Ursodeoxycholic acid induces sarcopenia associated with decreased protein synthesis and autophagic flux

BACKGROUND: Skeletal muscle generates force and movements and maintains posture. Under pathological conditions, muscle fibers suffer an imbalance in protein synthesis/degradation. This event causes muscle mass loss and decreased strength and muscle function, a syndrome known as sarcopenia. Recently, our laboratory described secondary sarcopenia in a chronic cholestatic liver disease (CCLD) mouse model. Interestingly, the administration of ursodeoxycholic acid (UDCA), a hydrophilic bile acid, is an effective therapy for cholestatic hepatic alterations. However, the effect of UDCA on skeletal muscle mass and functionality has never been evaluated, nor the possible involved mechanisms. METHODS: We assessed the ability of UDCA to generate sarcopenia in C57BL6 mice and develop a sarcopenic-like phenotype in C2C12 myotubes and isolated muscle fibers. In mice, we measured muscle strength by a grip strength test, muscle mass by bioimpedance and mass for specific muscles, and physical function by a treadmill test. We also detected the fiber's diameter and content of sarcomeric proteins. In C2C12 myotubes and/or isolated muscle fibers, we determined the diameter and troponin I level to validate the cellular effect. Moreover, to evaluate possible mechanisms, we detected puromycin incorporation, p70S6K, and 4EBP1 to evaluate protein synthesis and ULK1, LC3 I, and II protein levels to determine autophagic flux. The mitophagosome-like structures were detected by transmission electron microscopy. RESULTS: UDCA induced sarcopenia in healthy mice, evidenced by decreased strength, muscle mass, and physical function, with a decline in the fiber's diameter and the troponin I protein levels. In the C2C12 myotubes, we observed that UDCA caused a reduction in the diameter and content of MHC, troponin I, puromycin incorporation, and phosphorylated forms of p70S6K and 4EBP1. Further, we detected increased levels of phosphorylated ULK1, the LC3II/LC3I ratio, and the number of mitophagosome-like structures. These data suggest that UDCA induces a sarcopenic-like phenotype with decreased protein synthesis and autophagic flux. CONCLUSIONS: Our results indicate that UDCA induces sarcopenia in mice and sarcopenic-like features in C2C12 myotubes and/or isolated muscle fibers concomitantly with decreased protein synthesis and alterations in autophagic flux.

Interleukin-6 contributes to myocardial damage in pregnant rats with reduced uterine perfusion pressure

Preeclampsia is one of the most frequent and difficult illnesses in pregnancy, which jeopardizes both mother and fetus. There are several diagnostic criteria for preeclampsia. However, the preeclampsia-associated myocardial damage has not been described. In this study, we employed reduced uterine perfusion pressure (RUPP) to generate a rat model of preeclampsia for the evaluation of myocardial damage in late-gestation rats. The expressions of cardiac injury markers were analyzed by immunohistochemistry and ELISA. The arterial pressure and myocardial tissue velocities were also measured. The role of interleukin (IL)-6 in RUPP-associated myocardial damage was further explored. The results showed that RUPP rats had significant myocardial damage, as demonstrated by the high expressions of myoglobin, creatine kinase isoenzyme, cardiac troponin I, and brain natriuretic peptide. In addition, RUPP increased the mean arterial pressure and the early transmitral flow velocity to mitral annulus early diastolic velocity ratio (E/Ea). Furthermore, IL-6 deteriorated these abnormalities, whereas inhibition of IL-6 significantly relieved them. In conclusion, our study demonstrated that RUPP rats displayed myocardial damage in an IL-6-dependent manner.

Asociación entre la obstrucción apendicular y el tipo morfológico de apendicitis aguda / Association between appendiceal obstruction and the morphological type of acute appendicitis

Objetivo: Determinar si el tipo morfológico de apendicitis está asociado con el tipo de obstrucción apendicular. Materiales y métodos: Se realizó un estudio descriptivo, observacional y prospectivo en el Hospital Belén de Trujillo, durante el año 2013. Resultados: Formaron parte del estudio 398 casos. El 54% de los pacientes tuvo entre 10 y 29 años. El 55,5% fueron de sexo masculino y el 44,5% de sexo femenino. La longitud promedio del apéndice fue 7,19 ± 1,6 y el diámetro 1,14 ± 0,5 cm. Los apéndices cecales con diámetro menor a 0,8 cm, no presentaron inflamación aguda. El 16,2% de los apéndices estuvieron perforados. En el 43% se evidencio una obstrucción en la luz apendicular, que en el 56,3% correspondió a la presencia de un bolo fecal, en un 29,9% a acodamiento del apéndice cecal y 4,8% a fecalito. En el 5,4% de los casos, el parásito encontrado fue E. vermicularis. El 81,4% de los apéndices que tenían un bolo fecal o un fecalito, presentaron apendicitis supurativa severa, gangrena y/o perforación mientras que sólo el 55,4% de los apéndices que tenían hiperplasia o acodamiento presentaron los tipos morfológicos más severos (p < 0,05). Conclusiones: Los apéndices que tuvieron un bolo fecal o un fecalito tuvieron un tipo morfológico de apendicitis más severo que los que tuvieron otro tipo de obstrucción. Por tanto, SÍ hubo una asociación estadísticamente significativa entre el tipo morfológico de apendicitis y el tipo de obstrucción.

Objective: Determine if the morphological type of appendicitis is associated with the type of appendiceal obstruction. Material and methods: A descriptive, observational and prospective study was conducted at the Hospital Belén of Trujillo, during the year 2013. Results: There were 398 cases that took part of the study. A 54% of patients had between 10 and 29 years old, 55.5% were males and 44.5% females. The average length of the appendix was 7.19 ± 1.6 and 1.14 ± 0.5 cm diameter. Cecal appendices with diameter less than 0.8 did not show acute inflammation. A 16.2% of the appendices were perforated. In 43% a obstruction was evident in the appendiceal lumen, which corresponded to 56.3% for the presence of fecal bolus, 29.9% to bend appendiceal and 4.8% to faecolith. In 5.4% of cases a parasite E.vermicularis was found. A 81.4% of the appendices that had a fecal bolus or faecolith, had severe suppurative appendicitis, gangrene and / or perforation while only 55.4% of the appendices that had hyperplasia or bending presented the most severe morphological types (p <0.05). Conclusions: The appendices that had a fecal bolus or a faecolith had a morphological type of appendicitis more severe than those who had other obstructions type. Therefore, there was a statistically significant association between the morphological type of appendicitis and the type of obstruction.

Pseudoinfarto agudo do miocárdio devido à síndrome da disfunção ventricular apical transitória (síndrome de Takotsubo) / Pseudo-acute myocardial infarction due to transient apical ventricular dysfunction syndrome (Takotsubo syndrome)

A síndrome de Takotsubo caracteriza-se por disfunção ventricular esquerda transitória, predominantemente medioapical, desencadeada caracteristicamente por estresse físico ou emocional. Relata-se aqui o caso de uma paciente de 61 anos de idade, admitida com tontura, sudorese profusa e mal-estar súbito, após intenso estresse emocional. Exame físico e eletrocardiograma inicial foram normais, porém havia elevação de troponina I e CKMB massa. Suspeitou-se de infarto agudo do miocárdio sem supradesnivelamento do segmento ST, indicando cineangiocoronariografia de urgência. Foram evidenciados ventrículo esquerdo com hipocinesia difusa grave, balonamento sistólico medioapical e coronárias sem lesões significativas. A paciente foi encaminhada aos cuidados intensivos, evoluindo satisfatoriamente com terapia de suporte. Conforme visto, a cardiomiopatia de Takotsubo pode simular infarto agudo do miocárdio, sendo a cineangiocoronariografia importante para distinção na fase aguda. Neste caso, a paciente evoluiu com resolução espontânea da disfunção ventricular, sem sequelas.

Takotsubo syndrome is characterized by predominantly medial-apical transient left ventricular dysfunction, which is typically triggered by physical or emotional stress. The present article reports the case of a 61-year-old female patient presenting with dizziness, excessive sweating, and sudden state of ill feeling following an episode involving intense emotional stress. The physical examination and electrocardiogram were normal upon admission, but the troponin I and creatine kinase-MB concentrations were increased. Acute myocardial infarction without ST segment elevation was suspected, and coronary angiography was immediately performed, which showed severe diffuse left ventricular hypokinesia, medial-apical systolic ballooning, and a lack of significant coronary injury. The patient was referred to the intensive care unit and was successfully treated with supportive therapy. As this case shows, Takotsubo syndrome might simulate the clinical manifestations of acute myocardial infarction, and coronary angiography is necessary to distinguish between both myocardial infarction and myocardial infarction in the acute stage. The present patient progressed with spontaneous resolution of the ventricular dysfunction without any sequelae.

TNNI3K is a novel mediator of myofilament function and phosphorylates cardiac troponin I

The phosphorylation of cardiac troponin I (cTnI) plays an important role in the contractile dysfunction associated with heart failure. Human cardiac troponin I-interacting kinase (TNNI3K) is a novel cardiac-specific functional kinase that can bind to cTnI in a yeast two-hybrid screen. The purpose of this study was to investigate whether TNNI3K can phosphorylate cTnI at specific sites and to examine whether the phosphorylation of cTnI caused by TNNI3K can regulate cardiac myofilament contractile function. Co-immunoprecipitation was performed to confirm that TNNI3K could interact with cTnI. Kinase assays further indicated that TNNI3K did not phosphorylate cTnI at Ser23/24 and Ser44, but directly phosphorylated Ser43 and Thr143 in vitro. The results obtained for adult rat cardiomyocytes also indicated that enhanced phosphorylation of cTnI at Ser43 and Thr143 correlated with rTNNI3K (rat TNNI3K) overexpression, and phosphorylation was reduced when rTNNI3K was knocked down. To determine the contractile function modulated by TNNI3K-mediated phosphorylation of cTnI, cardiomyocyte contraction was studied in adult rat ventricular myocytes. The contraction of cardiomyocytes increased with rTNNI3K overexpression and decreased with rTNNI3K knockdown. We conclude that TNNI3K may be a novel mediator of cTnI phosphorylation and contribute to the regulation of cardiac myofilament contraction function.

Proteomic Investigation of Changes in Rat Skeletal Muscle after Exercise-Induced Fatigue

The mechanisms of exercise-induced fatigue have not been investigated using proteomic techniques, an approach that could improve our understanding and generate novel information regarding the effects of exercise. In this study, the proteom alterations of rat skeletal muscle were investigated during exercise-induced fatigue. The proteins were extracted from the skeletal muscle of SD rat thigh, and then analyzed by two-dimensional electrophoresis and PDQuest software. Compared to control samples, 10 significantly altered proteins were found in exercise samples, two of them were upregulated and eight of them were downregulated. These proteins were identified by MALDI TOF-MS. The two upregulated proteins were identified as MLC1 and myosin L2 (DTNB) regulatory light-chain precursors. The eight decreased proteins are Glyceraldehyde-3-phosphate Dehydrogenas (GAPDH); Beta enolase; Creatine kinase M chain (M-CK); ATP-AMP Transphosphorylase (AK1); myosin heavy chain (MHC); actin; Troponin I, fast-skeletal muscle (Troponin I fast-twitch isoform), fsTnI; Troponin T, fast-skeletal muscle isoforms (TnTF). In these proteins, four of the eight decreased proteins are related directly or indirectly to exercise induced fatigue. The other proteins represent diverse sets of proteins including enzymyes related to energy metabolism, skeletal muscle fabric protein and protein with unknown functions. They did not exhibit evident relationship with exercise-induced fatigue. Whereas the two identified increased proteins exhibit evident relationship with fatigue. These findings will help in understanding the mechanisms involved in exercise-induced fatigue.

The analysis of pericardial fluid in forensic practice / 法医学杂志

Pericardial fluid is a kind of serous fluid in pericardial cavity. Because blood undergoes postmortem changes such as autolysis and putrefaction, vitreous humor is limited,cerebrospinal fluid is easily mixed with blood, pericardial fluid, on the other hand, exists in a closed cavity and can be hardly contaminated by postmortem changes, and also is easily obtained. Pericardial fluid not only plays an important role in clinic practice, but also is widely applicable in forensic practice. This paper briefly presented the properties of pericardial fluid and its clinical significance. It reviewed biochemical changes in decedents died of heart diseases, drowning and asphyxia, and explored the significance in medico-legal investigation. Moreover, application of pericardial fluid in forensic serology, forensic toxicological analysis and other fields were also discussed. Pericardial fluid analysis may provide important information for determination of the cause of death with further investigation concerning forensic applicability of pericardial fluid.

Study of CTnI immunohistochemistry on acute myocardial infarction in rabbits / 法医学杂志

OBJECTIVE@#To investigate the signification of CTnI in acute myocardial infarction.@*METHODS@#The model of myocardial infarction was established by ligating the left ventricle branch. Immunohistochemistry and image analysis were used to detect the change of CTnI in the model, and The sensitivity of immunohistochemistry and HE coloration were also compared.@*RESULTS@#The acute myocardial infarction tissue showed obvious depletion of CTnI, there was no characterization of myocardial infarction in HE coloration.@*CONCLUSION@#CTnI is sensitive to diagnosis of acute myocardial infarction.

Influência do pré-condicionamento isquêmico na proteçäo miocárdica em revascularizaçäo do miocárdio com pinçamento intermitente da aorta / Influence of the ischemic preconditioning in the myocardial protection in myocardial revascularization with intermittent aortic cross-clamping

Objetivo: Este estudo testa a hipótese de que curtos períodos de isquemia podem aumentar a proteçäo obtida pelo pinçamento intermitente da aorta. Métodos: No grupo controle (18), a operaçäo foi realizada com hipotermia sistêmica a 32 ºC com pinçamento intermitente da aorta e uso de circulaçäo extracorpórea (CEC). No segundo grupo, denominado de pré-condicionamento (17), foram acrescidos dois pinçamentos de 3 minutos da aorta com intervalo de 2 minutos de reperfusäo entre eles, previamente ao pinçamento intermitente da forma convencional. CK-MB, troponina I, adenosina e lactato foram obtidos do seio ocoronário no início da circulaçäo extracorpórea (1), ao final da segunda anastomose (2) e ao final da CEC (3). Resultados: Os níveis de CK-MB e troponina I apresentaram uma leve tendência a aumentar ao final da CEC no grupo controle, enquanto os de adenosina e lactato näo apresentaram diferença. (Ver tabela). Conclusäo: Concluímos que o pré-condicionamento isquêmico näo promoveu melhora significante na proteçäo miocárdica