The second is the significance of the cytokinome profile. The third is the role of liver cirrhosis as an inflammatory disease. The fourth is the comparison of cytokine levels evaluated in patients with chronic hepatitis C virus (HCV) or with HCV-related cirrhosis. The fifth is the comparison of cytokine levels evaluated in patients with HCV-related cirrhosis in the presence and absence of type 2 diabetes. And lastly, we present a comparison of cytokine levels evaluated in patients with HCV-related cirrhosis in the presence and absence of hepatocellular carcinoma.

Cystic fibrosis transmembrane conductance regulator functional evaluations in a G542X+/-IVS8Tn:T7/9 patient with acute recurrent pancreatitis

BACKGROUND Acute recurrent pancreatitis(ARP)is characterized by episodes of acute pancreatitis in an otherwise normal gland.When no cause of ARP is identifiable,the diagnosis of"idiopathic"ARP is given.Mutations in the cystic fibrosis transmembrane conductance regulator(CFTR)gene increase the risk of ARP by 3-to 4-times compared to the general population,while cystic fibrosis(CF)patients present with a 40-to 80-times higher risk of developing pancreatitis.CASE SUMMARY In non-classical CF or CFTR-related disorders,CFTR functional tests can help to ensure a proper diagnosis.We applied an individualized combination of standardized and new CFTR functional bioassays for a patient referred to the Verona CF Center for evaluation after several episodes of acute pancreatitis.The CFTR genotype was G542X+/-with IVS8Tn:T7/9 polymorphism.The sweat(Cl-)values were borderline.Intestinal current measurements were performed according to the European Cystic Fibrosis Society Standardized Operating Procedure.Recent nasal surgery for deviated septum did not allow for nasal potential difference measurements.Lung function and sputum cultures were normal;azoospermia was excluded.Pancreas divisum was excluded by imaging but hypoplasia of the left hepatic lobe was detected.Innovative tests applied in this case include sweat rate measurement by image analysis,CFTR function in monocytes evaluated using a membrane potential-sensitive fluorescent probe,and the intestinal organoids forskolin-induced swelling assay.CONCLUSION Combination of innovative CFTR functional assays might support a controversial diagnosis when CFTR-related disorders and/or non-classical CF are suspected.

Intimal pericytes as the second line of immune defence in atherosclerosis

Inflammation plays an essential role in the development of atherosclerosis. The initiation and growth of atherosclerotic plaques is accompanied by recruitment of inflammatory and precursor cells from the bloodstream and their differentiation towards pro-inflammatory phenotypes. This process is orchestrated by the production of a number of pro-inflammatory cytokines and chemokines. Human arterial intima consists of structurally distinct leaflets, with a proteoglycan-rich layer lying immediately below the endothelial lining. Recent studies reveal the important role of stellate pericyte-like cells(intimal pericytes) populating the proteoglycan-rich layer in the development of atherosclerosis. During the pathologic process, intimal pericytes may participate in the recruitment of inflammatory cells by producing signalling molecules and play a role in the antigen presentation. Intimal pericytes are also involved in lipid accumulation and the formation of foam cells. This review focuses on the role of pericytelike cells in the development of atherosclerotic lesions.

Neonatal Exposure to the Dipeptidyl Peptidase-IV Inhibitors Diprotin A and Sitagliptin Induces Depression-Like Behavior, Anxiety, and Latent Aggression in Adolescent and Adult Rats

Emotional and motivational disorders in adults are often considered to be the result of altered neurodevelopment. Clinical and experimental data provide evidence that serine protease dipeptidyl peptidase-IV (DPP-IV, EC 3.4.14.5) is involved in the pathophysiology of psycho-emotional disorders. Recently, we have shown that adolescent and adult rats exhibit an increase in anxiety and depression-related behaviors after neonatal administration of a synthetic non-competitive inhibitor of DPP-IV, methionyl-2(S)-cyano-pyrrolidine. In the present study, we tested the effects of two competitive, selective DPP-IV inhibitors, sitagliptin (4 mg/kg) and diprotin A (2 mg/kg), administered at postnatal days 5 - 18 on the emotional and motivational behavior of adolescent and adult rats. We observed increased anxiety in one-month-old diprotin A- or sitagliptin-treated rats in the elevated plus maze;diprotin A also enhanced the animals’ anxiety score using a ranked scale for evaluating anxiety and phobias. In the sucrose consumption and preference test, depressive-like behavior was pronounced in both the diprotin A- and sitagliptin-treated one-month-old animals, while only the diprotin A-treated rats exhibited a decrease in sucrose consumption at the age of 2 months. The diprotin A-treated rats also demonstrated behavioral despair and decreased activity in the forced swimming test within 1 - 3 months of age. Increased aggression was observed in 1 - 3-month-old diprotin A-treated rats and in two-month-old sitagliptin-treated rats. These findings support the hypothesis that DPP-IV is involved in the genesis of emotional and motivational disorders. Additionally, the results show that diprotin А impairs the adolescent and adult rats’ behavior more significantly than sitagliptin when the animals were treated with the DPP-IV inhibitors in the early postnatal period.

Hypoxic Preconditioning Eliminates Differences in the Innate Resistance of Rats to Severe Hypoxia

Hypoxic preconditioning is able to increase the body’s resistance to hypoxic/ischemic stress. Understanding how to apply the hypoxic response to initiate the protective mechanism of ischemic preconditioning is a high priority. However, the relationship between innate resistance to hypoxic stress and preconditioning efficiency of moderate hypoxia has been poorly studied. In our work, the efficiency of single moderate hypobaric hypoxia (HBH) for resistance to severe hypobaric hypoxia (SHBH) was studied on intact rats and those pre-tested under SHBH with low, intermediate and high resistance to hypoxia. HBH has a significant preconditioning action on the resistance to hypoxia over a wide range from 270 to 1464 s (4.5 to 24.5 min) and at the same time eliminates the differences in the endurance under SHBH between all rat groups. It is concluded that 1) HBH preconditioning efficiency does not depend on an innate resistance to SHBH and prior hypoxic experience of rats;and 2) the pretesting to severe hypoxia has no value for predicting the hypoxic preconditioning efficiency and study of adaptive mechanisms.

Wilson disease-the impact of hyperimmunity on disease activity:A case report

BACKGROUND In Wilson disease lack of biliary copper excretion causes hepatocellular injury by accumulation of free toxic copper.Its overspill to serum accounts for neuronal damage as second common manifestation.Therapy with copper chelators or zinc targets the removal of this free copper.However,in some patients liver disease persists for unknown reason despite normalized free copper.The discovery of a hyperimmunity as a contributing pathogenetic factor was discovered in this case report with implication also for other liver diseases.CASE SUMMARY A 9-year-old girl was diagnosed in August 2009 by family screening of having asymptomatic Wilson disease with elevated transaminases.Already at time of diagnosis antinuclear antibodies(ANA)were elevated without hyperimmunoglobulinemia(immunoglobulin G,IgG).After one year of therapy with Dpenicillamine transaminases normalized together with free serum copper.Under continuous therapy with copper chelators free copper remained normal until today,whereas transaminases raised to alanine aminotransferase values of 571 U/L in December 2019.For hyperimmunity a tentative steroid course on top of Dpenicillamine improved transaminases.Thus,hyperimmunity may have impact on liver inflammation after control of the metabolic disturbance.A retrospective cohort study confirmed the common association of elevated transaminases with ANA,but no IgG elevation.CONCLUSION This hyperimmune-triggered condition may represent a new entity which per se or on top of other liver diseases induces liver inflammation responsive to steroids.

Propionyl-L-carnitine hydrochloride for treatment of mild to moderate colonic inflammatory bowel diseases

AIM:To assess clinical and endoscopic response to propionyl-L-carnitine hydrochloride(PLC) in colonic inflammatory bowel disease.METHODS:Patients suffering from mild to moderate ulcerative colitis(UC) or Crohn's disease(CD) colitis,with disease activity index(DAI) between 3 and 10 and under stable therapy with oral aminosalicylates,mercaptopurine or azathioprine,for at least 8 wk prior to baseline assessments,were considered suitable for enrollment.Fourteen patients were enrolled to assume PLC 2 g/d(two active tablets twice daily) orally.Clinical-endoscopic and histological activity were assessed by DAI and histological index(HI),respectively,following a colonoscopy performed immediately before and after 4 wk treatment.Clinical response was defined as a lowering of at least 3 points in DAI and clinical remission as a DAI score ≤ 2.Histological response was defined as an improvement of HI of at least 1 point.We used median values for the analysis.Differences pre-and post-treatment were analyzed by Wilcoxon signed rank test.RESULTS:All patients enrolled completed the study.One patient,despite medical advice,took deflazacort 5 d before follow-up colonoscopy examination.No side effects were reported by patients during the trial.After treatment,71%(SE 12%) of patients achieved clinical response,while 64%(SE 13%) obtained remission.Separating UC from CD patients,we observed a clinical response in 60%(SE 16%) and 100%,respectively.Furthermore 60%(SE 16%) of UC patients and 75%(SE 25%) of CD patients were in clinical remission after therapy.The median DAI was 7 [interquartile range(IQR):4-8] before treatment and decreased to 2(IQR:1-3)(P < 0.01) after treatment.Only patients with UC showed a significant reduction of DAI,from a median 6.5(IQR:4-9) before treatment to 2(IQR:1-3) after treatment(P < 0.01).Conversely,in CD patients,although displaying a clear reduction of DAI from 7(IQR:5.5-7.5) before therapy to 1.5(IQR:0.5-2.5) after therapy,differences observed were not significant(P = 0.06).Seventy-nine percent(SE 11%) of patients showed improvement of HI of at least 1 point,while only one CD and two UC patients showed HI stability;none showed HI worsening.Median HI decreased from 1(IQR:1-2),to 0.5(IQR:0-1) at the endoscopic control in the whole population(P < 0.01),while it changed from 1(IQR:1-2) to 0.5(IQR:0-1) in UC patients(P < 0.01) and from 1.5(IQR:1-2) to 0.5(IQR:0-1) in CD patients(P = not significant).The two sample tests of proportions showed no significant differences in clinical and histological response or in clinical remission between UC and CD patients.No side effects were reported during treatment or at 4 wk follow-up visit.CONCLUSION:PLC improves endoscopic and histological activity of mild to moderate UC.Further studies are required to evaluate PLC efficacy in colonic CD patients.

Cytokines and T Helper Cells in Diabetic Nephropathy Pathogenesis

Diabetic Nephropathy (DN) is considered the main cause of end stage kidney disease around the world. However, its pathogenesis is not completely established. More than just a direct consequence of chronic glycemic changes, recent studies had suggested Diabetic Nephropathy could be considered an inflammatory disease. It has been shown that concentrations of pro-inflammatory cytokines, as IL-1, IL-6, IL-18, IL-33, IFN-γ and TNF-α actively participate in development and progression of DN, and thus, are involved in pathogenesis. Besides, changes in acquired immune response, especially the presence of cellular immune response profiles of pro-inflammatory and effector nature, mainly Th1 and Th17, as the imbalance between interaction of cytokines and T regulatory cells, foment the onset and progression of DN. Here we summarize the main evidences that support the critical role of the immune system in this condition. These new conceptual advances in DN understanding are essential for development of new the rapeutical strategies and prognostic factors, which could be protagonists or adjuvants to the current ones, leading ultimately to a better clinical management of DN patients.

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.

Effects of Calcium on the GABA_A-Coupled CI^-/HCO₃^--ATPase from Plasma Membrane of Rat Brain

The work is a study of the influence of Ca2+ (0.01 - 1 mM) on neuronal CI-, HCO3-, -ATPase complex: an enzyme that is a CI--pump which is functionally and structurally coupled to GABAA-receptors. It is found that influence of Ca2+ on the multifunctional complex starts at concentration of 50·M and at concentration of 0.1 mM, it reduces the “basal” one and increases the CI-, HCO3-, -stimulated Mg2+-ATPase activities. GABA (0.1 - 100μM) activates the “basal” Mg2+-ATPase activity in the ab-sence of calcium. The effect of GABA on the enzyme in the presence of 0.01 ·M Ca2+ does not change. At the same time, 1 mM Ca2+eliminates the GABA effect on the “basal” Mg2+-ATPase activity. Competitive blocker of GABAA-receptors bicuculline (5 - 20 μM) in the absence of Ca2+ ions elimi-nates the stimulation of the “basal” Mg2+-ATPase by anions. When 0.25 mM Ca2+ is added to the in-cubation medium the inhibitory bicuculline effect on the enzyme does not appear. We found that 0.1 mM o-vanadate (protein tyrosine phosphatase blocker) reduces the GABA-activated ATPase activity. At the same time, 0.1 mM genistein (a protein tyrosine kinase blocker) has no effect on enzyme activity. In the presence of Ca2+ (0.25 mM), the effect of o-vanadate on the “basal” and CI-, HCO3-, -ATPase activities does not appear. It is shown for the first time that high concentrations of Ca2+prevent the action of GABAA-ergic ligands on the study ATPase. It is assumed that there is the involvement of protein kinases and protein phosphatases in the modulation of the enzyme activity by calcium. The observed effect of calcium on the ATPase may play an important role in the study of the mechanisms of epileptogenesis and seizure activity.

Infliximab does not increase colonic cancer risk associated to murine chronic colitis

AIM To explore the influence of Infliximab(IFX) on cancer progression in a murine model of colonic cancer associated to chronic colitis.METHODS AOM/DSS model was induced in C57BL/6 mice. Mice were injected with IFX(5 mg/kg) during each DSS cycle while control mice received saline. Body weight, occult blood test and stool consistency were measured to calculate the disease activity index(DAI). Mice were sacrificed at week 10 and colons were analyzed macroscopically and microscopically for number of cancers and degree of inflammation. MTT assay was performed on CT26 to evaluate the potential IFX role on metabolic activity and proliferation. Cells were incubated with TNF-α or IFX or TNF-α plus IFX, and cell vitality was evaluated after 6, 24 and 48 h. The same setting was used after pre-incubation with TNF-α for 24 h.RESULTS IFX significantly reduced DAI and body weight loss in mice compared with controls, preserving also colon length at sacrifice. Histological score was also reduced in treated mice. At macroscopic analysis, IFX treated mice showed a lower number of tumor lesions compared to controls. This was confirmed at microscopic analysis, although differences were not statistically significant. In vitro, IFX treated CT26 maintained similar proliferation ability at MTT test, both when exposed to IFX alone and when associated to TNF-α.CONCLUSION IFX did not increase colonic cancer risk in AOM-DSS model of cancer on chronic colitis nor influence directly the proliferation of murine colon cancer epithelial cells.