Os Efeitos da Doxorrubicina na Biossíntese e no Metabolismo do Heme em Cardiomiócitos / Effects of Doxorubicin on Heme Biosynthesis and Metabolism in Cardiomyocyte

Resumo Fundamento A doxorrubicina está associada à cardiotoxicidade e à morbidade cardíaca tardia. O heme está relacionado ao stress oxidativo celular. Entretanto, sua regulação específica em cardiomiócitos sob os efeitos de doxorrubicina ainda não foi documentada. Objetivo Nosso objetivo é avaliar as alterações de enzimas limitantes de velocidade no caminho metabólico do heme sob o efeito de doxorrubicina. Métodos Cardiomiócitos H9c2 com doxorrubicina em concentrações diferentes (1, 2, 5, 10μM respectivamente). Os testes de PCR em tempo real e Western Blot foram usados para determinar a expressão de proteína e mRNA para quatro enzimas cruciais (ALAS1, ALAS2, HOX-1, e HOX-2) que regulam o metabolismo do heme celular, e os níveis de heme foram detectados por ELISA. Um p<0,01 foi considerado significativo. Resultados Observamos um padrão com alteração dependendo da dose nos níveis de heme nas células H9c2 com o nível mais alto na concentração de 5μM de doxorrubicina, o que ocorreu sincronicamente com o nível mais alto de regulação para cima de ALAS1, bem como as enzimas degenerativas HOX-1 e HOX-2 na expressão de proteína e mRNA. Em contraste, observamos que a ALAS2 foi regulada para baixo gradualmente, inversamente proporcional às concentrações de doxorrubicina. Conclusão O aumento da expressão de ALAS1 pode ter um papel na elevação do nível do heme quando o cardiomiócito H9c2 for exposto à doxorrubicina, e pode ser um alvo terapêutico para a toxicidade miocárdica induzida por doxorrubicina. (Arq Bras Cardiol. 2021; 116(2):315-322)

Abstract Background Doxorubicin is associated with cardiotoxicity and late cardiac morbidity. Heme is related to cellular oxidative stress. However, its specific regulation in cardiomyocytes under doxorubicin effects has not yet been documented. Objective This study seeks to evaluate the changing profiles of rate-limiting enzymes in the heme metabolism pathway under the effect of doxorubicin. Methods H9c2 cardiomyocytes were incubated with doxorubicin at different concentrations (1,2,5,10μM respectively). The real-time PCR and Western Blot were used to determine the mRNA and protein expression for four pivotal enzymes (ALAS1, ALAS2, HOX-1, and HOX-2) regulating cellular heme metabolism, as well as the levels of heme were detected by ELISA. p<0.01 was considered significant. Results This study observed a dose-dependent changing pattern in heme levels in H9c2 cells with the highest level at the 5μM concentration for doxorubicin, which occurred synchronously with the highest upregulation level of ALAS1, as well as the degradative enzymes, HOX-1, and HOX-2 in mRNA and protein expression. By contrast, ALAS2, contrary to the increasing concentrations of doxorubicin, was found to be progressively down-regulated. Conclusion The increase in ALAS1 expression may play a potential role in the heme level elevation when H9c2 cardiomyocyte was exposed to doxorubicin and may be a potential therapeutic target for doxorubicin-induced myocardial toxicity. (Arq Bras Cardiol. 2021; 116(2):315-322)

Synergistic antitumor activity of artesunate and HDAC inhibitors through elevating heme synthesis synergistic upregulation of ALAS1 expression

Artemisinin and its derivatives (ARTs) were reported to display heme-dependent antitumor activity. On the other hand, histone deacetylase inhibitors (HDACi) were known to be able to promote heme synthesis in erythroid cells. Nevertheless, the effect of HDACi on heme homeostasis in non-erythrocytes remains unknown. We envisioned that the combination of HDACi and artesunate (ARS) might have synergistic antitumor activity through modulating heme synthesis. studies revealed that combination of ARS and HDACi exerted synergistic tumor inhibition by inducing cell death. Moreover, this combination exhibited more effective antitumor activity than either ARS or HDACi monotherapy in xenograft models without apparent toxicity. Importantly, mechanistic studies revealed that HDACi coordinated with ARS to increase 5-aminolevulinate synthase (ALAS1) expression, and subsequent heme production, leading to enhanced cytotoxicity of ARS. Notably, knocking down significantly blunted the synergistic effect of ARS and HDACi on tumor inhibition, indicating a critical role of ALAS1 upregulation in mediating ARS cytotoxicity. Collectively, our study revealed the mechanism of synergistic antitumor action of ARS and HDACi. This finding indicates that modulation of heme synthesis pathway by the combination based on ARTs and other heme synthesis modulators represents a promising therapeutic approach to solid tumors.

The role of ClpX in erythropoietic protoporphyria

ABSTRACT Hemoglobin is an essential biological component of human physiology and its production in red blood cells relies upon proper biosynthesis of heme and globin protein. Disruption in the synthesis of these precursors accounts for a number of human blood disorders found in patients. Mutations in genes encoding heme biosynthesis enzymes are associated with a broad class of metabolic disorders called porphyrias. In particular, one subtype - erythropoietic protoporphyria - is caused by the accumulation of protoporphyrin IX. Erythropoietic protoporphyria patients suffer from photosensitivity and a higher risk of liver failure, which is the principle cause of morbidity and mortality. Approximately 90% of these patients carry loss-of-function mutations in the enzyme ferrochelatase (FECH), while 5% of cases are associated with activating mutations in the C-terminus of ALAS2. Recent work has begun to uncover novel mechanisms of heme regulation that may account for the remaining 5% of cases with previously unknown genetic basis. One erythropoietic protoporphyria family has been identified with inherited mutations in the AAA+ protease ClpXP that regulates ALAS activity. In this review article, recent findings on the role of ClpXP as both an activating unfoldase and degrading protease and its impact on heme synthesis will be discussed. This review will also highlight the role of ClpX dysfunction in erythropoietic protoporphyria.

Prevalence of honey bee (Apis mellifera) viruses in temperate and subtropical regions from Argentina / Prevalencia de virus en abejas melíferas (Apis mellifera) en ambientes templados y subtropicales de Argentina

In Argentina, bee virus studies are still incipient, and there are no studies regarding the climatic effect. The aim of this study was to assess and compare the presence of honeybee viruses in different climatic regions from Argentina. A total of 385 colonies distributed in five Argentinean eco-regions were examined to evaluate the percentage of infestation with Varroa destructor and the presence of seven virus species (Deformed wing virus, DWV; Acute bee paralysis virus, ABPV; Chronic bee paralysis virus, CBPV; Black queen cell virus, BQCV; Kashmer bee virus, KBV; Israeli acute bee paralysis virus, IAPV; and Sacbrood bee virus, SBV) after honey yield. Two viruses, KBV and IAPV, were not detected. The other five viruses were found in different prevalences: DWV (35%), ABPV (21.5%), BQCV (8.0%), CBPV (2.2%), and SBV (1.1%). We found double and triple viral associations in approximately 25% of the sampled colonies. The mean V. destructor infestation in the colonies prior to the acaricide treatment was 7.12% ± 8.7%. The knowledge of the prevalence of these viruses in the region and their relation with the mite and other possible influencing factors is important for preventing colony losses. Further studies are necessary to identify the risk factors associated with virus presence and its relationship with other pathogens such as V. destructor.

En Argentina, los estudios sobre prevalencia de virus en abejas continúan siendo incipientes y no existen reportes acerca de cómo inciden sobre dicha prevalencia las variables climáticas. El objetivo de este estudio fue evaluar y comparar la presencia de virus en abejas melíferas en diferentes regiones agroecológicas de Argentina. A tal fin se evaluaron 385 colmenas distribuidas en 5 regiones agroecológicas de las provincias de Chaco y Santa Fe; en ellas se analizó el porcentaje de infestación con Varroa destructor (ácaro patógeno de abejas) y la presencia de 7 especies de virus (DWV, virus de las alas deformadas; ABPV, virus de la parálisis aguda de la abeja; CBPV, virus de la parálisis crónica de la abeja; BQCV, virus de celda negra de la reina; KBV, virus de la abeja de Cachemira; IAPV, virus israelí de la parálisis aguda y SBV, virus de la cría ensacada). luego de la cosecha de miel. Dos virus (KBV y IAPV) no fueron detectados. Las otras 5 especies de virus se encontraron con prevalencias variables: DWV (35%), ABPV (21,5%), BQCV (8%), CBPV (2,2%) y SBV (1,1%). Fue posible identificar la presencia de 3 y hasta 3 virus simultáneamente en el 25% de las colmenas evaluadas. El promedio de infestación por V. destructor en las colmenas luego de la cosecha de miel y antes del tratamiento con acaricidas fue de 7,12% (±8,7). Conocer la prevalencia de virus en las diferentes regiones agroecológicas y su relación con la presencia del ácaro V. destructor e identificar otros posibles factores que podrían influir en su presencia es relevante para definir estrategias que reduzcan la mortandad de colmenas. Es necesario realizar estudios adicionales para identificar los factores de riesgo asociados a la presencia de virus en las colmenas y su relación con otros patógenos, como V. destructor.

Fluctuating asymmetry in Apis mellifera(Hymenoptera: Apidae) as bioindicator of anthropogenic environments / Asimetría fluctuante en Apis mellifera (Hymenop-tera: Apidae) como bioindicador de ambientes antropo-génicos

The successful distribution of A. melliferais due to their ability to adjust to seasonal variations, considerable control over their internal physical environment and exploration of different resources. However, their populations have experienced different forms and levels of environmental pressure. This research aimed to verify the phenotypic plasticity in both size and shape of wings in A. melliferausing fluctuating asymmetry, based on geometric morphometrics from apiaries located in sites with high and low levels of anthropization. We sampled 16 locations throughout all five geographic regions of Brazil. At each site, samples were collected from 20 beehives installed in apiaries: 10 installed near high anthropogenic environments (Cassilàndia - MS, Fortaleza - CE, Maringá - PR, Aquidauana - MS, Rolim de Moura - RO, Riachuelo - SE, Ubirata - PR and Piracicaba - SP), and 10 in sites with low levels of human disturbance (Cassilàndia - MS, Itapiúna CE, Uniao da Vitoria - PR, Aquidauana - MS, Rolim de Moura - RO, Pacatuba - SE, Erval Seco - RS, Rio Claro - SP). A sample of 10 individuals was taken in each hive, totaling 200 per location, for a total of 1 600 individuals. We used fluctuating asymmetry (FA) in size and shape of the forewing through geometric morphometrics. The FA analysis was conducted in order to check bilateral differences. The indexes of size and shape were submitted to analysis of variance (ANOVA), where the characters evaluated were used as factors to verify the size and shape differences. The results indicated an asymmetry on the shape of the wing (P < 0.001) but no asymmetry was observed on wing size. Considering FA as an environmental response and high and low impacted areas as a fixed factor, we observed significant differences (P < 0.05). The results for the wing shape in A. melliferademonstrated that this feature undergoes more variation during ontogeny compared to the variation in size. We concluded that bee samples collected from colonies with higher levels of human disturbance had higher wing-shape asymmetry; the variation of fluctuating asymmetry in the wing shape of honeybees can be used as an indicator of the degree of environmental anthropization.

La distribución exitosa de A. melliferase debe a su capacidad para adaptarse a las variaciones estacionales, controlar considerablemente su ambiente físico interno y por la exploración de recursos. Sin embargo, sus poblaciones experimentan diferentes formas y niveles de presión ambiental. Esta investigación evaluó colmenares, ubicadas en entornos con distintos niveles de antropización. Ambientes considerados altamente antropogénicos fueron escogidos: áreas urbanas, agrícolas con aplicaciones de insecticidas, y las industrias con grandes áreas (regiones con altos índices de contaminación). Por otra parte, los entornos considerados con bajos niveles de perturbación humana fueron elegidos: áreas de preservación permanente de los bosques restantes (Mata Atlántica, Planalto, Cerrado), áreas ribereñas o reservas ecológicas. Se muestrearon 16 localidades que abarcan las cinco regiones del Brasil. Estamos utilizando la asimetría fluctuante desde el tamaño y la forma del ala anterior por técnicas de morfometría geométrica. En cada sitio, las muestras se obtuvieron de las 20 colmenas instaladas en los colmenares: 10 instalados cerca de entornos altamente antropogénicos (Cassilándia - MS, Fortaleza - CE, Maringá - PR, Aquidauana - MS, Rolim de Moura - RO, Riachuelo - SE, Ubirata - PR y Piracicaba - SP) y 10 en sitios de bajo nivel de perturbación humana (Cassilándia - MS, ItapiúnaCE, Uniao da Vitória - PR, Aquidauana - MS, Rolim de Moura - RO, Pacatuba- SE, Erval Seco - RS, Rio Claro - SP). Los índices de tamaño y forma fueron sometidos a análisis de varianza (ANOVA), donde se utilizaron los caracteres evaluados como factores, para verificar las diferencias de tamaño y forma. La asimetría de análisis fluctuante (AF) se llevó a cabo con el fin de comprobar las diferencias bilaterales. Los resultados indican la existencia de la asimetría de la forma del ala (P < 0.001), pero no se observó asimetría del tamaño del ala. Considerando AF como respuesta ambiental y áreas de alto y bajo grado de alteración humana como factor fijo, observamos diferencias significativas (P < 0.05). Los resultados, para la forma de ala de la A. mellifera,muestran que esta característica se somete a más variación durante la ontogenia en comparación con la variación en el tamaño. Llegamos a la conclusión de que las colonias de abejas recogidas en ambientes con niveles más altos de la perturbación humana tienen una mayor asimetría en forma de ala, por lo que la asimetría fluctuante en forma de alas de las abejas puede ser utilizada como un indicador del grado de antropización del medio ambiente.

Desarrollo de las consultas oculoplastia y cirujía implanto-refractiva del Sistema alas BQO / Development of the consultations oculoplasty and implanto-refractive surgery of System alas BQO

En la actualidad, la gestión de la información en las consultas oftalmológicas de Oculoplastia y Cirugía Implanto-Refractiva se realiza de forma manual. Esto ha provocado duplicidad de datos, acumulación de la información y deterioro de registros médicos, incidiendo como una vulnerabilidad a la hora de procesar la información. La presente investigación tiene como meta, la informatización de los procesos correspondientes a estas consultas, guiada durante todo el ciclo de vida por el Proceso Unificado de Desarrollo (RUP), con el propósito de garantizar un medio para el almacenamiento seguro de la información y de su procesamiento. Se utiliza Visual Paradigm como herramienta de modelado. Para la implementación de las funcionalidades se emplea la plataforma .NET mediante el lenguaje de programación C#, auxiliado por el Framework 2.0 y Postgres SQL como gestor de bases de datos. Como resultado de su implementación se espera proporcionar al usuario una forma viable de gestionar la información en las consultas oftalmológicas, brindado una mayor confiabilidad y seguridad tanto al personal de la institución como a los pacientes que requieren de dichos servicios. Por otra parte, los especialistas contarán con una Historia Clínica Electrónica única, que permitirá el seguimiento de la salud del paciente y la disponibilidad de la información para que puedan ser examinados los diagnósticos emitidos de estos con anterioridad(AU)

Currently, the information management in the ophthalmological queries of Oculoplasty and Refractive Implant Surgery is performed manually. This has resulted in duplication of data, accumulation of information and deterioration of the medical records, becoming an invulnerability when processing of information occurs. The present research is intended to the computerization of the processes of this consultations, guided throughout the life cycle by the Rational Unified Process (RUP), in order to guarantee a means for the safe storage and processing of the information. The Visual Paradigm is employed as a modeling tool. For the implementation of the functionalities we used the platform .NET, through the programming language C#, helped by the Framework 2.0 and the Postgres SQL as a database manager. As a result from its implementation, it is expected to provide the user with a viable way of managing the information on the eye care consultations, providing also a better reliability and safety to both, the institution staff and the patients requiring that system. Moreover, the specialists will have a single electronic health record that will allow monitoring the patient´s health and the availability of the information so that the latest diagnoses can be examined. better reliability and safety to both, the institution staff and the patients requiring that system. Moreover, the specialists will have a single electronic health record that will allow monitoring the patient´s health and the availability of the information so that the latest diagnoses can be examined(AU)

Colgajo en alas: una alternativa para la reconstrucción de las neosindactilias cicatriciales postquemaduras pediátricas / Use of wing flaps to correct web space sequels of hand burns in children

Background: With finger growth, sequels of burns in children located in the palm of the hand and web spaces tend to form syndactylyes, which can limit the opening of fingers. These sequels need a reconstructive surgical approach. Aim: To describe the use of flap wings for syndactylyes occurring after burns in children and analyze its surgical results. Materials and methods: Retrospective review of 50 medical records of children undergoing surgery using the flap wings technique in the hand, collecting demographic, clinical and surgical variables. Results: In the 50 children analyzed, 69 surgical procedures using the flap wing technique were performed, corresponding to 1.38 procedures per patient. The burn occurred at 2.2 +/- 3.0 years of age. The surgical procedures were carried out 6.7 +/- 4.5 years after the burn episode, at 8.9 ± 4.9 years of age. Wing flaps were located predominantly in second and third web spaces. Average operating time was 72.2 +/- 34 minutes. Only three (6 percent) children had minor complications. Conclusions: The proposed surgical technique is a useful surgical approach for the burned web space of the hand, with a low proportion of complications.

Introducción: Con el crecimiento de los dedos, las secuelas postquemaduras infantiles localizadas a nivel de la palma y comisuras tenderán a formar neosindactilias cicatriciales, lo que puede limitar la apertura de los dedos, necesitando un abordaje quirúrgico reconstructivo. Objetivo: Describir la técnica "colgajo en alas" en las neosindactilias cicatriciales post quemaduras en niños y, analizar los resultados de las cirugías en que se ha utilizado este procedimiento. Materiales y Métodos: Estudio descriptivo retrospectivo, de revisión aleatoria de 50 fichas de niños sometidos a cirugía con colgajo en alas en mano, de un total de 980 cirugías de mano realizadas en COANIQUEM por cualquier técnica, entre los años 2000-2009, recolectando variables demográficas, clínicas y quirúrgicas. Resultados: Se realizan 69/50 = 1,38 cirugías por paciente usando la técnica de colgajo en alas. La quemadura se produjo en promedio a los 2,2 +/- 3,0 años; la cirugía se realizó a los 6,7 +/- 4,5 años de evolución y a los 8,9 +/- 4,9 años de edad. El tiempo de cirugía en promedio duró 72,2 +/- 34,7 minutos; los colgajos en alas se localizaron con mayor frecuencia en segunda y tercera comisura. Sólo el 6 por ciento de los niños presentó complicaciones menores (3/50). Conclusiones: La técnica quirúrgica propuesta, constituye una herramienta útil en el abordaje de las neosindactilias cicatriciales postquemaduras, de gran versatilidad de uso hacia palmar, dorsal o comisuras contiguas y baja proporción de complicaciones.

Identification of a Hemizygous R170H Mutation in the ALAS2 Gene in a Young Male Patient with X-linked Sideroblastic Anemia

X-linked sideroblastic anemia (XLSA) is a rare hereditary disease characterized by microcytic hypochromic anemia, ineffective erythropoiesis and the presence of numerous ringed sideroblasts in the bone marrow. The causative gene is the erythroid delta-aminolaevulinate synthase 2 gene (ALAS2) on Xp11.21. We report here a case of XLSA. The patient was a 20-year-old Korean man referred to our hospital under the impression of sideroblastic anemia (SA). Laboratory findings, including a peripheral blood smearand bone marrow study, were compatible with SA. The family history was not remarkable. Based on the early age of onset, we suspected a hereditary form of SA, particularly XLSA. Direct DNA sequencing of ALAS2 detected a hemizygous c.509G>A (R170H) mutation in exon 5 of the gene. The patient showed minimal response to pyridoxine treatment. To the best of our knowledge, this is the first case of genetically confirmed XLSA from a mutation in ALAS2 in Korea.

Reconstruction of a Skin Defect Following Excision of Basal Cell Carcinoma in the Nose by Labial - alar Transposition Flap / 대한피부과학회지

We report a case of nasal BCC in which the skin defect is reconstructed by a local labial-alar transposition flap. In nasal reconstruction, the local flap is the preferred methods. This flap has the advantage of a more acceptable scar, is easy to make, and less edematous than a superiorly based flap. However, for defects larger than 1cm, this flap is not advisable and the defect has to be located adjacent to th nsolabial fold.