Protein Amino Research Articles

Гістохімічне дослідження процесів окиснювальної модифікації білків та обмеженого протеолізу в ендотелії судин міометрію у проекції плацентарного ложа матки при залізодефіцитній анемії вагітних

Utero-placental bed is the cumulation of gestationally altered endometrium at the place of ovum attachment to the uterine wall. As far as the protein oxidative modification and limited proteolysis in iron deficiency anemia are due to the fact that in conditions of hypoxia, free radical processes in the blood and tissues are enhanced, and iron deficiency is additionally able to cause hemodynamic disorders because of endothelial dysfunction in the vessels of the utero-placental area. The purpose of the study was to establish histochemical features of protein oxidative modification and limited proteolysis in the endotheliocytes of myometrial vessels in the projection of the utero-placental area depending on the degree of iron deficiency anemia in pregnant women. Materials and methods. By histochemical methods of Mikel Calvo, using reactions with bromophenol blue on "acidic" and "basic" proteins, and the method of A. Yasumа and T. Ichikawa, ninhydrin-Schiff reaction to free amino groups of proteins to assess the degree of limited proteolysis, in combination with computer microspectrophotometry and microdensitometry, quantitative characteristics of oxidative modification of proteins and limited proteolysis in endotheliocytes of myometrial segments of the utero-placental vessels in iron deficiency anemia of pregnant women were established. 74 biopsies of the observed uterine-placental area in physiological pregnancy and gestation based on iron deficiency anemia of I, II and III degrees of severity were investigated. Results and discussion. In physiological pregnancy, the intensity of oxidative modification of proteins and limited proteolysis is the lowest in endotheliocytes of myometrial segments of the spiral arteries and the highest one is in the endothelium of the vessels of the microcirculatory tract of the utero-placental area. In gestations based on iron deficiency anemia, intensification of proteins oxidative modification and limited proteolysis in the endothelium of all types of myometrial vessels of the projection of the utero-placental bed correlates with the severity of anemia. Iron deficiency anemia greatly affects the modification of proteins in the endothelial cells mostly of myometrial segments of spiral arteries of the placental bed. Conclusion. Intensification of protein oxidative modification and limited proteolysis in endotheliocytes of all type vessels of myometrium of the uterine-placental area formed by iron deficiency can be considered as a significant factor of endothelial dysfunction and a predictor of hemodynamic disorders of the placental bed

Carbamylation of elastic fibers is a molecular substratum of aortic stiffness

Because of their long lifespan, matrix proteins of the vascular wall, such as elastin, are subjected to molecular aging characterized by non-enzymatic post-translational modifications, like carbamylation which results from the binding of cyanate (mainly derived from the dissociation of urea) to protein amino groups. While several studies have demonstrated a relationship between increased plasma concentrations of carbamylated proteins and the development of cardiovascular diseases, molecular mechanisms explaining the involvement of protein carbamylation in these pathological contexts remain to be fully elucidated. The aim of this work was to determine whether vascular elastic fibers could be carbamylated, and if so, what impact this phenomenon would have on the mechanical properties of the vascular wall. Our experiments showed that vascular elastin was carbamylated in vivo. Fiber morphology was unchanged after in vitro carbamylation, as well as its sensitivity to elastase degradation. In mice fed with cyanate-supplemented water in order to increase protein carbamylation within the aortic wall, an increased stiffness in elastic fibers was evidenced by atomic force microscopy, whereas no fragmentation of elastic fiber was observed. In addition, this increased stiffness was also associated with an increase in aortic pulse wave velocity in ApoE−/− mice. These results provide evidence for the carbamylation of elastic fibers which results in an increase in their stiffness at the molecular level. These alterations of vessel wall mechanical properties may contribute to aortic stiffness, suggesting a new role for carbamylation in cardiovascular diseases.

Role of saturated and unsaturated fatty acids on dicarbonyl-albumin derived advanced glycation end products in vitro.

Glycation is a non-enzymatic reaction that occurs between the free amino group of proteins and reducing sugars and/or lipids, leading to the formation of advanced glycation end products (AGEs). The reaction also produces reactive oxygen species that have detrimental effects on cellular and extracellular proteins. Aminoguanidine is a known inhibitor of AGEs, and some fatty acids are known to have a beneficial role in vivo by reducing inflammation and oxidative stress. However, the role of fatty acids on AGE formation has not been thoroughly reported. We investigated the role of a range of fatty acids in the formation of AGEs and their reactive intermediates using an in vitro BSA-dicarbonyl model. The model assessed a time-dependent (0-72h) and dicarbonyl concentration (0-2mM) -dependent studies for the optimal formation of AGEs. A 72h time point was found to be optimal for the reaction of BSA with either methylglyoxal (MGO) or glyoxal (GO) to generate AGE-BSA complexes. When arachidonic, eicosapentaenoic or docosahexaenoic acids were included in the reaction, a significant decrease in protein-bound fluorescent AGEs was seen compared totherespective controls. In contrast, saturated and 18 carbon polyunsaturated fatty acids showed no significant activity. Liquid chromatography-mass spectrometry (LC-MS/MS) analysis showed saturated fatty acids significantly decreased the production of Nε-carboxymethyllysine (CML) and Nε-carboxyethyllysine (CEL) from GO and MGO models, respectively, whilst increasing methylglyoxal-derived hydroimidazolone (MG-H1). In contrast, arachidonic, eicosapentaenoic and docosahexaenoic acids did not significantly change either CEL or MG-H1 compared to no treatment controls whilst significantly reducing CML levels.

Deep learning takes on protein folding

Protein Folding In 1972, Anfinsen won a Nobel prize for demonstrating a connection between a protein's amino acid sequence and its three-dimensional structure. Since 1994, scientists have competed in the biannual Critical Assessment of Structure Prediction (CASP) protein-folding challenge. Deep learning methods took center stage at CASP14, with DeepMind's Alphafold2 achieving remarkable accuracy. Baek et al. explored network architectures based on the DeepMind framework. They used a three-track network to process sequence, distance, and coordinate information simultaneously and achieved accuracies approaching those of DeepMind. The method, RoseTTA fold, can solve challenging x-ray crystallography and cryo–electron microscopy modeling problems and generate accurate models of protein-protein complexes. Science , abj8754, this issue p. [871][1] [1]: /lookup/doi/10.1126/science.abj8754

Genome-Wide Analysis of the Amino Acid Auxin Permease (AAAP) Gene Family and Identification of an AAAP Gene Associated with the Growth and Reproduction of the Brown Planthopper, Nilaparvata lugens (Stål)

Simple SummaryAmino acids are one of the essential nutrients in organisms and play unique roles in multiple life activities. However, most insects cannot synthesize several amino acids and must acquire them from dietary sources. Diffusion of amino acids into and out of insect cells is heavily dependent on amino acid transporters. The amino acid auxin permease represents one of the most important amino acid transporter gene families in insects. However, amino acid transporters in most insects are not well understood. Here, we performed genome-wide identification of the amino acid auxin permeases in the brown planthopper (BPH), Nilaparvata lugens, a devastating pest that feeds on the phloem sap of rice plants. The molecular traits and evolutionary patterns of these putative amino acid auxin permeases in BPH were analyzed. An amino acid auxin permease which was predicted to regulate BPH nymphal growth and female fecundity was identified and functionally validated through RNA interference and bioassay experiments. Our results provide a basis for further functional research on the amino acid auxin permeases in BPH and suggest new ideas for the management of this pest.Amino acids play a vital role in several biological processes in organisms and are mainly acquired through diet by most insects. The amino acid auxin permease (AAAP) transporter family is an important amino acid transporter gene family in insects for the transportation of amino acids into and out of cells across the plasma membrane. Here, we identified 21 putative AAAP family members in the genome of the brown planthopper (BPH), Nilaparvata lugens, a devastating pest that feeds only on the phloem sap of rice plants. Molecular characteristic analysis indicated large variations in protein features and amino acid sequences among the predicted AAAP family members in BPH. Phylogenetic analysis clustered these AAAP transporters into three subgroups, with the members in the same group sharing a similar pattern of conserved motif distribution. Through ortholog gene recognition and spatiotemporal gene expression analysis, the AAAP gene NlAAAP07, which was predicted to regulate BPH larval growth and female fecundity, was identified. RNA interference (RNAi)-mediated suppression of NlAAAP07 significantly postponed the duration of 3rd instar nymphs developing into adults from 7.4 days to 9.0 days, and decreased the oviposition amount and egg hatching rate of females by 30.7% and 11.0%, respectively. Our results provide a foundation for further functional analysis of AAAP transporters in BPH.

Abstracts

Abstracts

The Effect of formetanate hydrochloride on the glycated human hemoglobin

ABSTRACTGlycation refers to the nonenzymatic glycosylation of the free amino groups of proteins and sugars. Advanced glycation end products (AGEs) is the final stage in glycation process. AGEs cause many complications in diabetic’s patients. Formetanate hydrochloride is a highly effective pesticide widely used in agriculture. Hence, all human beings, both healthy and diabetics affected patients, can be exposed to this toxin. Therefore, the purpose the present research is to study, the effect of Formetanate hydrochloride upon the glycated human hemoglobin (GHb). To form glycated hemoglobin, Hb was incubated with glucose for 35 days under physiological conditions (dark, 37Ċ and pH 7.4). The effect of the toxin on GHb was investigated via docking studies, flurometry, and UV-Vis and circular dichroism spectroscopy. Incubating Hb with glucose could degrade the structure the protein. Samples contained GHb and formetanate hydrochloride showed remarkable changes in structure; Heme-group degradation and an increase in β-sheet structures was also observed. The results of docking studies were consistent with these results. As diabetes is rapidly expanding in today's world and formetanate hydrochloride is widely used in agriculture, the impact of this toxin on these patients will be very important. According to the results obtained, this toxin can have more destructive effect on the glycated Hb in these patients.

Enhanced photoelectron transfer from light-harvesting antenna of phycocyanin to Fe3O4 hierarchical structure

Phycocyanin, which contains proteins and chromophore, is a natural light capturer for the photosynthesis process of cyanobacteria, while its artificial application as light antenna for sensitizing semiconductors is highly restricted due to low charge transfer efficiency at the interface. In this work, we show how to improve the transfer efficiency of photo-electrons from a new point of view. It is found that the conformation change of proteins is a key to promote photoelectrons transfer from phycocyanin antenna to the surface of hierarchical Fe3O4 microsphers. Conformation change was induced by electrostatic interaction between the carboxyl groups on Fe3O4 micropheres and the amino groups of proteins’ backbone. During the process of conformation change, hydrogen bonds formed between proteins and the surface of Fe3O4 microspheres played a role in stabilizing proteins’ structure to achieve polymeric steric stabilization. Due to this strategy, photocurrent density was enhanced by 5.4 times, photovoltage increased by 2 fold, and majority carriers in the space charge region were improved by 35%. Electron transfer path from phycocyanin to the interface was elucidated based on photoelectronic and photoluminescent studies. Meanwhile, we noticed IPCE increased at 650–700 nm, which might be related to the allosteric effect of protein or electron tunneling.

Development of aldehyde and similar-to-aldehyde tanning agents

Aldehyde and similar-to-aldehyde tanning agents were used in oil tanning and smoke tanning in ancient times. The aldehyde group reacts with the protein amino group in electrophilic form to obtain the preservation stability and practical function of fur and leather. The results showed that aldehyde-tanned leather can promote the hydrothermal stability of skin collagen and has better water and sweat resistance properties than chrome tanning. However, aldehyde tanning agents always lack sufficient coulombic attraction to penetrate well into skin collagen, and some aldehydes have biotoxicity and color, are not easy to dissolve and have high manufacturing costs. In this paper, the structure and application characteristics of some aldehydes are reviewed. According to prior theory and practice, the development of new aldehyde tanning agents and additives has good prospects and significance for providing substitutes for chrome tanning agents.

Effects of a xylanase and beta-glucanase enzyme combination on growth performance of broilers fed maize-soybean meal-based diets

The following study evaluated effects of a xylanase and beta-glucanase combination on growth performance of broilers fed energy reduced versus nutritionally adequate maize-soybean meal-based diets. A total of 648, one-day-old male broilers (Ross 308) were assigned to floor-pens (24 birds/pen, nine pens/treatment, three treatments) in a randomised block design. Treatments included: (1) a nutritionally adequate positive control diet (PC); (2) a negative control (NC) diet in which energy, crude protein and digestible amino acids were reduced by 3.4% (-105 kcal apparent metabolisable energy), 2.3% and 1.2 to 3.0% vs PC, respectively; and (3) NC plus a xylanase and beta-glucanase combination that supplied 1,220 U xylanase and 152 U beta-glucanase per kilogram of final feed. All diets contained a background of 500 FTU/kg phytase and were offered to birds ad libitum. Birds fed NC showed reduced average daily gain (ADG) by -6.1% (P<0.05); increased feed conversion ratio (FCR) by 9.2 points (P<0.05), and overall (d 1-35) body weight corrected FCR which was increased by 9.4 points (P<0.05) vs the PC group. Enzyme supplementation increased final BW (+4.2%, P<0.05), ADG (+5.4%, P<0.05) and tended to reduce FCR (+7.5 points, P=0.054) from d 22-35 vs NC, without affecting average daily feed intake. Improvements in performance due to the enzyme combination were equivalent to performance on the PC diet in all cases. The results suggested that significant improvements in growth performance of broilers fed maize-soybean meal-based diets which had been reduced in energy and nutrients can be realised by supplementation with xylanase in combination with beta-glucanase.

Роль конечных продуктов гликирования в развитии и прогрессировании диабетической нейроостеоартропатии

Diabetic neuroarthropathy (DNOAP, Charcot’s foot) is a serious complication of diabetes mellitus, the genesis of which is not fully understood. In most cases, this pathology is diagnosed late, which leads to the development of severe deformities of the foot, up to the loss of support ability of the limb. There is no single hypothesis for the formation of Charcot’s foot, but there are factors predisposing to its development, as well as a few likely provoking events. Excessive formation and accumulation of end products of glycation may play an important role in the pathogenesis of this complication of diabetes. End products of glycation (AGE) are a variety of compounds formed as a result of a non-enzymatic reaction between carbohydrates and free amino groups of proteins, lipids and nucleic acids. There are various factors that lead to the accumulation of AGE in the human body. Allocate endogenous and exogenous factors. The former include certain diseases, such as diabetes mellitus, renal failure, which accelerate glycation processes. Exogenous factors leading to the formation of lipo-oxidation and glyco-oxidation products include tobacco smoke and prolonged heat treatment of food. This review provides information on the role of glycation end products in the development and progression of complications in patients with diabetes mellitus.

Correlation between serum carnitine level and Soluble Receptors for Advance Glycation End Products(sRAGE) in Clomiphene Citrate Resistant- PCOS Women

The most frequently diagnosed condition in women at the age of reproduction is the polycystic ovarian syndrome (PCOS).it could be related to a complex endocrine condition, due to its heterogeneity and uncertainty about its etiology, as the clinical highlights of PCOS incorporate those related to reproductive signs such as decreased frequency of ovulation, irregular menstrual cycles, decreased fertility. Carnitine plays a substantial role in weight loss, glucose tolerance, insulin function and fatty acid metabolism. Thus carnitine plays a crucial role in controlling obesity, insulin resistance, oxidative stress that are associated with PCOS .While, AGEs are a diverse group of reactive molecules that are formed endogenously by non-enzymatic reactions of carbonyl group of carbohydrates with free amino groups of proteins, nucleic acids or lipids. The soluble form of receptors of AGE (sRAGE) could play an important role in management obesity, insulin resistance, hyperandrogenism, oxidative stress which could be related to PCOS. This study was aimed to investigate serum levels of carnitine & soluble receptors for advanced glycation end products (sRAGE) in clomiphene resistant PCOS .Besides assessing the correlation between serum levels of carnitine ,as well as, soluble receptors of AGE with hormonal ( LH, FSH& Testosterone) and metabolic ( serum glucose , serum insulin & HOMA-IR) markers in these patients .
 The study included thirty women with clomiphene resistant PCOS and thirty apparently healthy women, as a control .In order to measure serum total carnitine and serum soluble receptor of advance glycation end product (sRAGE in PCOS and control groups.
 The results of our study have shown a decreased serum levels of total carnitine in PCOS group in comparison with control group (48.05 and 59.73 nmol/ml, respectively), but there was no significant elevation in serum levels of sRAGE in patients group as compared with control group .In addition to a significant correlation between serum total carnitine and serum sRAGE levels (r=0.45, P-value=0.03). 
 In conclusion serum total carnitine level was low in Clomiphene resistant-PCOS patients in comparison with control group. Although, sRAGE levels in clomiphene resistant- PCOS patients were not significantly different from the age and BMI-matching controls, but a significant correlation between serum total carnitine and sRAGE was detected.
 Key words: Poly cystic ovarian syndrome, soluble receptor of advance glycation end products (sRAGE) , SerumTotal Carnitine

In vitro Antidiabetic, Antioxidant and Antiglycation Activity of Ethanolic Leaf Extract of Gomphrena globosa (Linn.)

G. globosa L. is an everlasting tropical annual plant reported to possess several biological activities for curing ailments such as arthritis, diabetes, asthma, bronchitis and also known to possess anti tussive, anti-oxidant, anti-asthmatic and anti-cancer activities. The amino group of protein and carbonyl group of reducing sugar undergoes a non-enzymatic protein glycation reaction that leads to major complications in Diabetic patients. Several antiglycation agents of natural or synthetic origin are there to inhibit protein glycation reaction. But due to its toxicity, antiglycation agents of plant origin are gaining importance as an effective strategy to minimize diabetic complications. The aim of this study was to evaluate the antidiabetic, antioxidant and antiglycation activity of ethanolic leaf extract of G. globosa. The ethanolic leaf extract exerted its antidiabetic effect by inhibiting the activity of α-amylase (p<0.05) resulting in the delayed digestion of the dietary carbohydrates and lowering the amount of glucose liberated. The highest scavenging was observed at 500 μg concentrations and the percent inhibition was found to be 50.80% for DPPH assay and 57.24% (p<0.05) for hydroxyl free radical scavenging assay. 25mM of glucose concentration showed the highest uptake of glucose. The glucose adsorption capacities of G. globosa ethanolic leaf extract was directly proportional to the glucose concentration in the medium resulting in significantly higher glucose adsorption. The effect of antiglycation activity of G. globosa ethanolic leaf extract was found to be increasing with increase in time. The inhibition of ethanolic leaf extract was found to be maximum (27.66%) at 72 hr, followed by 23.7% at 48 hr and 13.7% at 24 hr for fructation with ROS modification/UV/guanosine. This result indicates that ethanolic leaf extract of G. globosa possess significant activity at desirable concentration.

Collagen Biosynthesis, Processing, and Maturation in Lung Ageing.

In addition to providing a macromolecular scaffold, the extracellular matrix (ECM) is a critical regulator of cell function by virtue of specific physical, biochemical, and mechanical properties. Collagen is the main ECM component and hence plays an essential role in the pathogenesis and progression of chronic lung disease. It is well-established that many chronic lung diseases, e.g., chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF) primarily manifest in the elderly, suggesting increased susceptibility of the aged lung or accumulated alterations in lung structure over time that favour disease. Here, we review the main steps of collagen biosynthesis, processing, and turnover and summarise what is currently known about alterations upon lung ageing, including changes in collagen composition, modification, and crosslinking. Recent proteomic data on mouse lung ageing indicates that, while the ER-resident machinery of collagen biosynthesis, modification and triple helix formation appears largely unchanged, there are specific changes in levels of type IV and type VI as well as the two fibril-associated collagens with interrupted triple helices (FACIT), namely type XIV and type XVI collagens. In addition, levels of the extracellular collagen crosslinking enzyme lysyl oxidase are decreased, indicating less enzymatically mediated collagen crosslinking upon ageing. The latter contrasts with the ageing-associated increase in collagen crosslinking by advanced glycation endproducts (AGEs), a result of spontaneous reactions of protein amino groups with reactive carbonyls, e.g., from monosaccharides or reactive dicarbonyls like methylglyoxal. Given the slow turnover of extracellular collagen such modifications accumulate even more in ageing tissues. In summary, the collective evidence points mainly toward age-induced alterations in collagen composition and drastic changes in the molecular nature of collagen crosslinks. Future work addressing the consequences of these changes may provide important clues for prevention of lung disease and for lung bioengineering and ultimately pave the way to novel targeted approaches in lung regenerative medicine.

Plasma and Urinary Amino Acid-Derived Catabolites as Potential Biomarkers of Protein and Amino Acid Deficiency in Rats.

Objective: Dietary intakes must cover protein and essential amino acid (EAA) requirements. For this purpose, different methods have been developed such as the nitrogen balance method, factorial method, or AA tracer studies. However, these methods are either invasive or imprecise, and the Food and Agriculture Organization of the United Nations (FAO, 2013) recommends new methods and, in particular, metabolomics. The aim of this study is to determine total protein/EAA requirement in the plasma and urine of growing rats. Methods: 36 weanling rats were fed with diets containing 3, 5, 8, 12, 15, and 20% protein for 3 weeks. During experimentation, urine was collected using metabolic cages, and blood from the portal vein and vena was taken at the end of the experiment. Metabolomics analyses were performed using LC-MS, and the data were analyzed with a multivariate analysis model, partial least Squares (PLS) regression, and independent component-discriminant analysis (ICDA). Each discriminant metabolite identified by PLS or ICDA was tested by one-way ANOVA to evaluate the effect of diet. Results: PLS and ICDA allowed us to identify discriminating metabolites between different diet groups. Protein deficiency led to an increase in the AA catabolism enzyme systems inducing the production of breakdown metabolites in the plasma and urine. Conclusion: These results indicate that metabolites are specific for the state of EAA deficiency and sufficiency. Some types of biomarkers such as AA degradation metabolites appear to be specific candidates for protein/EAA requirement.

Effects of cadmium stress on physiological indexes and fruiting body nutritions of Agaricus brasiliensis

In this study, 0, 0.5, 1, 1.5, 2, 4, 6 and 8 mg·kg−1 of cadmium were added to the cultivation materials. In order to study the effects of different concentrations of Cd stress on J1 and J77, the contents of antioxidant enzymes, proline and malondialdehyde, Cd content, agronomic traits and yield of fruiting bodies of Agaricus brasiliensis were determined, and the nutritional components such as polysaccharide, triterpene, protein, total sugar and total amino acid were determined. The results showed that the physiological indexes of strain J1 and J77 changed regularly under different concentrations of Cd stress. J1 was a high absorption and low tolerance variety, while J77 was a low absorption and high tolerance variety. Low concentration of Cd promoted the growth of strain J1, and higher concentration of Cd promoted the growth of strain J77. The contents of protein and total amino acids in the two strains changed greatly, followed by polysaccharides, which indicated that Cd stress had the greatest impact on the three nutrients, and other nutrients were not sensitive to Cd stress.

Growth response nitrogen metabolism of grafted cucumber fertilized with different ratios of nitrate: ammonium fertilizer

The use of an endemic plant as rootstock has many merits but its application for cucurbits production has not been extensively investigated. The present study determined the growth responses of grafted cucumber using two endemic rootstocks from Cucurbita pepo L. fertilized with different ratios of nitrate (NO3-): ammonium (NH4+) fertilizer. A greenhouse study was carried out using cucumber (C. sativus ‘Dominos’) grafted on two accessions of Cucurbita pepo L. collected from Babol and Isfahan with the control being ungrafted C. sativus ‘Dominos’. Different ratios of NO3-/NH4+ as follows: 100:0 (NO3− alone), 25/75, 50/50, 75/25 and 0/100 (NH4+ alone) were applied. It was found that different rootstock has the same physiology but different growth attributes. The growth of the ungrafted cucumber was lower than the grafted ones, and Babol showed better or equal growth compared to the Isfahan rootstock. The NO3-/NH4+ effect on growth of the cucumber shoot and root fresh and dry weights, root and shoot lengths, nodes, and number of leaves were increased in the 75/25 ratio compared to the other treatments. Grafting on the Isfahan and Babol showed the same effect of N metabolism i.e., grafting increased nitrate reductase activity and NO3- concentration in the 75/25 and the 100/0. Protein content and amino acids content of leaves increased in the grafted cucumber treated with 50/50 NO3-/NH4+. The same response of photosynthesis parameters was observed in the different rootstocks. In conclusion, the result suggested that the grafted ‘Dominos’ on Babol endemic rootstock at 50/50 NO3-/NH4+ ratio gave the high growth.

Amino terminus of cardiac myosin binding protein-C regulates cardiac contractility

Phosphorylation of cardiac myosin binding protein-C (cMyBP-C) regulates cardiac contraction through modulation of actomyosin interactions mediated by the protein's amino terminal (N′)-region (C0-C2 domains, 358 amino acids). On the other hand, dephosphorylation of cMyBP-C during myocardial injury results in cleavage of the 271 amino acid C0-C1f region and subsequent contractile dysfunction. Yet, our current understanding of amino terminus region of cMyBP-C in the context of regulating thin and thick filament interactions is limited. A novel cardiac-specific transgenic mouse model expressing cMyBP-C, but lacking its C0-C1f region (cMyBP-C∆C0-C1f), displayed dilated cardiomyopathy, underscoring the importance of the N′-region in cMyBP-C. Further exploring the molecular basis for this cardiomyopathy, in vitro studies revealed increased interfilament lattice spacing and rate of tension redevelopment, as well as faster actin-filament sliding velocity within the C-zone of the transgenic sarcomere. Moreover, phosphorylation of the unablated phosphoregulatory sites was increased, likely contributing to normal sarcomere morphology and myoarchitecture. These results led us to hypothesize that restoration of the N′-region of cMyBP-C would return actomyosin interaction to its steady state. Accordingly, we administered recombinant C0-C2 (rC0-C2) to permeabilized cardiomyocytes from transgenic, cMyBP-C null, and human heart failure biopsies, and we found that normal regulation of actomyosin interaction and contractility was restored. Overall, these data provide a unique picture of selective perturbations of the cardiac sarcomere that either lead to injury or adaptation to injury in the myocardium.

6-BENZYLAMINOPURINE AND 2, 4-DICHLOROPHENOXYACETIC ACID EFFECT ON CALLUS GENESIS OF Brosimum alicastrum

Brosimum alicastrum seeds contain a high percentage of protein and essential amino acids that contribute to a proper nutrition. This tree is an alternative in the so-called crusade against hunger and its management does not involve the use of agrochemicals. The objective of this research was to evaluate the morphogenic response of foliar explants with two growth regulators, 6-Benzylaminopurine (BAP) and 2,4-Dichlorophenoxyacetic Acid (2,4-D) in the induction of calli. Results demonstrated that the combination of 1.5 mg L-1 BAP and 1 mg L-1 2,4-D (TM) and 1.5 mg L-1 BAP with 2 mg L-1 2,4-D (TN) favored callus growth in 100% of foliar explants. Calli were grown in a period of 20 d, in a culture room at 25 ± 4 °C, with 16 h of illumination. Under these conditions, calli remained in slow growth for four weeks. Those explants that generated callus were sub-cultured in fresh medium without activated charcoal. In TM and TN treatments, the multiplication of the cell mass was favored; in TN globular structures were formed. However, explants the same treatments TM and TN with activated charcoal, and under ambient 29 ± 4 °C conditions increased callus growth, but became friable at two weeks. Thus, TM and TN were the better treatments, but activated charcoal was determined to have a negative effect on callus growth.

Glycation of benign meningioma cells leads to increased invasion.

Meningiomas are the most common non-malignant intracranial tumors. Like most tumors, meningiomas prefer anaerobic glycolysis for energy production (Warburg effect). This leads to an increased synthesis of the metabolite methylglyoxal (MGO). This metabolite is known to react with amino groups of proteins. This reaction is called glycation, thereby building advanced glycation endproducts (AGEs). In this study, we investigated the influence of glycation on two meningioma cell lines, representing the WHO grade I (BEN-MEN-1) and the WHO grade III (IOMM-Lee). Increasing MGO concentrations led to the formation of AGEs and decreased growth in both cell lines. When analyzing the influence of glycation on adhesion, chemotaxis and invasion, we could show that the glycation of meningioma cells resulted in increased invasive potential of the benign meningioma cell line, whereas the invasive potential of the malignant cell line was reduced. In addition, glycation increased the E-cadherin- and decreased the N-cadherin-expression in BEN-MEN-1cells, but did not affect the cadherin-expression in IOMM-Lee cells.