Cathepsin B inhibitor improves developmental competency and cryo-tolerance of in vitro ovine embryos

Background

Cathepsin B is a lysosomal cysteine protease involved in apoptosis and oocytes which have lower developmental competence show higher expression of Cathepsin B. Furthermore, expression of Cathepsin B show a decreasing trend from oocyte toward blastocyst stage.

Results

Present study assessed the effect of cathepsin B inhibitor, E-64, on developmental competency and cryo-survival of pre-implantation ovine IVF derived embryos. Cathepsin B inhibitor was added during day 3 to 8 of development. One μM E-64 was defined as the optimal concentration required for improving blastocyst rate. This concentration also reduced DNA fragmentation and BAX as apoptotic markers while increasing total cell number per blastocyst and improving anti-apoptotic marker, the BCL2. We further showed that addition of 1.0 μM of E-64 during day 3 to 8 of development improved re-expansion and hatching rates of blastocysts post vitrification. E-64 also reduced rate of DNA fragmentation and BAX expression and increased total cell number per blastocyst and BCL2 expression post vitrification. However, addition of E-64 post vitrification reduced the hatching rate.

Conclusion

Therefore, it can be concluded that inhibition of cathepsin B in IVC, not only improves quality and quantity of blastocysts but also improves the cryo-survival of in vitro derived blastocysts.

     

Inhibition of calpain expression by E-64d in the rat retina subjected to ischemia/reperfusion injury

To investigate the effect of E-64d, a selective inhibitor of calpain, on the expression of calpain and calpastatin in rat retina subject to ischemia/reperfusion injury (IRI). An animal model of retinal IRI was set up by increasing the intraocular pressure (110 mmHg) of a rat eye for 1 h. The retinal thickness and morphologic changes were detected by histology. The protein expression of m-calpain (a calpain isoform) in the retina was assessed by immunohistochemistry and Western blot assay. The mRNA of m-calpain as well as calpastatin (an endogenous protein inhibitor of calpain) in the retina was assessed by RT-PCR, and the ratio of m-calpain/calpastatin was then calculated. To evaluate the effect of E-64d on the expression of calpain, the drug (5 microl of 100 microM) was injected intravitreously immediately after IRI. There were retinal edematous changes, particularly in the inner plexiform layer after IRI. The protein expression of m-calpain in the retina was increased 24h after IRI, an effect that was inhibited by E-64d (P < 0.05). The mRNA expression of m-calpain and calpastatin was also increased 24 h and 3 h after IRI, respectively. Neither m-calpain nor calpastatin mRNA expression was influenced by E-64d (P > 0.05). The mRNA ratio of m-calpain to calpastatin was increased at the 6 h, 24 h and 72 h after IRI, and only at 24 h the increase of the ratio of m-calpain to calpastatin was inhibited by E-64d (P < 0.05). In the rat retina of IRI, E-64d inhibits the increase of m-calpain protein expression, as well as the mRNA ratio increase of m-calpain to calpastatin. E-64d also inhibited the retinal damage induced by IRI, suggesting a role for E-64d in the protection of the retinal apoptosis induced by IRI.     

Inhibition of calpain expression by E-64d in the rat retina subjected to ischemia/reperfusion injury

To investigate the effect of E-64d, a selective inhibitor of calpain, on the expression of calpain and calpastatin in rat retina was subjected to ischemia/reperfusion injury (IRI). An animal model of retinal IRI was set up by increasing the intraocular pressure (110 mm Hg) of a rat eye for 1 h. The retinal thickness and morphologic changes were detected by histology. The protein expression of m-calpain (a calpain isoform) in the retina was assessed by immunohistochemistry and Western blot assay. The mRNA of m-calpain, as well as calpastatin (an endogenous protein inhibitor of calpain), in the retina was assessed by RT-PCR, and the ratio of m-calpain/calpastatin was then calculated. To evaluate the effect of E-64d on the expression of calpain, the drug (5 μl of 100 μM) was injected intravitreously immediately after IRI. There were retinal edematous changes, particularly in the inner plexiform layer after IRI. The protein expression of m-calpain in the retina was increased 24 h after IRI, an effect that was inhibited by E-64d (P < 0.05). The mRNA expression of m-calpain and calpastatin was also increased 24 h and 3 h after IRI, respectively. Neither m-calpain nor calpastatin mRNA expression was influenced by E-64d (P > 0.05). The mRNA ratio of m-calpain to calpastatin was increased at the 6 h, 24 h and 72 h after IRI, and only at 24 h the increase of the ratio of m-calpain to calpastatin was inhibited by E-64d (P < 0.05). In the rat retina of IRI, E-64d inhibits the increase of m-calpain protein expression, as well as the mRNA ratio increase of m-calpain to calpastatin. E-64d also inhibited the retinal damage induced by IRI, suggesting a role for E-64d in the protection of the retinal apoptosis induced by IRI. Published in Russian in Molekulyarnaya Biologiya, 2008, Vol. 42, No. 2, pp. 258–264. The text was submitted by the authors in English.     

Conformational mobility of active and E-64-inhibited actinidin

Background

Actinidin, a protease from kiwifruit, belongs to the C1 family of cysteine proteases. Cysteine proteases were found to be involved in many disease states and are valid therapeutic targets. Actinidin has a wide pH activity range and wide substrate specificity, which makes it a good model system for studying enzyme–substrate interactions.

Methods

The influence of inhibitor (E-64) binding on the conformation of actinidin was examined by 2D PAGE, circular dichroism (CD) spectroscopy, hydrophobic ligand binding assay, and molecular dynamics simulations.

Results

Significant differences were observed in electrophoretic mobility of proteolytically active and E-64-inhibited actinidin. CD spectrometry and hydrophobic ligand binding assay revealed a difference in conformation between active and inhibited actinidin. Molecular dynamics simulations showed that a loop defined by amino-acid residues 88–104 had greater conformational mobility in the inhibited enzyme than in the active one. During MD simulations, the covalently bound inhibitor was found to change its conformation from extended to folded, with the guanidino moiety approaching the carboxylate.

Conclusions

Conformational mobility of actinidin changes upon binding of the inhibitor, leading to a sequence of events that enables water and ions to protrude into a newly formed cavity of the inhibited enzyme. Drastic conformational mobility of E-64, a common inhibitor of cysteine proteases found in many crystal structures stored in PDB, was also observed.

General significance

The analysis of structural changes which occur upon binding of an inhibitor to a cysteine protease provides a valuable starting point for the future design of therapeutic agents.     

Epithelial N-cadherin and nuclear β-catenin are up-regulated during early development of human lung

Background  

The aim of this study was to analyze the cell-specific expression of E- and N-cadherin and β-catenin in developing human lung tissues from 12 to 40 weeks of gestation.     

Isolation and characterization of a cysteine protease from the latex of Araujia hortorum fruits

A new protease (araujiain h l) was purified to mass spectroscopy homogeneity from the latex of Araujia hortorum Fourn. (Asclepiadaceae) fruits by ultracentrifugation and ion exchange chromatography. The enzyme has a molecular mass of 24,031 (mass spectrometry) and an isoelectric point higher than 9.3. The optimum pH range for casein hydrolysis was 8.0–9.5. The enzyme showed remarkable caseinolytic activity at high temperatures, although its thermal stability decayed rapidly. The proteinase was activated by thiol compounds and inhibited by common thiol-blocking reagents, particularly E-64 and HgCl₂, suggesting the enzyme belongs to the cysteine protease family. The concentration of active sites as determined by titration with E-64 was 3.3 M. When assayed on N--CBZ-amino acid-p-nitrophenyl esters, the enzyme showed higher preference for the glutamine derivative, followed by those of alanine, asparagine, glycine, and leucine, in decreasing order. Partial homology (36–48%) with other plant cysteine proteinases was observed in an internal fragment obtained by Protease V8 treatment.     

Differential expression of E-cadherin,N-cadherin and beta-catenin in proximal and distal segments of the rat nephron.

Background  

The classical cadherins such as E- and N-cadherin are Ca²⁺-dependent cell adhesion molecules that play important roles in the development and maintenance of renal epithelial polarity. Recent studies have shown that a variety of cadherins are present in the kidney and are differentially expressed in various segments of the nephron. However, the interpretation of these findings has been complicated by the fact that the various studies focused on different panels of cadherins and utilized different species. Moreover, since only a few of the previous studies focused on the rat, information regarding the expression and localization of renal cadherins in this important species is lacking. In the present study, we have employed dual immunofluorescent labeling procedures that utilized specific antibodies against either E- or N-cadherin, along with antibodies that target markers for specific nephron segments, to characterize the patterns of cadherin expression in frozen sections of adult rat kidney.     

Effect of chronic ingestion of the cysteine proteinase inhibitor, E-64, on Colorado potato beetle gut proteinases

Chronic ingestion of the highly active, specific cysteine proteinase inhibitor, E-64, has a profound effect on Colorado potato beetle (CPB) larval growth, development and survival, as well as on adult fecundity. However, the number of insects surviving to the adult stage did not decrease below 26% with increasing E-64 concentration above 1.5 g E-64 cm^–2 leaf surface. The development time to the pupal stage was increased from 13 days, when larvae were reared on control leaves, to 21 days at a concentration of 1.5 g E-64 cm^–2 . The most significant effect of dietary E-64 was on adult fecundity, with mated females reared on untreated leaves laying an average 62 ± 5.7 eggs daily in the first 10 days, and those maintained on 0.5 g E-64 cm^–2, laying only 16 ± 2.4 eggs day^–1. Females given 1 g E-64 cm^–2 laid few if any eggs, but started producing egg masses as large as control insects about 5 days after being switched to control leaves. These effects on the insect life cycle were directly related to the degree of inhibition of cysteine proteinase activity in gut extracts. The general proteinase activity in control extracts was 6.5 ± 0.16 units min^–1 mg gut^–1, which decreased to 1.9 ± 0.16 in guts of insects reared on 1 g E-64 cm^–2. The proportion of proteinase activity inhibitable by E-64 decreased from 66% in control guts to 10-15% in guts from larvae reared on 1 g E-64 cm^–2. The aspartate proteinase inhibitor, pepstatin, decreased proteinase activity by 35% in control guts. There was no induction of pepstatin-inhibitable proteinases in response to inhibition by E-64, and no inhibition of gut enzyme activity by soybean trypsin inhibitor from larvae fed any of the E-64 concentrations. This study demonstrates that proteinase levels must be significantly reduced to have a pronounced effect on larval growth and survival, while fecundity of mated females is affected by lower concentrations of inhibitor. It also suggests that the CPB may be a difficult pest to control using a more specific, plant-derived cysteine proteinase inhibitor, such as oryzacystatin.     

Parallel evolution of histophagy in ciliates of the genus Tetrahymena

Background  

Current evidence suggests that lepidopteran baculoviruses may be divided into two phylogenetic groups based on their envelope fusion proteins. One group utilizes gp64, a low pH-dependent envelope fusion protein, whereas the other employs a protein family (e.g. LD130 in the Lymantria dispar nucleopolyhedrovirus) unrelated to gp64, but that is also low pH-dependent. Database searches with members of the LD130 protein family often record significant levels of homology to envelope proteins from a number of insect retrovirus-like transposable elements of the gypsy class. In this report, the significance of the homology between these two types of envelope proteins is analyzed.     

Evolution of the sugar receptors in insects

Background  

Perception of sugars is an invaluable ability for insects which often derive quickly accessible energy from these molecules. A distinctive subfamily of eight proteins within the gustatory receptor (Gr) family has been identified as sugar receptors (SRs) in Drosophila melanogaster (Gr5a, Gr61a, and Gr64a-f). We examined the evolution of these SRs within the 12 available Drosophila genome sequences, as well as three mosquito, two moth, and beetle, bee, and wasp genome sequences.     

Association Study of Gene LPP in Women with Polycystic Ovary Syndrome

Background

Previous genome-wide association study (GWAS) of polycystic ovary syndrome (PCOS) in Han Chinese population has found that SNPs in LPP gene were nominally significant in PCOS patients (P around 10E-05). Replication of the GWAS was applied to further confirm the relationship between LPP gene and PCOS.

Methods

Three polymorphisms of LPP gene (rs715790, rs4449306, rs6782041) were selected and replicated in additional 1132 PCOS cases and 1142 controls. Genotyping of LPP gene was carried out by Taqman-MGB method.

Results

In rs715790, the allele frequency is significantly different between the PCOS group and the control group. Meta-analysis showed that the allele frequencies of the three SNPs rs715790 (P_meta = 1.89E-05, OR = 1.23), rs4449306 (P_meta = 3.0E-04, OR = 1.10), rs6782041 (P_meta = 2.0E-04, OR = 1.09), were significantly different between PCOS cases and controls.

Conclusions

Our results suggest that LPP gene might be a novel candidate for PCOS.     

Common Variant rs9939609 in Gene FTO Confers Risk to Polycystic Ovary Syndrome

Background

Fat mass and obesity-associated gene (FTO) has been associated with obesity, especially the common variant rs9939609. Polycystic ovary syndrome (PCOS) is a complex endocrine-metabolic disorder and over 50% of patients are overweight/obese. Thus FTO is a potential candidate gene for PCOS but their relationship is confusing and remains to be clarified in different population with a large sample size.

Method

This study was performed adopting a two-stage design by genotyping SNP rs9939609. The first set comprise of 741 PCOS and 704 control subjects, with data from our previous GWAS. The second phase of replication study was performed among another independent group of 2858 PCOS and 2358 control subjects using TaqMan-MGB probe assay. All subjects are from Han Chinese.

Results

The less meaningful association of FTO rs9939609 and PCOS discovered in GWAS (P = 2.47E-03), was further confirmed in the replication study (P = 1.86E-09). Using meta-analysis, the P-meta value has reached 6.89E-12, over-exceeding the genome-wide association level of 5.00E-8. By combination, the P value was 1.26E-11 and after BMI adjustment it remained significant(P = 1.82E-06). To further elucidate whether this association is resulted from obesity or PCOS per se, the samples were divided into two groups–obese and non-obese PCOS, and the results were still positive in obese group (P obese = 5.81E-05, OR = 1.55), as well as in non-obese PCOS group (P non-obese = 7.06E-04, OR = 1.28).

Conclusion

Variant rs9939609 in FTO is associated with PCOS in Chinese women, not only in obese PCOS subjects, but also in non-obese cases.     

Genome-Wide Association Study of Proneness to Anger

Background

Community samples suggest that approximately 1 in 20 children and adults exhibit clinically significant anger, hostility, and aggression. Individuals with dysregulated emotional control have a greater lifetime burden of psychiatric morbidity, severe impairment in role functioning, and premature mortality due to cardiovascular disease.

Methods

With publically available data secured from dbGaP, we conducted a genome-wide association study of proneness to anger using the Spielberger State-Trait Anger Scale in the Atherosclerosis Risk in Communities (ARIC) study (n = 8,747).

Results

Subjects were, on average, 54 (range 45–64) years old at baseline enrollment, 47% (n = 4,117) were male, and all were of European descent by self-report. The mean Angry Temperament and Angry Reaction scores were 5.8±1.8 and 7.6±2.2. We observed a nominally significant finding (p = 2.9E-08, λ = 1.027 - corrected p_gc = 2.2E-07, λ = 1.0015) on chromosome 6q21 in the gene coding for the non-receptor protein-tyrosine kinase, Fyn.

Conclusions

Fyn interacts with NDMA receptors and inositol-1,4,5-trisphosphate (IP3)-gated channels to regulate calcium influx and intracellular release in the post-synaptic density. These results suggest that signaling pathways regulating intracellular calcium homeostasis, which are relevant to memory, learning, and neuronal survival, may in part underlie the expression of Angry Temperament.     

Filaggrin Gene Mutation c.3321delA Is Associated with Various Clinical Features of Atopic Dermatitis in the Chinese Han Population

Background

We confirmed that the filaggrin gene mutation c.3321delA is associated with atopic dermatitis in our previous genome wide association study of the Chinese Han population. c.3321delA is the most common filaggrin gene mutation in Chinese atopic dermatitis patients but is not present in European populations.

Objective

To investigate the genetic model for the c.3321delA mutation and to determine the correlation between c.3321delA and atopic dermatitis clinical phenotypes in the Chinese Han population.

Method

The filaggrin gene mutation c.3321delA was sequenced in 1,080 atopic dermatitis patients and 908 controls from the Chinese population. The χ² test, ANOVA,nonparametric tests and logistic regression were used to investigate the relationship between the c.3321delA genotype and atopic dermatitis clinical phenotypes in the Chinese Han population.

Results

Analyses of the genetic model revealed that the additive model best described the c.3321delA mutation (P = 3.09E-11, OR = 3.43, 95%CI = 2.38–4.96). Stratified analyses showed that the c.3321delA allele frequency distribution is significantly associated with concomitant skin xerosis (P = 1.68E-03, OR = 2.13,95%CI = 1.32–3.46), palmar hyperlinearity (P = 3.64E-17, OR = 4.0,95%CI = 2.86–5.70), white dermatographism (P = 4.25E-03, OR = 1.82,95%CI = 1.22–2.71), food intolerance (P = 1.51E-03, OR = 1.76,95%CI = 1.23–2.50) and disease severity ( P = 9.67E-05).

Conclusion

Our study indicates that the filaggrin gene mutation c.3321delA is associated with clinical phenotypes of atopic dermatitis in the Chinese Han population, which might help us gain a better understanding on the pathogenesis of atopic dermatitis.     

Plasma protein N-glycan signatures of type 2 diabetes

Background

Little is known about enzymatic N-glycosylation in type 2 diabetes, a common posttranslational modification of proteins influencing their function and integrating genetic and environmental influences. We sought to gain insights into N-glycosylation to uncover yet unexplored pathophysiological mechanisms in type 2 diabetes.

Plasmodium falciparum: Differential Sensitivity In Vitro to E-64 (Cysteine Protease Inhibitor) and Pepstatin A (Aspartyl Protease Inhibitor)

ABSTRACT We investigated the effect of a cysteine proteinase inhibitor (E-64) and an aspartyl proteinase inhibitor (Pepstatin A) on asexual erythrocytic stages of Plasmodium falciparum in culture. These two protease inhibitors showed different patterns of activity. E-64 acted preferentially against trophozoite and schizont stages. After 48 h incubation at high concentrations of E-64 (28, 140, 280 μM), growth was totally abolished and the parasites presented characteristic enlarged food vacuoles. Morphological alterations were also seen after shorter incubation periods (6 h at 28 μM) or 12 h at the inhibitory concentration 50% (12 μM), but an additional culture period (24 h) in inhibitor-free medium allowed normal parasite development, demonstrating a parasitostatic effect. E-64 acts on parasite multiplication; the normal merozoite maturation was altered and the normal reinvasion process partially impaired. Pepstatin A used at the inhibitory concentration 50% (4 μM) killed the parasites before trophozoite development and had a major effect on schizonts maturation. No altered parasite development occurred during an additional culture period without Pepstatin A, demonstrating a parasiticidal effect. E-64 and Pepstatin A used in combination inhibit the parasite growth with a strong synergistic effect.     

Whole-genome SNP association analysis of reproduction traits in the Finnish Landrace pig breed

Background

Good genetic progress for pig reproduction traits has been achieved using a quantitative genetics-based multi-trait BLUP evaluation system. At present, whole-genome single nucleotide polymorphisms (SNP) panels provide a new tool for pig selection. The purpose of this study was to identify SNP associated with reproduction traits in the Finnish Landrace pig breed using the Illumina PorcineSNP60 BeadChip.

Methods

Association of each SNP with different traits was tested with a weighted linear model, using SNP genotype as a covariate and animal as a random variable. Deregressed estimated breeding values of the progeny tested boars were used as the dependent variable and weights were based on their reliabilities. Statistical significance of the associations was based on Bonferroni-corrected P-values.

Results

Deregressed estimated breeding values were available for 328 genotyped boars. Of the 62 163 SNP in the chip, 57 868 SNP had a call rate > 0.9 and 7 632 SNP were monomorphic. Statistically significant results (P-value < 2.0E-06) were obtained for total number of piglets born in first and later parities and piglet mortality between birth and weaning in later parity, and suggestive associations (P-value < 4.0E-06) for piglet mortality between birth and weaning in first parity, number of stillborn piglets in later parity, first farrowing interval and second farrowing interval. Two of the statistically significant regions for total number of piglets born in first and later parities are located on chromosome 9 around 95 and 79 Mb. The estimated SNP effect in these regions was approximately one piglet between the two homozygote classes. By combining the two most significant SNP in these regions, favourable double homozygote animals are expected to have 1.3 piglets (P-value = 1.69E-08) more than unfavourable double homozygote animals. A region on chromosome 9 (66 Mb) was statistically significant for piglet mortality between birth and weaning in later parity (0.44 piglets between homozygotes, P-value = 6.94E-08).

Conclusions

Three separate regions on chromosome 9 gave significant results for litter size and pig mortality. The frequencies of favourable alleles of the significant SNP are moderate in the Finnish Landrace population and these SNP are thus valuable candidates for possible marker-assisted selection.     

Determination of Tanshinones in Danshen (Salvia miltiorrhiza) by High‐Performance Liquid Chromatography with Fluorescence Detection after pre‐Column Derivatisation

Introduction

Tanshinones are a major class of bioactive ingredients in the traditional herbal medicines, Danshen (Salvia miltiorrhiza). A sensitive and reliable determination method for tanshinones is useful to ensure the quality of Danshen.

Objective

To develop a sensitive and selective analytical method for tanshinones by high‐performance liquid chromatography (HPLC) with fluorescence detection after pre‐column derivatisation.

Methodology

The proposed method depends on derivatisation reaction of tanshinones with 4‐carbomethoxybenzaldehyde and ammonium acetate forming intensely fluorescent imidazole derivative.

Results

The proposed method provided excellent sensitivity with the detection limits of 3.3 nM (66 fmol/injection), 3.2 nM (64 fmol/injection) and 2.0 nM (40 fmol/injection) for cryptotanshinone, tanshinone I and tanshinone IIA, respectively, without the necessity of complicated instrumentations. The developed method is successfully applied to quantify the contents of tanshinones in Danshen.

Conclusion

The developed method is the first analytical method for tanshinones by fluorescence detection. Since the derivatisation reaction is selective for the o‐quinone structure of tanshinone, the developed method will become a suitable mean for the discovering of tanshinone type diterpenoids from herbal samples. Copyright © 2017 John Wiley & Sons, Ltd.     

Vitamin B12-Impaired Metabolism Produces Apoptosis and Parkinson Phenotype in Rats Expressing the Transcobalamin-Oleosin Chimera in Substantia Nigra

Background

Vitamin B12 is indispensable for proper brain functioning and cytosolic synthesis of S-adenosylmethionine. Whether its deficiency produces effects on viability and apoptosis of neurons remains unknown. There is a particular interest in investigating these effects in Parkinson disease where Levodopa treatment is known to increase the consumption of S-adenosylmethionine. To cause deprivation of vitamin B12, we have recently developed a cell model that produces decreased synthesis of S-adenosylmethionine by anchoring transcobalamin (TCII) to the reticulum through its fusion with Oleosin (OLEO).

Methodology

Gene constructs including transcobalamin-oleosin (TCII-OLEO) and control constructs, green fluorescent protein-transcobalamin-oleosin (GFP-TCII-OLEO), oleosin-transcobalamin (OLEO-TCII), TCII and OLEO were used for expression in N1E-115 cells (mouse neuroblastoma) and in substantia nigra of adult rats, using a targeted transfection with a Neurotensin polyplex system. We studied the viability and the apoptosis in the transfected cells and targeted tissue. The turning behavior was evaluated in the rats transfected with the different plasmids.

Principal Findings

The transfection of N1E-115 cells by the TCII-OLEO-expressing plasmid significantly affected cell viability and increased immunoreactivity of cleaved Caspase-3. No change in propidium iodide uptake (used as a necrosis marker) was observed. The transfected rats lost neurons immunoreactive to tyrosine hydroxylase. The expression of TCII-OLEO was observed in cells immunoreactive to tyrosine hydroxylase of the substantia nigra, with a superimposed expression of cleaved Caspase-3. These cellular and tissular effects were not observed with the control plasmids. Rats transfected with TCII-OLEO expressing plasmid presented with a significantly higher number of turns, compared with those transfected with the other plasmids.

Conclusions/Significance

In conclusion, the TCII-OLEO transfection was responsible for apoptosis in N1E-115 cells and rat substantia nigra and for Parkinson-like phenotype. This suggests evaluating whether vitamin B12 deficit could aggravate the PD in patients under Levodopa therapy by impairing S-adenosylmethionine synthesis in substantia nigra.