Expression and cellular localisation of Trypanosoma cruzi calpains

BACKGROUND Calpains are present in almost all organisms and comprise a family of calcium-dependent cysteine peptidases implicated in crucial cellular functions. Trypanosoma cruzi, the causative agent of Chagas disease, presents an expansion on this gene family with unexplored biological properties. OBJECTIVES Here, we searched for calpains in the T. cruzi genome, evaluated the mRNA levels, calpain activity and the protein expression and determined the cellular localisation in all three parasite life cycle forms. METHODS/FINDINGS Sixty-three calpain sequences were identified in T. cruzi CL Brener genome, with fourteen domain arrangements. The comparison of calpain mRNA abundance by quantitative polymerase chain reaction (qPCR) revealed seven up-regulated sequences in amastigotes and/or bloodstream trypomastigotes and five in epimastigotes. Western Blotting analysis revealed seven different molecules in the three parasite forms, and one amastigote-specific, while no proteolytic activity could be detected. Flow cytometry assays revealed a higher amount of intracellular calpains in amastigotes and/or trypomastigotes in comparison to epimastigotes. Finally, ultrastructural analysis revealed the presence of calpains in the cytoplasm, vesicular and plasma membranes of the three parasite forms, and in the paraflagellar rod in trypomastigotes. CONCLUSION Calpains are differentially expressed and localised in the T. cruzi life cycle forms. This study adds data on the calpain occurrence and expression pattern in T. cruzi.

Calpains of Leishmania braziliensis: genome analysis, differential expression, and functional analysis

BACKGROUND Calpains are proteins belonging to the multi-gene family of calcium-dependent cysteine peptidases that undergo tight on/off regulation, and uncontrolled proteolysis of calpains is associated with severe human pathologies. Calpain orthologues are expanded and diversified in the trypanosomatids genome. OBJECTIVES Here, we characterised calpains in Leishmania braziliensis, the main causative agent of cutaneous leishmaniasis in Brazil. METHODS/FINDINGS In total, 34 predicted calpain-like genes were identified. After domain structure evaluation, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) during in vitro metacyclogenesis revealed (i) five genes with enhanced expression in the procyclic stage, (ii) one augmented gene in the metacyclic stage, and (iii) one procyclic-exclusive transcript. Western blot analysis revealed that an antibody against a consensus-conserved peptide reacted with multiple calpain-like proteins, which is consistent with the multi-gene family characteristic. Flow cytometry and immunocytochemistry analyses revealed the presence of calpain-like molecules mainly in the cytoplasm, to a lesser extent in the plasma membrane, and negligible levels in the nucleus, which are all consistent with calpain localisation. Eventually, the calpain inhibitor MDL28170 was used for functional studies revealing (i) a leishmaniostatic effect, (ii) a reduction in the association index in mouse macrophages, (iii) ultra-structural alterations conceivable with autophagy, and (iv) an enhanced expression of the virulence factor GP63. CONCLUSION This report adds novel insights into the domain structure, expression, and localisation of L. braziliensis calpain-like molecules.

Clinical and Pathological Heterogeneity of Korean Patients with CAPN3 Mutations

PURPOSE: This study was designed to investigate the characteristics of Korean patients with calpainopathy. MATERIALS AND METHODS: Thirteen patients from ten unrelated families were diagnosed with calpainopathy via direct or targeted sequencing of the CAPN3 gene. Clinical, mutational, and pathological spectra were then analyzed. RESULTS: Nine different mutations, including four novel mutations (NM_000070: c.1524+1G>T, c.1789_1790inA, c.2184+1G>T, and c.2384C>T) were identified. The median age at symptom onset was 22 (interquartile range: 15-28). Common clinical findings were joint contracture in nine patients, winged scapula in four, and lordosis in one. However, we also found highly variable clinical features including early onset joint contractures, asymptomatic hyperCKemia, and heterogeneous clinical severity in three members of the same family. Four of nine muscle specimens revealed lobulated fibers, but three showed normal skeletal muscle histology. CONCLUSION: We identified four novel CAPN3 mutations and demonstrated clinical and pathological heterogeneity in Korean patients with calpainopathy.

Meat tenderness genetic polymorphisms occurrence and distribution in five Zebu breeds in Mexico

Background The Zebu cattle are represented by a diverse group of breeds in México. Traditionally these breeds have been associated with the tough beef characteristic. Validated genetic markers have the potential to be included in marker-assisted selection and management programs in order to improve traits such as beef tenderness. The incidence and distribution of Calpain and Calpastatin polymorphisms strongly associated with beef tenderness were estimated in registered cattle of five Zebu breeds in Mexico. Results A low and in some cases null frequency of favorable C allele of CAPN316 was determined in all breeds. Conversely, a more equilibrated frequency in CAPN4751 and CAST loci was observed. Conclusions Although the relatively low occurrence of favorable alleles in assessed loci may limit their use in selection programs, genotyping availability might be a practical and comprehensive tool for introgression programs by marker assisted selection and management as to improve meat tenderness of Zebu breeds.

Potential Interaction of Plasmodium falciparum Hsp60 and Calpain

After invasion of red blood cells, malaria matures within the cell by degrading hemoglobin avidly. For enormous protein breakdown in trophozoite stage, many efficient and ordered proteolysis networks have been postulated and exploited. In this study, a potential interaction of a 60-kDa Plasmodium falciparum (Pf)-heat shock protein (Hsp60) and Pf-calpain, a cysteine protease, was explored. Pf-infected RBC was isolated and the endogenous Pf-Hsp60 and Pf-calpain were determined by western blot analysis and similar antigenicity of GroEL and Pf-Hsp60 was determined with anti-Pf-Hsp60. Potential interaction of Pf-calpain and Pf-Hsp60 was determined by immunoprecipitation and immunofluorescence assay. Mizoribine, a well-known inhibitor of Hsp60, attenuated both Pf-calpain enzyme activity as well as P. falciparum growth. The presented data suggest that the Pf-Hsp60 may function on Pf-calpain in a part of networks during malaria growth.

Variant in CAPN10 gene and environmental factors show evidence of association with excess weight among young people in a Colombian population / Una variante del gen CAPN10 y los factores ambientales muestran asociación con el exceso de peso en jóvenes colombianos.

Introduction : Obesity results from interaction between genetic and environmental risk factors. Objective: To evaluate the effect of three gene variants and environmental factors on obesity and overweight in young people aged 10 to 18 years in a Colombian population. Materials and methods: A total of 424 subjects were selected and separated into three groups for a cross-sectional study; 100 obese and 112 overweight subjects were matched with 212 normal-weight controls. Associations were evaluated between excess weight and three genetic polymorphisms ( UCP3- rs1800849, FTO -rs17817449, and CAPN10 -rs3842570), as well as the family history, the time spent watching television and playing video games, and the diet. Results: A family history of obesity, the time spent watching television and playing video games, the lack of breastfeeding, a low consumption of cereals, legumes, fruits, vegetables, and a high consumption of fast foods were characteristics typically found in obese individuals compared to controls. A significant association between genotype I/I (SNP19 of CAPN10 ) and excess weight was found even with an active lifestyle. In addition, significant associations between the C/C genotype of the UCP3 gene and the G/G and T/T genotypes of the FTO gene and excess weight were found only in young sedentary individuals. Conclusions: In this population, inadequate diet and sedentary lifestyle increased the risk of excess weight. Genotype I/I of SNP19 in CAPN10 was significantly associated with excess weight. In contrast, FTO and UCP3 variants exhibited effects only in sedentary environments.

Introducción. La obesidad resulta de la interacción entre factores de riesgo genéticos y ambientales. Objetivo. Evaluar el efecto de tres variantes genéticas y factores ambientales en el exceso de peso en jóvenes de 10 a 18 años de Medellín, Colombia. Materiales y métodos. Se hizo un estudio transversal en 424 jóvenes divididos en tres grupos: 100 obesos, 112 jóvenes con sobrepeso, y, pareados con ellos, 212 jóvenes con peso adecuado, que conformaron el grupo de control. Se evaluó la asociación entre tres polimorfismos genéticos ( UCP3 -rs1800849, FTO -rs17817449 y CAPN10 -rs3842570) y el exceso de peso, así como su interacción con antecedentes familiares de enfermedad, el tiempo dedicado a ver televisión y a jugar videojuegos y el consumo de alimentos. Resultados. Los antecedentes familiares de obesidad, la dedicación de más de dos horas al día a ver televisión y jugar videojuegos, la falta de lactancia materna, el bajo consumo de cereales, legumbres, frutas y verduras y el gran consumo de comidas rápidas fueron más frecuentes entre los obesos que en los controles. Se observó una asociación significativa entre el genotipo I/I (SNP19 del CAPN10 ) y el exceso de peso, incluso en los jóvenes que llevaban una vida activa. Además, se encontró una asociación significativa entre los genotipos C/C del UCP3 y G/G y T/T del FTO y el exceso de peso, pero solo en los jóvenes sedentarios. Conclusiones. En esta población, la alimentación inadecuada y el sedentarismo aumentaron el riesgo de exceso de peso. El genotipo I/I de SNP19 del CAPN10 se asoció significativamente con el exceso de peso. Algunas variantes del FTO y el UCP3 mostraron tener efecto solo en jóvenes sedentarios.

Degradation of the Transcription Factors NF-kappaB, STAT3, and STAT5 Is Involved in Entamoeba histolytica-Induced Cell Death in Caco-2 Colonic Epithelial Cells

Entamoeba histolytica is a tissue-invasive protozoan parasite causing dysentery in humans. During infection of colonic tissues, amoebic trophozoites are able to kill host cells via apoptosis or necrosis, both of which trigger IL-8-mediated acute inflammatory responses. However, the signaling pathways involved in host cell death induced by E. histolytica have not yet been fully defined. In this study, we examined whether calpain plays a role in the cleavage of pro-survival transcription factors during cell death of colonic epithelial cells, induced by live E. histolytica trophozoites. Incubation with amoebic trophozoites induced activation of m-calpain in a time- and dose-dependent manner. Moreover, incubation with amoebae resulted in marked degradation of STAT proteins (STAT3 and STAT5) and NF-kappaB (p65) in Caco-2 cells. However, IkappaB, an inhibitor of NF-kappaB, was not cleaved in Caco-2 cells following adherence of E. histolytica. Entamoeba-induced cleavage of STAT proteins and NF-kappaB was partially inhibited by pretreatment of cells with a cell-permeable calpain inhibitor, calpeptin. In contrast, E. histolytica did not induce cleavage of caspase-3 in Caco-2 cells. Furthermore, pretreatment of Caco-2 cells with a calpain inhibitor, calpeptin (but not the pan-caspase inhibitor, z-VAD-fmk) or m-calpain siRNA partially reduced Entamoeba-induced DNA fragmentation in Caco-2 cells. These results suggest that calpain plays an important role in E. histolytica-induced degradation of NF-kappaB and STATs in colonic epithelial cells, which ultimately accelerates cell death.

Polimorfismo SNP-43 del gen de calpaína-10 en individuos con enfermedad coronaria y controles / SNP43 polymorphism of Calpain-10 gene in Southern Chilean subjects with coronary artery disease and controls

Resumen: La Diabetes mellitus tipo 2 (DMT2) es un reconocido factor de riesgo cardiovascular que ha mostrado asociación con aterosclerosis subclínica; lo cual podría ser explicado por la presencia de una base genética común entre ambas patologías. Varios polimorfismos del gen de calpaína-10 (CAPNIO) han sido asociados con insulino resistencia y DMT2, sin embargo, existe escasa evidencia de su relación con enfermedad coronaria. El objetivo del presente estudio fue evaluar la posible asociación de la variante SNP-43 de CAPNIO con el desarrollo de enfermedad coronaria en individuos del sur de Chile. Métodos: Fueron incluidos en este estudio, 218 pacientes adultos no relacionados con enfermedad arterial coronaria (EAC) confirmada mediante angiografía (estenosis >70 por ciento) y 194 individuos controles. La variante genética UCSNP-43 fue estudiada por PCR-RFLP. Resultados: No se observaron diferencias significativas entre las frecuencias genotípicas de la variante UCSNP-43 en pacientes con EAC (GG: 51.4 por ciento; GA: 42.7 por ciento; AA: 5.9 por ciento) y controles (GG: 59.6 por ciento; GA: 35.1 por ciento; AA: 5.2 por ciento, p=0.228). Similarmente, no hubo diferencias significativas entre las frecuencias alélicas entre pacientes con EAC y controles (p=0.200). La Odds Ratio fue de 1.17 (I.C 95 por ciento: 0.50-2.72), confirmando la ausencia reasociación. Conclusión: Nuestros datos sugieren que la variante UCSNP-43 del gen CAPNIO no está asociada a la presencia de enfermedad arterial coronaria en la población investigada.

Background: Diabetes mellitus type 2 (DMT2) is a well know cardiovascular risk factor and has been related to subclinic atherosclerosis, which might be explained by the presence of a common genetic basis in both diseases. Several polymorphisms of the cal-pain-10 gene (CAPNIO) have been associated with insulin resistance and DMT; nevertheless, there is insufficient evidence about their relation with coronary artery disease (CAD). Thus, in the present study we investigated the possible association between the SNP-43 variant of CAPNIO and the presence of CAD in Chilean subjects. Methods: A total of 218 unrelated patients with diagnosis of CAD confirmed by angiography (33-74 years old) and 194 healthy controls (30 - 68 years old) were included in this study. The SNP43 variant of the CAPNIO gene was evaluated by PCR-RFLP. Results: The genotype distribution for SNP43 variant of CAPNIO gene in CAD patients (GG: 51.4 percent; GA: 42.7 percent; AA: 5.9 percent) and controls (GG: 59.6 percent; GA: 35.1 percent; AA: 5.2 percent) was similar (P=0.228). Similarly, the allelic frequency was no different (P = 0.200). The OR for CAD related to AA homozygous genotype was 1.17 (95 percent C.I. = 0.50 - 2.72), confirming the absence of association. Conclusion: These findings suggest that the SNP43 polymorphism of the CAPNIO gene is not associated to CAD in the studied individuals.

The association of CAPN1 316 marker genotypes with growth and meat quality traits of steers finished on pasture

The objective of this paper was to determine the association of a SNP in the µ-calpain gene at position 316 with growth and quality of meat traits of steers grown on pasture. Fifty-nine Brangus and 20 Angus steers were genotyped for CAPN1 316. Warner Bratzler shear force was measured in l. lumborum samples after a 7-day aging period. A multivariate analysis of variance was performed, including shear force (WBSF), final weight (FW), average daily gain (ADG), backfat thickness (BFT), average monthly fat thickness gain (AMFTG), rib-eye area (REA), and beef rib-eye depth (RED) as dependent variables. The CAPN1 316 genotype was statistically significant. Univariate analyses were done with these variables. The marker genotype was statistically significant (p < 0.05) for WBSF (kg: CC: 4.41 ± 0.57; CG: 5.58 ± 0.20; GG: 6.29 ± 0.18), FW (kg: CC: 360.23 ± 14.71; CG: 381.34 ± 5.26; GG: 399.23 ± 4.68), and ADG (kg/d: CC: 0.675 ± 0.046; CG: 0.705 ± 0.016; GG: 0.765 ± 0.014) Shear force, final weight and average daily gain were significantly different according to the CAPN1 316 marker genotypes. The marker genotype was statistically significant in the multivariate analysis (p = 0.001). The first characteristic root explained 89 percent of the differences among genotypes. WBSF, FW and ADG were the most important traits in the first vector, indicating that animals with the marker genotype for lowest WBSF also have the lowest FW and ADG.

Trypanosoma cruzi: a stage-specific calpain-like protein is induced after various kinds of stress

Calpains are calcium-dependent cysteine proteinases found in all living organisms and are involved in diverse cellular processes. Calpain-like proteins have been reported after in silico analysis of the Tritryps genome and are believed to play important roles in cell functions of trypanosomatids. We describe the characterization of a member of this family, which is differentially expressed during the life-cycle of Trypanosoma cruzi.

Mutations of CAPN3 in Korean Patients with Limb-Girdle Muscular Dystrophy

The limb-girdle muscular dystrophy type 2A (LGMD2A) is a recessively inherited disease caused by a mutation of the calpain 3 gene (CAPN3), and is considered one of the most prevalent subtypes of limb-girdle muscular dystrophy (LGMD). In this study, we aimed to identify CAPN3 mutations and to characterize the phenotype of Korean patients with LGMD2A. Among 35 patients with LGMD, four patients, who showed calpain 3 deficiency on western blot analysis, were analyzed in this study. Total RNA extracted from frozen muscle tissue was amplified by reverse transcriptase polymerase chain reaction (RT-PCR) using six primer pairs covering all coding sequences of CAPN3, and direct sequencing was performed. Clinical and pathological features of the patients were also reviewed. We found four different mutations in five alleles from three patients. Of the pathogenic mutations identified, two were novel (c.2125T>C and c.2355-2357delTTC), and the others had been reported elsewhere (c.440G>C, c.1076C>T). All patients showed a high CK level with predominant proximal leg weakness, and the onset was in their childhood except for one patient. Among two novel CAPN3 mutations, one was a missense mutation (c.2125T>C [p.709Ser>Pro]), and the other was a small in-frame deletion causing omission of a single amino acid (c.2355-2357delTTC [p.786delPhe]). The clinical features of our patients were generally compatible with the characteristics of LGMD2A patients described in the previous studies.

Variación y distribución genética de los SNP's 19, 43 y 63 del gen de susceptibilidad de diabetes tipo 2 Calpaina 10 (Capn10) en la población peruana / Variation and genetic distribution of SNP's 19, 43 y 63 of the susceptibility gene calpain 10 (Capn10) for the type 2 diabetes in the peruvian population

La diabetes tipo 2 es una enfermedad compleja que tiene un componente genético. Calpaina 10 (CAPN10) es un gen de susceptibilidad para este gen y está localizado en 2q37.3. Pacientes de algunas poblaciones de origen amerindio presentan las frecuencias alélicas de los SNP19, 43 y 63 del gen CAPN10, que sugiere una relación causal entre este gen y la biabetes tipo 2. El origen filogenético común, nos permite suponer que CAPN10 también sería un gen de susceptibilidad en la población peruana nativa y mestiza, lo cual nos motivó a investigar esta relación en nuestra población. Se obtuvieron resultados de la frecuencia alélica de los SNP19, 43 y 63 de CAPN10 en 129 controles normales de Lima, la mayoría de origen mestizo. Además de la prueba del equilibrio de Hardy-Weinberg (H-W) para determinar si la población tiene una distribución genéticamente homogénea en dichos marcadores. Se puede concluir que la prueba de H-W sugiere fuertemente que nuestra población control es adecuada para un estudio de asociación y desequilibrio de ligamiento en pruebas caso-control. Esto a su vez es la base para futuros estudios de asociación y desequilibrio de ligamiento, postulando a CAPN10 como gen de susceptibilidad de diabetes tipo 2 en la población peruana.

Type 2 diabetes is a complex genetic disorder, where the gene calpain 10 (CAPN10) located in 2q37.3, plays an important role. Allele frequencies of SNP19, 43 and 63 are present in affected Amerindian populations and might suggest a possible relationship between CAPN10 and type 2 diabetes. The fact that Amerindian populations has a common phyllogenetic origin was our main motivation for studying this possible relation, because it would suggest' that CAPN10 is a susceptibility gene for native and admixed Peruvian populations. Allelic frequencies of SNP19, 43 and 63 of calpain 10 was obtained of 129 normal controls from Lima, most of them admixed population. Hardy-Weinberg test (H-W) was used in order to determine if the population had a genetically homogenous distribution for the employed molecular markers. It can be concluded that the H-W test strongly suggests that the control population is adequate for an association and linkage disequilibrium in case-control studies. Furthermore, this would mean be thstart of future association and linkage disequilibrium studies where CAPN10 would be considered as a susceptibility gene for type 2 diabetes in Peruvian population.

Relationship between calpain-10 gene polymorphism and insulin resistance phenotypes in Chinese / 华中科技大学学报（医学）（英德文版）

In order to determine whether the variations in the calpain-10 gene constitutes risk of type 2 diabetes (T2DM) in Chinese, the frequency of UCSNP-43, 44 in 268 adults newly diagnosed with T2DM (according to the 1999 ADA criteria) and 153 non-diabetic control subjects was investigated. For all subjects, the height, weight, waist-to-hip ratio (W/H) and blood pressure, as well as following parameters were measured: (1) 75-g oral glucose tolerance test with insulin, C-peptide, HbA1c and blood lipid profiles; (2) Genomic DNA extracted from peripheral blood lymphocytes was genotyped for UCSNP-43 (calpain-10-g. 4852 G/A) and UCSNP-44 (calpain-10-g. 4841 T/C) by sequencing a polymerase chain reaction (PCR)-amplified fragment. PCR product was selected by single strand conformation polymorphism (SSCP) and then sequenced. The results showed that there was significant difference between T2DM group and normal control group in allele frequencies, haplotype frequencies, or haplotype combinations of UCSNP-43 and -44 either. But in newly diagnosed T2DM group, it was found that the individuals with the genotype UCSNP-44 T/C + C/C had significantly increased fasting and post-challenge insulin levels (Fins and P2hIns), consistent with reduced insulin sensitivity. In the BMI> 25 subgroup, the differences were even more significant. It was demonstrated that the Calpain-10 gene polymorphism UCSNP-44 was associated with insulin sensitivity and Fins and P2hIns in newly diagnosed T2DM, although Calpain-10 doesn't appear as a major diabetes susceptible gene in this population.

Deletion analysis & calpain status for carrier detection in a family with Duchenne muscular dystrophy.

Eight females with a family history of Duchenne muscular dystrophy (DMD) were analysed for their carrier status by m-calpain test, which monitors the m-calpain (milli-calpain), a proteolytic enzyme in the platelets, using an ELISA technique. Four of the eight females were identified as carriers by virtue of their elevated enzyme levels as compared to control. DNA samples of these members were analysed to ascertain the carrier status, by PCR followed by dosage analysis by densitometry. DNA analysis confirmed the findings by calpain test, which underlines the reliability of this phenotypic test for carrier detection in DMD. Calpain test has been informative in a large group of patients and carriers tested so far. Since the calpain test is cost and labour effective, it is suited for routine and widespread screening purposes.