Elevated CpG island methylation of GCK gene predicts the risk of type 2 diabetes in Chinese males

Background

The GCK gene encodes hexokinase 4, which catalyzes the first step in most glucose metabolism pathways. The purpose of our study is to assess the contribution of GCK methylation to type 2 diabetes (T2D).

Methods and results

GCK methylation was evaluated in 48 T2D cases and 48 age- and gender-matched controls using the bisulphite pyrosequencing technology. Among the four CpG sites in the methylation assay, CpG4 and the other three CpGs (CpG1-3) were not in high correlation (r < 0.5). Significantly elevated methylation levels of GCK CpG4 methylation were observed in T2D patients than in the healthy controls (P = 0.004). A breakdown analysis by gender indicated that the association between CpG4 methylation and T2D was specific to males (P = 0.002). It is intriguing that another significant male-specific association was also found between GCK CpG4 methylation and total cholesterol (TC) concentration (r = 0.304, P = 0.036).

Conclusion

Our results showed that elevated GCK CpG4 methylation might suggest a risk of T2D in Chinese males. Gender disparity in GCK CpG4 methylation might provide a clue to elaborate the pathogenesis of T2D.     

Efecto de un programa de ejercicios fisioterapéuticos sobre el desempeño físico en adultos mayores institucionalizados

Objective

To evaluate changes in physical performance in institutionalized older adults through a program of physiotherapy exercises.

Materials and methods

A quasi-experimental study was conducted on adults over 60 years-old, institutionalized in Lima, Peru. The exercise program was implemented in 45 minutes sessions included warming-up, muscle strengthening exercises, balance, gait training and cooling phase, three times a week for 12 weeks. Physical performance was measured with the Short Physical Performance Battery (SPPB) one week before and after the intervention. It included 45 participants, of whom 16 did not attend any of the sessions and was used as a control group.

Results

The mean age was 77.6 ± 7.1 years, and 62.2% were women. The mean baseline SPPB was 7.0 ± 1.6 in the intervention group, and 6.9 ± 1.9 in the control group (P=.90). A change of 2.6 ± 1.8 was observed in the SPPB of the intervention group versus -1.4 ± 2.0 in the control group (P<.001).

Conclusions

The development of a physiotherapy exercise program for institutionalized elderly increases physical performance, which could be implemented in care centers for elderly.     

The treatment of paravertebral malignant mesenchymal tumor pain with cryoablation

Objective

The purpose of this study was to evaluate the feasibility, safety, and efficacy of cryoablation to treat pain from paravertebral malignant mesenchymal tumors.

Method

Cryoablation was performed on 15 patients who suffer from unresectable painful paravertebral malignant mesenchymal tumors and whose pain was poorly controlled by conventional treatment methods. The sizes of the tumors varied from 3 to 20 cm. The patients’ pain at baseline before the cryoablation and the pain they felt 1 day, 1 week, 1 month, and 3 months after the cryoablation were assessed respectively by the Brief Pain Inventory (BPI).

Result

BPI scores are divided into two categories: the influence of pain and the severity of pain. Both results showed a decline after the cryoablation. The evaluation score of pain severity decreased significantly (P = 0.001, P = 0.031) on the observation of 1 day and 1 month after the cryoablation; that of pain influence decreased significantly (P = 0.016, P = 0.036) in the cases of 1 day and 1 week after cryoablation. Two patients (13.33%) had mild complications, but no serious complications occurred.

Conclusion

Cryoablation is a low risk, well-tolerated topical treatment for the pain of patients with unresectable paravertebral malignant mesenchymal tumor.     

Efectos del ejercicio físico en la funcionalidad y calidad de vida en mayores institucionalizados diagnosticados de gonartrosis

Introduction

At present, aging and increased life expectancy implies a greater susceptibility to dependence, which then leads to the irreversible loss of quality of life, in many cases due to chronic diseases such as osteoarthritis (OA). The aim of this study was to determine the effect of a treatment based on aerobic exercise in institutionalised elderly people diagnosed with knee osteoarthritis.

Material and method

An experimental, prospective, single blind study was conducted. The sample (n = 31), was divided into two groups. The experimental group (n = 17) was treated based on aerobic exercise for 4 weeks with 2 sessions per week and each lasting 50 minutes. We conducted a pre-test and post-test assessment using a visual analogue scale, WOMAC questionnaire and SF-36 as measuring instruments. The statistical program SPSS15.0 was used for the analysis of the data.

Results

We obtained significant differences in the t-test for paired samples in the three dimensions of the WOMAC questionnaire, P<.001, in the perceived pain P<.001 and in the physical function, vitality and mental health dimensions of the SF-36 with a 95% confidence interval.

Conclusion

Exercise gave positive results in functional (pain, stiffness, physical function) and psychological aspects (mental health and vitality) in the institutionalised elderly.     

Valoración de la fuerza,la flexibilidad,el equilibrio,la resistencia y la agilidad en función del índice de masa corporal en mujeres mayores activas

Introduction

Overweight and obesity are increasing at an alarming rate among older people. This is mainly because this population is predominantly sedentary. The aim of this study was to classify, according to the body mass index (BMI), a group of older active women and to evaluate the different basic physical abilities as a function of this.

Material and methods

The BMI and fitness were evaluated in 60 elderly active women (mean age: 66.14 ± 6.59 years) using the 2-minute step test, arm curl test, chair stand test, back scratch test, chair-sit and reach-test, flamenco test, and 8-foot up-and-go test.

Results

It was found that 52.23% of the women studied had a normal BMI and 47.76% were slightly overweight. There were no cases of obesity or underweight. Women with normal BMI had better values in all tests than overweight women. Significant differences were found in the flamenco test (P < .05), and 8-foot up-and-go test (P < .01).

Conclusions

Older women who usually do physical activity had a normal or slightly overweight BMI. It was also found that women with lower BMI have better resistance, flexibility, balance and strength.     

Evaluación del sufrimiento en la demencia avanzada

Introduction

At the end stage of life of dementia, medical comorbidities are associated with a high degree of patient suffering. The aim of this study was to assess the relationship between the lack of symptoms of discomfort and the level of patient suffering. The relationship with psychological distress and caregiver burden was also clarified.

Material and methods

This study included patients with advanced dementia according to the criteria of the Hospice Enrolment Criteria for End-stage Dementia patients. Patient suffering was assessed with Mini-Suffering State Examination (MSSE). The caregivers were scored by Zarit caregiver burden scale (ZR), and the General Health Questionnaire of Goldberg (GHQ-28). Central tendency and correlation tests were used in the statistical analysis.

Results

The study recorded data from 71 patients. In the comorbidity of medical symptoms associated with advanced dementia, pneumonia (Spearman's rho: −0.29; P=.01), and malnutrition (Spearman's rho: −0.25; P=.03), showed a significant association with the total scale score of MSSE. There were no significant correlations between patient suffering and caregiver psychological distress (r: 0.11; P=.37), or caregiver burden (r: 0.13; P=.32).

Conclusions

The identification of suffering in patients with advanced dementia is recognised by specific symptoms, such as pneumonia and malnutrition. The caregiver’ psychological distress of the caregiver was shown to be unrelated to patient suffering as measured by MSSE.     

The MTMR9 rs2293855 polymorphism is associated with glucose tolerance,insulin secretion,insulin sensitivity and increased risk of prediabetes

Background

Polymorphism of rs2293855 in gene MTMR9 has been associated with obesity and metabolic syndrome. We aim to study the association of rs2293855 with type 2 diabetes mellitus (T2DM) intermediate phenotypes in a Han Chinese population.

Methods

The polymorphism was genotyped in 838 Han Chinese individuals using Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS); all participants underwent a 75 g oral glucose tolerance test (OGTT); associations between the polymorphism and glucose tolerance, indices of insulin secretion and indices of insulin sensitivity were analyzed.

Results

The frequency of genotypes and alleles differed significantly between normal glucose tolerance and prediabetes (P = 0.043 and P = 0.009, respectively). The GG homozygous presented higher fasting plasma glucose (P = 0.009), higher 2-hour plasma glucose (P = 0.024) and higher glucose area under the curve (AUC, P = 0.01). Moreover, the G allele of rs2293855 was associated with glucose intolerance (fasting glucose, P = 0.012; glucose AUC, P = 0.006; 2-h glucose, P = 0.024); it is also associated with decreased indices of insulin sensitivity (fasting insulin, P = 0.043; insulin sensitivity index composite, P = 0.009; homeostasis model assessment of insulin resistance, HOMA-IR, P = 0.008) and decreased indices of insulin secretion (HOMA of beta cell function, HOMA-B, P = 0.028; insulinogenic index, P = 0.003). In addition, the minor allele G was also associated with increased risk of prediabetes (OR = 1.463, 95%CI: 1.066–2.009, P = 0.018).

Conclusions

Polymorphism of rs2293855 in MTMR9 is associated with measures of glucose tolerance, indices of insulin secretion and indices of insulin sensitivity. We also suggest that allele G is likely to increase the risk of prediabetes by influencing both insulin secretion and insulin sensitivity.     

Body composition in patients with classical homocystinuria: body mass relates to homocysteine and choline metabolism

Introduction

Classical homocystinuria is a rare genetic disease caused by cystathionine β-synthase deficiency, resulting in homocysteine accumulation. Growing evidence suggests that reduced fat mass in patients with classical homocystinuria may be associated with alterations in choline and homocysteine pathways. This study aimed to evaluate the body composition of patients with classical homocystinuria, identifying changes in body fat percentage and correlating findings with biochemical markers of homocysteine and choline pathways, lipoprotein levels and bone mineral density (BMD) T-scores.

Methods

Nine patients with classical homocystinuria were included in the study. Levels of homocysteine, methionine, cysteine, choline, betaine, dimethylglycine and ethanolamine were determined. Body composition was assessed by bioelectrical impedance analysis (BIA) in patients and in 18 controls. Data on the last BMD measurement and lipoprotein profile were obtained from medical records.

Results

Of 9 patients, 4 (44%) had a low body fat percentage, but no statistically significant differences were found between patients and controls. Homocysteine and methionine levels were negatively correlated with body mass index (BMI), while cysteine showed a positive correlation with BMI (p < 0.05). There was a trend between total choline levels and body fat percentage (r = 0.439, p = 0.07). HDL cholesterol correlated with choline and ethanolamine levels (r = 0.757, p = 0.049; r = 0.847, p = 0.016, respectively), and total cholesterol also correlated with choline levels (r = 0.775, p = 0.041). There was no association between BMD T-scores and body composition.

Conclusions

These results suggest that reduced fat mass is common in patients with classical homocystinuria, and that alterations in homocysteine and choline pathways affect body mass and lipid metabolism.     

Association of heat shock protein70-2 (HSP70-2) gene polymorphism with coronary artery disease in an Iranian population

Background

Coronary artery disease (CAD) is an inflammatory process and a major cause of mortality and morbidity. The (heat shock protein70-2) HSP70-2 gene is reported to be associated with coronary artery disease possibly by affecting the regulation of pro-inflammatory cytokines such as TNF-α. The association between CAD and the HSP70-2 gene + 1267A>G polymorphism has been studied in some populations but there are no data about this association in the Iranian population.

Aim

We have investigated the association between the HSP70-2 gene + 1267A>G polymorphism and angiographically defined CAD within an Iranian population.

Methods

We determined the presence of the HSP70-2 gene + 1267A>G polymorphism in 628 patients with CAD and 307 healthy individuals using PCR-RFLP. Of the patients, 433 (68%) had > 50% stenosis (CAD +) and the remaining 195 patients had < 50% stenosis (CAD −), based on coronary angiography. Angiogram positive patients were subdivided into three groups: those with single (n = 113), double (n = 134), and triple vessels (n = 186) disease.

Results

A significant higher frequency of AG + GG genotypes (G allele carriers) was observed in angiogram positive and angiogram negative groups compared to controls in a dominant analysis model of the HSP70-2 gene + 1267A>G position (51.2 vs. 43.2, P = 0.002, OR = 1.37) (51.0 vs. 43.2, P = 0.01, OR = 1.37). The allele frequency of the HSP70-2 G was also significantly higher in angiogram positive and angiogram negative groups compared to the control group (51.2 vs. 43.2, P = 0.002, OR = 1.37) (51.0 vs. 43.2, P = 0.01, OR = 1.37).

Conclusion

These results suggest that HSP70-2 + 1267 polymorphism may influence the risk of CAD in Iranian population, however further studies are needed to clarify the role of other HSP70-2 gene polymorphisms in the pathogenesis of the CAD.     

Enfermedad crónica,mortalidad, discapacidad y pérdida de movilidad en ancianos españoles: estudio FRADEA

Introduction

The objective of this study was to analyse the relationships between the major chronic diseases and multiple morbidity, with mortality, incident disability in basic activities of daily living, and loss of mobility in the elderly.

Material and methods

A total of 943 participants were selected from the FRADEA Study, using available baseline data of chronic diseases, and at the follow-up visit of mortality, incident disability, and loss of mobility. The analysis was made of the unadjusted and adjusted association between the number of chronic diseases, the number of 14 pre-selected diseases, and the presence of two or more chronic diseases (multiple morbidity) with adverse health events recorded.

Results

Participants with a higher number of diseases (OR 1.11; 95% CI: 1.02-1.22), and 14 pre-selected diseases (OR 1.19; 95% CI: 1.03-1.38) had a higher adjusted mortality risk, but not a higher incident disease or mobility loss risk. Subjects with multiple morbidity had a higher non-significant mortality risk (HR 1.45; 95% CI: 0.87-2.43), than those without multiple morbidity. Disability-free mean time in participants with and without multiple morbidity was 846 ± 34 and 731 ± 17 days, respectively (Log-rank χ² 7.45. P =.006), and with our without mobility loss was 818±32 and 696±13 days, respectively (Log rank χ² 10.99. P =.001).

Conclusions

Multiple morbidity was not associated with mortality, incident disability in ADL, or mobility loss in adults older than 70 years, although if mortality is taken into account, the number of chronic diseases is linear.     

Relationship between CCR2-V64I polymorphism and cancer risk: A meta-analysis

Background and objectives

The role of CCR2-V64I polymorphism in various cancers has been reported in many studies. However, results from published studies on the association between CCR2-V64I polymorphism and cancer risk are conflicting. Therefore, we performed a meta-analysis to estimate the overall cancer risk associated with the polymorphism.

Methods

Electronic searches of PubMed and EMBASE were conducted for all publications on the association between this variant and cancer. Odds ratios (OR) with 95% confidence intervals (95% CI) were used to access the strength of this association.

Results

Sixteen studies with 2661 cancer patients and 5801 healthy controls were included. Overall, significant association was found between the CCR2-V64I polymorphism and cancer risk (OR = 1.84, 95% CI = 1.35–2.51, AA vs GA/GG, P = 0.37). In the subgroup analysis stratified by cancer types, there was a significant association between this polymorphism and bladder cancer (OR = 2.06, 95% CI = 1.02–4.15, AA vs GA/GG, P = 0.11), cervical cancer (OR = 3.34, 95% CI = 1.48–7.50, AA vs GG, P = 0.56), and oral cancer (OR = 2.04, 95% CI = 1.46–2.84, GA vs GG, P = 0.70). In the subgroup analysis stratified by ethnicities, an increased cancer risk was also found in Europeans (OR = 2.31, 95% CI = 1.45–3.68, AA vs GA/GG, P = 0.16) and Asians (OR = 1.88, 95% CI = 1.12–3.16, AA vs GA/GG, P = 0.92).

Conclusion

This meta-analysis suggested that CCR2-V64I polymorphism may contribute to an increased risk of cancer.     

Inmunosenescencia prematura en ratones triple-transgénicos para la enfermedad del Alzheimer

Introduction

A deterioration of the neuroimmunoendocrine network has been observed in Alzheimer's disease (AD). However, the peripheral immune response has hardly been investigated in this pathology. Since some immune function parameters have been established as good markers of the rate of ageing, and can predict longevity, the aim of the present work was to study some of these functions in splenic leucocytes in transgenic mice for AD of different ages.

Material and methods

Young female (4 ± 1 months), adult (9 ± 1 months), and mature (12 ± 1 months) triple-transgenic mice for AD (3 xTgAD) and non-transgenic (NTg) control mice of the same ages were used. The chemotaxis, the anti-tumour activity of «natural killer» (NK) cells and the lymphoproliferative response in the presence of the mitogens concanavalin A and lipopolysaccharide, functions that decrease with age, were determined in splenic leucocytes. In addition, the differences in lifespan between 3 xTgAD and NTg were studied in parallel using other animals, until their death through natural causes.

Results

In 3 xTgAD, with respect to NTg, chemotaxis decreased at all ages studied, whereas in lymphoproliferative response this reduction was shown at 4 months and 9 months. NK activity was diminished only in young 3 xTgAD with respect to NTg. The 3 xTgAD showed a shorter lifespan than the NTg control group.

Conclusions

The 3 xTgAD mice show a premature immunosenescence, which could explain their early mortality. The determination of these immune functions at peripheral level could serve as a marker of the progression of the Alzheimer's disease.     

Resiliencia en cuidadores de personas con demencia: estudio preliminar

Introduction

Caring for a relative with dementia often has negative effects on the caregive?s physical and psychological health. However, many caregivers successfully cope with the stress factors arising from care, and even have uplifts during their experience, showing high resilience levels. This study presents a preliminary analysis of resilience in caregivers of patients with dementia, exploring its relationship with different variables.

Material and methods

Resilience was assessed (by CD-RISC) in 53 family caregivers of patients with dementia. Resilience was correlated to the following variables: caregiving context, stressors (e.g., cognitive impairment), appraisals (e.g., burden), moderators (e.g., personality traits and resources), and caregiving consequences (physical and psychological health).

Results

The participants showed moderate scores on resilience. Resilience was associated with poor emotional and physical status (significant inverse correlations with anxiety, depression, psycho-active drug use, health habits…). High resilience scores were significantly correlated to burden, neuroticism and extraversion, self-efficacy, self-esteem and less use of emotion focused coping strategies.

Conclusions

Higher resilience relates to a good emotional and physical status in caregivers. Moreover, resilience is more associated with caregiver variables (e.g., appraisal and coping with care, personality features), than to situational variables. The data highlight the strengthening of these types of appraisal and coping as a way to improve caregivers’ resilience and, consequently, their health.     

Diastolic suction in heart failure: Impact of left ventricular geometry,untwist, and flow mechanics

Aims

Vector flow mapping (VFM) can be used to assess intraventricular hemodynamics quantitatively. This study assessed the magnitude of the suction flow kinetic energy with VFM and investigated the relation between left ventricular (LV) function and geometry in patients with an estimated elevated LV filling pressure.

Materials and methods

We studied 24 subjects with an elevated LV filling pressure (EFP group) and 36 normal subjects (normal group). Suction was defined as flow directed toward the apex during the period from soon after systolic ejection to before mitral inflow. The flow kinetic energy index was quantified as the sum of the product of the blood mass and velocity vector and its magnitude to the peak value was measured.

Key findings

Suction flow was observed in 12 (50%) EFP-group patients and 36 (100%) normal-group subjects. The magnitude of the suction kinetic energy index was significantly smaller in EFP versus normal group (2.7 ± 3.8 vs. 5.7 ± 4.4 g/s/cm², P < 0.01). The EFP-group patients with suction had a smaller LV end-systolic volume (ESV) (P < 0.01), greater ellipsoidal geometry (P < 0.05) and untwisting rate (P < 0.01) than the EFP-group patients without suction. A regression analysis indicated a significant linear relation between the suction kinetic energy index and LVEF (r = 0.43, P = 0.04), ESV (r = − 0.40, P = 0.05), eccentricity index (r = 0.44, P = 0.04), and untwisting rate (r = 0.51, P = 0.04).

Significance

The magnitude of the suction flow kinetic energy index derived from VFM may allow the quantitative assessment of the suction flow, which correlates with LV systolic function, geometry, and untwisting mechanics.     

The contribution of platelet glycoproteins (GPIa C807T and GPIba C-5T) and cyclooxygenase 2 (COX-2G-765C) polymorphisms to platelet response in patients treated with aspirin

Objective

Aspirin is an antiplatelet agent commonly used in treatment of patients with high risk to develop stroke and myocardial infarction. However, inter-individual variability regarding the inhibition of platelet function by aspirin is well documented. In this study, the correlation between platelet glycoproteins (GPIa C807T and GPIba C-5T) and cyclooxygenase 2 (COX-2G-765C) polymorphisms and antiplatelet response in patients treated with aspirin was investigated.

Methods

Jordanian adult patients (n = 584) who are taking aspirin as an antiplatelet agent participated in the study. Platelet aggregation response was measured using Multiplate Analyzer® system. Polymerase chain reaction–restriction fragment length polymorphism assay (PCR–RFLP) was used for genotyping of the examined polymorphisms.

Results

Aspirin resistance was found in 15.8% of patients. Response to aspirin was significantly associated with GPIba C-5T polymorphism (P < 0.05). However, the GPIa C807T and COX-2G-765C polymorphisms were not related to aspirin resistance (P > 0.05).

Conclusion

A considerable fraction of the Jordanian population is resistant to the antiplatelet effect of aspirin, which might be related to GPIba C-5T polymorphism.     

Cox-2 gene variants in migraine

Purpose

Migraine is a multifactorial and complex disorder, and any clear diagnostic marker to assess the status of the migraineurs has not been established, yet. Nonsteroidal anti-inflammatory drugs reduce production of prostanoids including PGE2 by inhibiting COX-1 and/or COX-2, and thereby suppress inflammatory pain in patients suffering from rheumatoid arthritis, osteoarthritis, and migraine. Thus, COX-2 regulation is important in the pathogenesis and treatment of migraine. We prospectively investigated COX-2-765G → C and COX-2-1195A → G gene polymorphisms which may account for an increased risk of migraine.

Methods

The present analyses are based on 144 case subjects with migraine disease and 123 non-case subjects. Genotyping of COX-2 gene polymorphisms (COX-2-765G → C, COX-2-1195A → G) was detected by PCR-RFLP.

Results

We, for the first time, demonstrated positive association of COX-2 gene variants with an increased risk for development of migraine. Carriers of COX-2-765 C + genotype in controls were higher than in the patients (57.7% and 36.1% respectively; P < 0.0001) and the frequencies of G + genotype in patients were higher than in the controls (97.9% and 88.6% respectively; P: 0.002). In addition, frequencies of COX-2-765 GG and GC genotypes in patients were higher than in the controls (P < 0.0001, P < 0.0001 respectively). It seems that COX-2-765 G + genotype had increased and COX-2-765 C + genotype had decreased risk for migraine. In COX-2-1195 polymorphism only AG genotype was statistically significantly different in patients than in the controls (P < 0.05).

Conclusions

Our findings have suggested that COX-2-765 G + genotype could facilitate the development of migraine disease.     

Forkhead-box-O1 locus y marcadores metabólicos en los ancianos: estudio de asociación

Introduction

Mutations of forkhead-box-O1 (FOXO1) gene at locus 13q14.1 cause changes in biochemical parameters leading to premature aging. Protein FoxO1 participates in the regulation of biochemical pathways, including those influencing the regulation of lipid profile and glucose metabolism. These parameters are a risk factor for all-cause mortality in the elderly population. The aim of this study was to investigate the relationship between FOXO1 locus and metabolic-nutritional markers.

Material and methods

Single-nucleotide polymorphisms (SNP) rs2721069, rs4943794 and rs7981045 were determined in 594 hospitalized elderly (65-99 years), patients consecutively admitted to a geriatric ward, and tested the association of FOXO1 variants with biological markers by the analyses of co-variance (ANCOVA) and by Genotype Score Model statistic.

Results

The ANCOVA analysis, under different genetic models, revealed significant associations. In particular, assuming a dominant genetic model, a significant association with serum levels of fasting glucose was observed for rs2721069 (P = .034) and rs4943794 (P = .012). For rs4943794 a significant association assuming a free genetic model (P = .039) and an additive one (P = .012) was also observed. No significant relationship was observed between rs7981045 and the analyzed markers. The Genotype Score Model analysis confirmed a significant association between FOXO1 SNP and fasting glucose, taking the SNP rs2721069 and rs4943794 together (P = .048; β = 3.198).

Conclusions

Aging is a complex process, resulting from the interaction between several factors, including environmental and genetic ones. Our findings suggest that FOXO1 locus may influence blood glucose levels in hospitalized older patients, thus being one of the genetic factors contributing to healthy aging.     

Novel distribution of calreticulin to cardiomyocyte mitochondria and its increase in a rat model of dilated cardiomyopathy

Background

Calreticulin (CRT), a Ca²⁺-binding chaperone of the endoplasmic reticulum, can also be found in several other locations including the cytosol, nucleus, secretory granules, the outer side of the plasma membrane, and the extracellular matrix. Whether CRT is localized at mitochondria of cardiomyocytes and whether such localization is affected under DCM are still unclear.

Methods and results

The DCM model was generated in rats by the daily oral administration of furazolidone for thirty weeks. Echocardiographic and hemodynamic studies demonstrated enlarged left ventricular dimensions and reduced systolic and diastolic function in DCM rats. Immuno-electron microscopy and Western blot showed that CRT was present in cardiomyocyte mitochondria and the mitochondrial content of CRT was increased in DCM hearts (P < 0.05). Morphometric analysis showed notable myocardial apoptosis and mitochondrial swelling with fractured or dissolved cristae in the DCM hearts. Compared with the control group, the mitochondrial membrane potential level of the freshly isolated cardiac mitochondria and the enzyme activities of cytochrome c oxidase and succinate dehydrogenase in the model group were significantly decreased (P < 0.05), and the myocardial apoptosis index and the caspase activities of caspase-9 and caspase-3 were significantly increased (P < 0.05). Pearson linear correlation analysis showed that the mitochondrial content of CRT had negative correlations with the mitochondrial function, and a positive correlation with myocardial apoptosis index (P < 0.001). The protein expression level of cytochrome c and the phosphorylation activity of STAT3 in the mitochondrial fraction were significantly decreased in the model group compared with the control group (P < 0.05).

Conclusions

These data demonstrate that CRT is localized at cardiomyocyte mitochondria and its mitochondrial content is increased in DCM hearts.