MICU3 Regulates Mitochondrial Calcium and Cardiac Hypertrophy.

BACKGROUND: Calcium (Ca2+) uptake by mitochondria occurs via the mitochondrial Ca2+ uniporter. Mitochondrial Ca2+ uniporter exists as a complex, regulated by 3 MICU (mitochondrial Ca2+ uptake) proteins localized in the intermembrane space: MICU1, MICU2, and MICU3. Although MICU3 is present in the heart, its role is largely unknown. METHODS: We used CRISPR-Cas9 to generate a mouse with global deletion of MICU3 and an adeno-associated virus (AAV9) to overexpress MICU3 in wild-type mice. We examined the role of MICU3 in regulating mitochondrial calcium ([Ca2+]m) in ex vivo hearts using an optical method following adrenergic stimulation in perfused hearts loaded with a Ca2+-sensitive fluorophore. Additionally, we studied how deletion and overexpression of MICU3, respectively, impact cardiac function in vivo by echocardiography and the molecular composition of the mitochondrial Ca2+ uniporter complex via Western blot, immunoprecipitation, and Blue native-PAGE analysis. Finally, we measured MICU3 expression in failing human hearts. RESULTS: MICU3 knock out hearts and cardiomyocytes exhibited a significantly smaller increase in [Ca2+]m than wild-type hearts following acute isoproterenol infusion. In contrast, heart with overexpression of MICU3 exhibited an enhanced increase in [Ca2+]m compared with control hearts. Echocardiography analysis showed no significant difference in cardiac function in knock out MICU3 mice relative to wild-type mice at baseline. However, mice with overexpression of MICU3 exhibited significantly reduced ejection fraction and fractional shortening compared with control mice. We observed a significant increase in the ratio of heart weight to tibia length in hearts with overexpression of MICU3 compared with controls, consistent with hypertrophy. We also found a significant decrease in MICU3 protein and expression in failing human hearts. CONCLUSIONS: Our results indicate that increased and decreased expression of MICU3 enhances and reduces, respectively, the uptake of [Ca2+]m in the heart. We conclude that MICU3 plays an important role in regulating [Ca2+]m physiologically, and overexpression of MICU3 is sufficient to induce cardiac hypertrophy, making MICU3 a possible therapeutic target.

Litiasis masiva de la vía biliar intra y extra hepática. Reporte de 2 casos / Massive intra- and extra-hepatic bile duct lithiasis. Report of 2 cases

Resumen La presencia conjunta y masiva de cálculos biliares de la vía biliar, tanto intra como extra hepática, es una rara entidad dentro de la población occidental. A continuación, se presentan 2 casos, los cuales debutan con cuadro clínico de dolor en hipocondrio derecho y con datos clínicos y de laboratorio de obstrucción de la vía biliar, y que mediante estudio de colangio resonancia, se evidencian múltiples litos endoluminales de la vía biliar de manera global, además se muestra del tratamiento de uno de los casos mediante CPRE con evacuación exitosa de los cálculos biliares.

Abstract The joint and massive presence of gallstones from the bile duct, both intra and extra hepatic, is a rare entity within the western population. Two cases are presented below, which debuted with a clinical picture of pain in the right hypo chondrium and with a clinical picture of pain in the right hypochondrium and with clinical and laboratory data of bile duct obstruction, and that by means of a resonance cholangiography study, multiple endoluminal stones of the bile duct are evidenced. Overall, it also shows the treatment of one of the cases by ERCP with successful evacuation of the gallstones.

Distinct effects of cardiac mitochondrial calcium uniporter inactivation via EMRE deletion in the short and long term.

Transport of Ca2+ into mitochondria is thought to stimulate the production of ATP, a critical process in the heart's fight or flight response, but excess Ca2+ can trigger cell death. The mitochondrial Ca2+ uniporter complex is the primary route of Ca2+ transport into mitochondria, in which the channel-forming protein MCU and the regulatory protein EMRE are essential for activity. In previous studies, chronic Mcu or Emre deletion differed from acute cardiac Mcu deletion in response to adrenergic stimulation and ischemia/reperfusion (I/R) injury, despite equivalent inactivation of rapid mitochondrial Ca2+ uptake. To explore this discrepancy between chronic and acute loss of uniporter activity, we compared short-term and long-term Emre deletion using a novel conditional cardiac-specific, tamoxifen-inducible mouse model. After short-term Emre deletion (3 weeks post-tamoxifen) in adult mice, cardiac mitochondria were unable to take up Ca2+, had lower basal mitochondrial Ca2+ levels, and displayed attenuated Ca2+-induced ATP production and mPTP opening. Moreover, short-term EMRE loss blunted cardiac response to adrenergic stimulation and improved maintenance of cardiac function in an ex vivo I/R model. We then tested whether the long-term absence of EMRE (3 months post-tamoxifen) in adulthood would lead to distinct outcomes. After long-term Emre deletion, mitochondrial Ca2+ handling and function, as well as cardiac response to adrenergic stimulation, were similarly impaired as in short-term deletion. Interestingly, however, protection from I/R injury was lost in the long-term. These data suggest that several months without uniporter function are insufficient to restore bioenergetic response but are sufficient to restore susceptibility to I/R.

Resveratrol Prevents Right Ventricle Dysfunction, Calcium Mishandling, and Energetic Failure via SIRT3 Stimulation in Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) is characterized by pulmonary vessel remodeling; however, its severity and impact on survival depend on right ventricular (RV) failure. Resveratrol (RES), a polyphenol found in red wine, exhibits cardioprotective effects on RV dysfunction in PAH. However, most literature has focused on RES protective effect on lung vasculature; recent finding indicates that RES has a cardioprotective effect independent of pulmonary arterial pressure on RV dysfunction, although the underlying mechanism in RV has not been determined. Therefore, this study is aimed at evaluating sirtuin-3 (SIRT3) modulation by RES in RV using a monocrotaline- (MC-) induced PAH rat model. Myocyte function was evaluated by confocal microscopy as cell contractility, calcium signaling, and mitochondrial membrane potential (ΔΨm); cell energetics was assessed by high-resolution respirometry, and western blot and immunoprecipitation evaluated posttranslational modifications. PAH significantly affects mitochondrial function in RV; PAH is prone to mitochondrial permeability transition pore (mPTP) opening, thus decreasing the mitochondrial membrane potential. The compromised cellular energetics affects cardiomyocyte function by decreasing sarco-endoplasmic reticulum Ca2+-ATPase (SERCA) activity and delaying myofilament unbinding, disrupting cell relaxation. RES partially protects mitochondrial integrity by deacetylating cyclophilin-D, a critical component of the mPTP, increasing SIRT3 expression and activity and preventing mPTP opening. The preserved energetic capability rescues cell relaxation by maintaining SERCA activity. Avoiding Ca2+ transient and cell contractility mismatch by preserving mitochondrial function describes, for the first time, impairment in excitation-contraction-energetics coupling in RV failure. These results highlight the importance of mitochondrial energetics and mPTP in PAH.

Amorphous SiO2 nanoparticles promote cardiac dysfunction via the opening of the mitochondrial permeability transition pore in rat heart and human cardiomyocytes.

BACKGROUND: Silica nanoparticles (nanoSiO2) are promising systems that can deliver biologically active compounds to tissues such as the heart in a controllable manner. However, cardiac toxicity induced by nanoSiO2 has been recently related to abnormal calcium handling and energetic failure in cardiomyocytes. Moreover, the precise mechanisms underlying this energetic debacle remain unclear. In order to elucidate these mechanisms, this article explores the ex vivo heart function and mitochondria after exposure to nanoSiO2. RESULTS: The cumulative administration of nanoSiO2 reduced the mechanical performance index of the rat heart with a half-maximal inhibitory concentration (IC50) of 93 µg/mL, affecting the relaxation rate. In isolated mitochondria nanoSiO2 was found to be internalized, inhibiting oxidative phosphorylation and significantly reducing the mitochondrial membrane potential (ΔΨm). The mitochondrial permeability transition pore (mPTP) was also induced with an increasing dose of nanoSiO2 and partially recovered with, a potent blocker of the mPTP, Cyclosporine A (CsA). The activity of aconitase and thiol oxidation, in the adenine nucleotide translocase, were found to be reduced due to nanoSiO2 exposure, suggesting that nanoSiO2 induces the mPTP via thiol modification and ROS generation. In cardiac cells exposed to nanoSiO2, enhanced viability and reduction of H2O2 were observed after application of a specific mitochondrial antioxidant, MitoTEMPO. Concomitantly, CsA treatment in adult rat cardiac cells reduced the nanoSiO2-triggered cell death and recovered ATP production (from 32.4 to 65.4%). Additionally, we performed evaluation of the mitochondrial effect of nanoSiO2 in human cardiomyocytes. We observed a 40% inhibition of maximal oxygen consumption rate in mitochondria at 500 µg/mL. Under this condition we identified a remarkable diminution in the spare respiratory capacity. This data indicates that a reduction in the amount of extra ATP that can be produced by mitochondria during a sudden increase in energy demand. In human cardiomyocytes, increased LDH release and necrosis were found at increased doses of nanoSiO2, reaching 85 and 48%, respectively. Such deleterious effects were partially prevented by the application of CsA. Therefore, exposure to nanoSiO2 affects cardiac function via mitochondrial dysfunction through the opening of the mPTP. CONCLUSION: The aforementioned effects can be partially avoided reducing ROS or retarding the opening of the mPTP. These novel strategies which resulted in cardioprotection could be considered as potential therapies to decrease the side effects of nanoSiO2 exposure.

Infarto bitalámico en el área de la arteria de Percheron / Bithalamic infarction in Percheron artery area

Resumen Caso de una paciente de 43 años, que acude al servicio de urgencias con alteraciones en el estado de conciencia, en el lenguaje y visuales. La valoró el servicio de neurología, se solicitó un estudio de resonancia magnética en el que se reportaron lesiones bitalámicas en el territorio de la arteria de Percheron, por lo que se estableció el diagnóstico de infarto bitalámico. Reconocer esta afectación por resonancia magnética es fundamental para el diagnóstico preciso de esta entidad.

Abstract The case of a 43-year-old female patient is presented. She arrived to the emergency room of our hospital, with alterations in consciousness, language and vision. She was evaluated by the neurology department and requested a magnetic resonance, finding bithalamic lessions in the Percheron's artery area. This concluded in the diagnosis of a bithalamic infarct. Recognizing that a magnetic resonance is fundamental for the accurate diagnosis of this nosological entity.

Ex Vivo Cardiotoxicity of Antineoplastic Casiopeinas Is Mediated through Energetic Dysfunction and Triggered Mitochondrial-Dependent Apoptosis.

Casiopeinas are a group of copper-based antineoplastic molecules designed as a less toxic and more therapeutic alternative to cisplatin or Doxorubicin; however, there is scarce evidence about their toxic effects on the whole heart and cardiomyocytes. Given this, rat hearts were perfused with Casiopeinas or Doxorubicin and the effects on mechanical performance, energetics, and mitochondrial function were measured. As well, the effects of Casiopeinas-triggered cell death were explored in isolated cardiomyocytes. Casiopeinas III-Ea, II-gly, and III-ia induced a progressive and sustained inhibition of heart contractile function that was dose- and time-dependent with an IC50 of 1.3 ± 0.2, 5.5 ± 0.5, and 10 ± 0.7 µM, correspondingly. Myocardial oxygen consumption was not modified at their respective IC50, although ATP levels were significantly reduced, indicating energy impairment. Isolated mitochondria from Casiopeinas-treated hearts showed a significant loss of membrane potential and reduction of mitochondrial Ca2+ retention capacity. Interestingly, Cyclosporine A inhibited Casiopeinas-induced mitochondrial Ca2+ release, which suggests the involvement of the mitochondrial permeability transition pore opening. In addition, Casiopeinas reduced the viability of cardiomyocytes and stimulated the activation of caspases 3, 7, and 9, demonstrating a cell death mitochondrial-dependent mechanism. Finally, the early perfusion of Cyclosporine A in isolated hearts decreased Casiopeinas-induced dysfunction with reduction of their toxic effect. Our results suggest that heart cardiotoxicity of Casiopeinas is similar to that of Doxorubicin, involving heart mitochondrial dysfunction, loss of membrane potential, changes in energetic metabolites, and apoptosis triggered by mitochondrial permeability.

Challenges and opportunities in establishing a collaborative multisite observational study of chronic diseases and lifestyle factors among adults in Puerto Rico.

BACKGROUND: Prevalence of chronic diseases and unhealthy lifestyle behaviors among the adult population of Puerto Rico (PR) is high; however, few epidemiological studies have been conducted to address these. We aimed to document the methods and operation of establishing a multisite cross-sectional study of chronic diseases and risk factors in PR, in partnership with academic, community, clinical, and research institutions. METHODS: The Puerto Rico Assessment of Diet, Lifestyle and Diseases (PRADLAD) documented lifestyle and health characteristics of adults living in PR, with the goal of informing future epidemiological and intervention projects, as well as public health, policy, and clinical efforts to help improve the population's health. The study was conducted in three primary care clinics in the San Juan, PR metropolitan area. Eligible volunteers were 30-75y, living in PR for at least 10 months of the previous year, and able to answer interviewer-administered questionnaires without assistance. Questions were recorded electronically by trained interviewers, and included socio-demographic characteristics, lifestyle behaviors, self-reported medically-diagnosed diseases, and psychosocial factors. Waist and hip circumferences were measured following standardized protocols. A subset of participants answered a validated food frequency questionnaire, a legumes questionnaire, and had medical record data abstracted. Process and outcome evaluation indicators were assessed. RESULTS: The study screened 403 participants in 5 months. Of these, 396 (98%) were eligible and 380 (94%) had reliable and complete information. A subset of 242 participants had valid dietary data, and 236 had medical record data. The mean time to complete an interview was 1.5 h. Participants were generally cooperative and research collaborators were fully engaged. Having multiple sites helped enhance recruitment and sociodemographic representation. Diagnosed conditions were prevalent across sites. Challenges in data monitoring, interviewer training, and scheduling were identified and corrected, and should be addressed in future studies. CONCLUSIONS: Epidemiological studies in PR can be successfully implemented in partnership with multiple institutions. Effective recruitment and implementation requires concerted planning and continued involvement from partners, frequent quality control, brief interviews, reasonable incentives, and thorough training/re-training of culturally-sensitive interviewers. Further studies are feasible and needed to help address highly prevalent chronic conditions in PR.

Views on HPV and HPV Vaccination: The Experience at a Federal Qualified Clinic in Puerto Rico.

OBJECTIVE: The purpose of this study was to understand through a quantitative assessment, the views of HPV and HPV vaccination among parents of sons from a FQHC in PR. METHODS: A self-administered questionnaire was given to a convenience sample of 200 parents of sons 9-17 years old. RESULTS: Nearly 30% of the parents reported that their sons had initiated the HPV vaccine regimen. Health care provider recommendation was significantly associated with vaccine initiation. Among parents of unvaccinated sons, the main reason for not getting the HPV vaccine was they did not know that boys were allowed to get the vaccine. CONCLUSIONS: Future efforts should focus on multilevel interventions aimed to increase knowledge as well as other modified behavioral determinants in parents of young males about HPV and the vaccine. Capacity building efforts should be targeted also to increase health providers' education and communication skills to promote HPV vaccination effectively.

Therapeutic silencing of HPV 16 E7 by systemic administration of siRNA-neutral DOPC nanoliposome in a murine cervical cancer model with obesity.

PURPOSE: To evaluate the effectiveness of a neutral DOPC nanoliposome system for the delivery of siRNA to tumor cells in an obese murine cervical cancer model. METHODS: In vitro silencing of E6-E7 mRNA and E7 protein using siRNAE6 or siRNAE7 was analyzed in TC-1 cells by RT-PCR and Western blot. Silencing and antitumor capacities of siRNAE7-DOPC-nanoparticles (NP) were tested in vivo in both normal and obese mice using qPCR. These NPs were administered twice a week for 15 days and tumor volume and weight were recorded. RESULTS: Levels of in vitro E6-E7 silencing were 90% for mRNA and 60% for protein when siRNAE7 was used. On the other hand when siRNAE6 was used, the levels of silencing were 50% for E6-E7 mRNA and only 20% for protein. In vivo E7 mRNA silencing by siRNAE7-DOPC-NP was similar (60%) in both non-obese and obese mouse models. The therapeutic study showed a 65% decrease in tumor volume and a 57% reduction in tumor weight as compared to the control groups. CONCLUSION: There was no negative impact of obesity on the antitumor activity of siRNA-DOPC-NP in obese mice.

HPV Awareness and Vaccine Willingness Among Dominican Immigrant Parents Attending a Federal Qualified Health Clinic in Puerto Rico.

The purpose of this study was to describe the socio-demographic characteristics, awareness of human papillomavirus (HPV), and willingness to vaccinate among a convenience sample of 60 immigrant Dominican parents of adolescent sons in a Federal Qualified Health Clinic in Puerto Rico. Participation involved completing a self-administered survey. Even though more than half of the parents had not received proper HPV vaccine orientation from healthcare provider (58.3 %) nor asked provider for vaccination recommendation for their adolescent sons (56.7 %), most parents were aware of HPV (91.7 %) and HPV vaccination among males (55.0 %). Among those with unvaccinated sons, willingness to vaccinate the son within the next year was high (83.8 %). The low vaccination percentage (31.7 %) and information exchange between the parents and the son's healthcare provider indicates an opportunity for future culturally tailored interventions to target HPV vaccination among healthcare providers and parents of foreign descent in order to increase HPV vaccine uptake among males.

Factores de riego de deserción presentes en almnos repitentes de las carreras de enfermería y kinesiología en una universidad Chilena / Dropout risk factors identified in students repeating courses in nursing and kinesiology programs at a Chilean university

Las altas tasas de repitencia y deserción en alumnos universitarios ha sido tema de preocupación de docentes y autoridades. Objetivo: Describir cómo se presentan los factores de riesgo de deserción en alumnos repitentes de primer año de las carreras de Enfermería y Kinesiología de una universidad chilena. Material y método: Estudio cuantitativo descriptivo en el cual se aplicó un instrumento validado a 83 alumnos que se encontraban matriculados en las carreras señaladas, teniendo como criterio de inclusión que hayan reprobado al menos una asignatura. Se realizó análisis estadístico (SPSS) de la información recopilada. Resultados: se observa que la mayoría de los estudiantes usa como técnica de estudio la lectura de los contenidos seguido de aquellos que subrayan la materia; existe un porcentaje importante de estudiantes que señalan haber cursado una carrera universitaria previa; el mayor número de estudiantes financia sus estudios a través de créditos y becas; el porcentaje más alto pertenece a un grupo con un ingreso económico familiar de hasta $350.000 pesos; un gran número de estudiantes cursó su enseñanza media en un establecimiento municipalizado; la gran mayoría de los padres de los estudiantes alcanzó un nivel educacional secundario y secundario incompleto; y finalmente un gran número de estudiantes señala que son los primeros del grupo familiar en ingresar a cursar estudios superiores. Conclusiones: Es posible inferir que en este grupo de estudiantes se encuentra presente algunos de los factores de riesgo de deserción estudiados, lo que los puede llevar a desertar en algún momento de su carrera.

High repetition and dropout rates for college students have raised concern among teaching personnel and authorities. This paper presents research conducted among first-year Nursing and Kinesiology students at a Chilean university, with the aim of describing how attrition risk factors affect this group of students repeating grades. It is a quantitative descriptive study in which a validated questionnaire was applied to 83 students who were enrolled in these programs, with the selection criterion of having failed at least one course. A statistical analysis (SPSS) was then applied to the information collected. Results: it was found that the majority of the students surveyed adopt a study technique consisting of reading and then underlining the course materials; a significant percentage indicated that they had previously been enrolled in a different university course; more students finance their studies using credits or scholarships than through any other funding mechanism; the most heavily represented family income group is the group with incomes of up to CLP350,000; a large number of those surveyed received secondary education at a municipally funded school; the vast majority of students’ parents had at least started secondary education but never entered the tertiary level; and finally, a large number of students indicated that they are the first in their immediate family to enter any form of higher education. Conclusions: It can be concluded that this group of students presents a number of the dropout risk factors already studied, which could lead them to abandon higher education at any point.