AIFM1 variants associated with auditory neuropathy spectrum disorder cause apoptosis due to impaired apoptosis-inducing factor dimerization / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Auditory neuropathy spectrum disorder (ANSD) represents a variety of sensorineural deafness conditions characterized by abnormal inner hair cells and/or auditory nerve function, but with the preservation of outer hair cell function. ANSD represents up to 15% of individuals with hearing impairments. Through mutation screening, bioinformatic analysis and expression studies, we have previously identified several apoptosis-inducing factor (AIF) mitochondria-associated 1 (AIFM1) variants in ANSD families and in some other sporadic cases. Here, to elucidate the pathogenic mechanisms underlying each AIFM1 variant, we generated AIF-null cells using the clustered regularly interspersed short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system and constructed AIF-wild type (WT) and AIF-mutant (mut) (p.‍T260A, p.‍R422W, and p.‍R451Q) stable transfection cell lines. We then analyzed AIF structure, coenzyme-binding affinity, apoptosis, and other aspects. Results revealed that these variants resulted in impaired dimerization, compromising AIF function. The reduction reaction of AIF variants had proceeded slower than that of AIF-WT. The average levels of AIF dimerization in AIF variant cells were only 34.5%‍‒‍49.7% of that of AIF-WT cells, resulting in caspase-independent apoptosis. The average percentage of apoptotic cells in the variants was 12.3%‍‒‍17.9%, which was significantly higher than that (6.9%‍‒‍7.4%) in controls. However, nicotinamide adenine dinucleotide (NADH) treatment promoted the reduction of apoptosis by rescuing AIF dimerization in AIF variant cells. Our findings show that the impairment of AIF dimerization by AIFM1 variants causes apoptosis contributing to ANSD, and introduce NADH as a potential drug for ANSD treatment. Our results help elucidate the mechanisms of ANSD and may lead to the provision of novel therapies.

Expression of AIF, PARP, and miRNAs MIR-145, MIR-210, and MIR-486 associated with apoptosis in the corpus cavernosum of rats subjected to chronic alcoholism model / Expresión de AIF, PARP y miRNAs MIR-145, MIR-210 y MIR-486 asociados con apoptosis en el cuerpo cavernoso de ratas sometidas a modelo de alcoholismo crónico

SUMMARY: Previous studies from our group described the consequences of using ethanol on penile erection. Nevertheless, the molecular mechanisms surrounding microRNAs, apoptosis process and their relationship with erectile dysfunction associated with alcohol consumption are still poorly understood. The objective of this analysis was to evaluate the mechanism of apoptosis by the expression of AIF and PARP, as well as their regulatory microRNAs: miR-145, miR-210 and miR-486, in the corpus cavernosum of rats submitted to a semivoluntary alcoholism model. For this study 24 Wistar rats were divided into two groups: control (C) and treated with 20 % ethanol (A) for seven weeks. The corpus cavernosum samples were prepared for immunohistochemical analysis of AIF and PARP protein expression, and microRNAs miR-145, miR-210, miR-486 gene expression in cavernous tissue was performed by real time PCR. The immunohistochemical analysis showed little nuclear positive labeling for the protein PARP and AIF in the corpus cavernosum of control and ethanol treated animals. After analysis of miR-145, -210 and -486 microRNA expression in the 12 animals studied, no results were found with significant statistical difference between the control and alcoholized groups. The expression of AIF and PARP and their regulatory microRNAs involved in apoptotic process (miR-145, miR-210 and miR-486) were not altered in the corpus cavernosum of rats submitted to semivoluntary alcoholism.

RESUMEN: Estudios previos de nuestro grupo describieron las consecuencias del uso de etanol en la erección del pene. Sin embargo, los mecanismos moleculares que rodean a los microARN, el proceso de apoptosis y su relación con la disfunción eréctil asociada con el consumo de alcohol aún no se conocen bien. El objetivo de este análisis fue evaluar el mecanismo de apoptosis mediante la expresión de AIF y PARP, así como sus microARN reguladores: miR-145, miR-210 y miR-486, en el cuerpo cavernoso de ratas sometidas a un modelo de alcoholismo semivoluntario. Se dividieron 24 ratas Wistar en dos grupos: control (C) grupo de ratas tratadas con etanol al 20 % (A) durante siete semanas. Las muestras del cuerpo cavernoso se prepararon para el análisis inmunohistoquímico de la expresión de la proteína AIF y PARP, y la expresión del gen microRNAs miR-145, miR-210, miR-486 en tejido cavernoso se realizó por PCR en tiempo real. El análisis inmunohistoquímico mostró escaso etiquetado nuclear positivo para la proteína PARP y AIF en el cuerpo cavernoso de los animales de control y tratados con etanol. Después del análisis de la expresión de microARN miR-145, -210 y -486 no se encontraron resultados con diferencias estadísticas significativas entre los grupos control y alcoholizados. La expresión de AIF y PARP y sus microARN reguladores involucrados en el proceso apoptótico (miR-145, miR-210 y miR-486) no se alteraron en el cuerpo cavernoso de las ratas sometidas a alcoholismo semivoluntario.

AIF, PARP-1 and MicroRNA-9 expression in cerebral ischemia associated to alcoholism experimental model / Expresión de AIF, PARP-1 y MicroRNA-9 de isquemia cerebral asociado a un modelo experimental de alcoholismo

The chronic consumption of alcohol causes a worsening of the events that follow the cerebral ischemia. These events are regulated through the expression of several genes and microRNAs. The aimof this work was To analyze and describe the expression profile of PARP and AIF and miRNA-9 proteins in rats submitted to focal cerebral ischemia, associated or not with chronic alcoholism model. Methods: Twenty adult Wistar rats, subdivided into: control; ischemic; alcoholic and ischemic / alcoholized for immunohistochemical analysis and miRNA-9 gene expression. Results: There was a reduction in the protein expression of PARP-1 and a positive marking for AIF in the ischemic / alcoholized group. The miRNA-9 did not obtain significant expression. The association of ischemia with chronic alcohol use promoted a tendency to low expression of miRNA-9, low expression of PARP-1 and high expression of AIF, indicating an interference in the protective effect of miRNA-9 be observed in the other groups.

El consumo crónico de alcohol provoca un empeoramiento de los eventos que siguen a la isquemia cerebral. Estos eventos están regulados a través de la expresión de varios genes y microRNA. El objetivo de este trabajo fue analizar y describir el perfil de expresión de las proteínas PARP y AIF y microRNA-9 en ratas sometidas a isquemia cerebral focal, asociadas o no, con el modelo de alcoholismo crónico. Veinte ratas Wistar adultas se dividieron en: grupo control, isquémico alcohólico, e isquémico / alcoholizado para análisis inmunohistoquímico y expresión de genes microRNA-9. Resultados: Hubo una reducción en la expresión de proteínas de PARP-1 y un marcado positivo para AIF en el grupo isquémico / alcoholizado. No se observó una expresión significativa en el microRNA-9. La asociación de la isquemia con el consumo crónico de alcohol promovió una tendencia a la baja expresión de microRNA-9, baja expresión de PARP1 y alta expresión de AIF, lo que indica una interferencia en el efecto protector de microRNA-9 en los otros grupos.

Long non-coding RNA HOTAIR promotes UVB-induced apoptosis and inflammatory injury by up-regulation of PKR in keratinocytes

Excessive exposure to ultraviolet (UV) rays can cause damage of the skin and may induce cancer, immunosuppression, photoaging, and inflammation. The long non-coding RNA (lncRNA) HOX antisense intergenic RNA (HOTAIR) is involved in multiple human biological processes. However, its role in UVB-induced keratinocyte injury is unclear. This study was performed to investigate the effects of HOTAIR in UVB-induced apoptosis and inflammatory injury in human keratinocytes (HaCaT cells). Quantitative real-time polymerase chain reaction was performed to analyze the expression levels of HOTAIR, PKR, TNF-α, and IL-6. Cell viability was measured using trypan blue exclusion method and cell apoptosis using flow cytometry and western blot. ELISA was used to measure the concentrations of TNF-α and IL-6. Western blot was used to measure the expression of PKR, apoptosis-related proteins, and PI3K/AKT and NF-κB pathway proteins. UVB induced HaCaT cell injury by inhibiting cell viability and promoting cell apoptosis and expressions of IL-6 and TNF-α. UVB also promoted the expression of HOTAIR. HOTAIR suppression increased cell viability and decreased apoptosis and expression of inflammatory factors in UVB-treated cells. HOTAIR also promoted the expression of PKR. Overexpression of HOTAIR decreased cell viability and increased cell apoptosis and expression of inflammatory factors in UVB-treated cells by upregulating PKR. Overexpression of PKR decreased cell viability and promoted cell apoptosis in UVB-treated cells. Overexpression of PKR activated PI3K/AKT and NF-κB pathways. Our findings identified an essential role of HOTAIR in promoting UVB-induced apoptosis and inflammatory injury by up-regulating PKR in keratinocytes.

Incorporación de paciente virtual en portafolio de estudiantes de medicina de pregrado / Introduction of virtual patients to clinical case portfolios for undergraduate medical students

Background: In 2007, a Clinical-Case-Portfolio (CCP) was introduced as a new assessment instrument for fourth grade undergraduate medical students. Since then, several changes have been implemented such as reduction on the number of clinical cases, peer review and the introduction of virtual patient to the portfolio. Aim: To describe the virtual patient model incorporated to the CCP and assess the perception of this change and its effects on the performance of undergraduate students. Material and Methods: Virtual patients were implemented based on prototype clinical cases with specific syndromes. Students’ perceptions about CCP before and after the introduction of virtual patients were evaluated using a validated questionnaire that was answered voluntarily and anonymously. Results: Overall perception of CCP significantly improved after the incorporation of virtual patients (97.1 ± 24.9 and 111.3 ± 25.7 points; 57.8 and 66.2% respectively). The same improvements were observed for the domains “Student Learning”, “Organization and Evaluation”, “Teaching Methodology” and “Integration”. In both years, students obtained high grades in CCP evaluations. However CCP grades were not significantly correlated with integrated final grades. Conclusions: The incorporation of virtual patients improved undergraduate students’ perception of CCP.

Perioperative myocardial infarction in patients undergoing myocardial revascularization surgery / Infarto do miocárdio perioperatório em pacientes submetidos à cirurgia de revascularização miocárdica

Introduction: Perioperative myocardial infarction adversely affects the prognosis of patients undergoing coronary artery bypass graft and its diagnosis was hampered by numerous difficulties, because the pathophysiology is different from the traditional instability atherosclerotic and the clinical difficulty to be characterized. Objective: To identify the frequency of perioperative myocardial infarction and its outcome in patients undergoing coronary artery bypass graft. Methods: Retrospective cohort study performed in a tertiary hospital specialized in cardiology, from May 01, 2011 to April 30, 2012, which included all records containing coronary artery bypass graft records. To confirm the diagnosis of perioperative myocardial infarction criteria, the Third Universal Definition of Myocardial Infarction was used. Results: We analyzed 116 cases. Perioperative myocardial infarction was diagnosed in 28 patients (24.1%). Number of grafts and use and cardiopulmonary bypass time were associated with this diagnosis and the mean age was significantly higher in this group. The diagnostic criteria elevated troponin I, which was positive in 99.1% of cases regardless of diagnosis of perioperative myocardial infarction. No significant difference was found between length of hospital stay and intensive care unit in patients with and without this complication, however patients with perioperative myocardial infarction progressed with worse left ventricular function and more death cases. Conclusion: The frequency of perioperative myocardial infarction found in this study was considered high and as a consequence the same observed average higher troponin I, more cases of worsening left ventricular function and death. .

Introdução: O infarto do miocárdio perioperatório afeta negativamente o prognóstico dos pacientes submetidos à cirurgia de revascularização do miocárdio e seu diagnóstico esbarra em inúmeras dificuldades, pois a fisiopatologia é diferente da tradicional instabilidade aterosclerótica e o quadro clínico de difícil caracterização. Objetivo: Identificar a frequência de infarto do miocárdio perioperatório e seu desfecho em pacientes submetidos à cirurgia de revascularização do miocárdio. Métodos: Coorte retrospectiva realizada em hospital terciário especializado em cardiologia, de 1 de maio de 2011 a 30 de abril de 2012, que incluiu todos os prontuários contendo registros de cirurgia de revascularização do miocárdio. Para confirmação diagnóstica do infarto do miocárdio perioperatório, foram utilizados os critérios da Third Universal Definition of Myocardial Infarction Resultados: Foram analisados 116 casos. Foi diagnosticado infarto do miocárdio perioperatório em 28 pacientes (24,1%). Número de enxertos e utilização e tempo de circulação extracorpórea foram fatores associados a este diagnóstico e a média de idade foi significativamente mais elevada neste grupo. O critério diagnóstico elevação de troponina I foi positivo em 99,1% dos casos, independentemente do diagnóstico de infarto do miocárdio perioperatório. Não foi encontrada diferença significativa entre tempo de internação hospitalar e em unidade de terapia intensiva nos grupos com e sem esta complicação, porém pacientes com infarto do miocárdio perioperatório evoluíram com pior função ventricular esquerda e mais casos de óbito. Conclusão: A frequência de infarto do miocárdio perioperatório encontrada neste trabalho foi considerada alta e como consequência do mesmo observou-se média mais elevada de troponina I, mais casos de piora da função ventricular esquerda e óbito. .

Leishmania, Babesia and Ehrlichia in urban pet dogs: co-infection or cross-reaction in serological methods?

INTRODUCTION: The present study was designed to assess the occurrence of co-infection or cross-reaction in the serological techniques used for detecting the anti-Leishmania spp., -Babesia canis vogeli and -Ehrlichia canis antibodies in urban dogs from an area endemic to these parasites. METHODS: The serum samples from dogs were tested for the Babesia canis vogeli strain Belo Horizonte antigen and Ehrlichia canis strain São Paulo by immunofluorescence antibody test (IFAT) and by anti-Leishmania immunoglobulin G (IgG) antibody detection to assess Leishmania infection. We used the following four commercial kits for canine visceral leishmaniasis: ELISA, IFAT, Dual Path Platform (DPP) (Bio Manguinhos(r)/FIOCRUZ/MS) and a rK39 RDT (Kalazar Detect Canine Rapid Test; Inbios). RESULTS : Of 96 serum samples submitted to serological assays, 4 (4.2%) were positive for Leishmania as determined by ELISA; 12 (12.5%), by IFAT; 14 (14.6%) by rK39 RDT; and 20 (20.8%), by DPP. Antibodies against Ehrlichia and Babesia were detected in 23/96 (23.9%) and 30/96 (31.2%) samples, respectively. No significant association was identified between the results of tests for detecting Babesia or Ehrlichia and those for detecting Leishmania (p-value>0.05). CONCLUSIONS: In the present study, we demonstrated co-infection with Ehrlichia or Babesia and Leishmania in dogs from Minas Gerais (Brazil); we also found that the serological tests that were used did not cross-react. .

The proapoptotic activity of C-terminal domain of apoptosis-inducing factor (AIF) is separated from its N-terminal

Apoptosis-inducing factor (AIF) is a mitochondrial flavoprotein that mediates both NADH-oxidizing and caspase-independent apoptosis. Further, the proapoptotic activity of AIF is located in the C-terminus of AIF, although the precise minimum sequence responsible for apoptosis induction remains to be investigated. In the present study, we generated two truncated AIFs, AIFΔ1-480-FLAG, which is a FLAG-tagged C-terminal peptide comprising amino acids from 481 to 613, and AIF360-480 containing amino acids from 360 to 480 of AIF. We used confocal microscopy to demonstrate that both the truncated proteins are expressed and located in the cytoplasm of transfected cells. AIFΔ1-480 but not AIF360-480 induces apoptosis in transfected cells. We also found that the expression of AIFΔ1-480 could initiate the release of cytochrome c from the mitochondria. The suppression of caspase-9 via siRNA blocked the proapoptotic activity of AIFΔ1-480. Therefore, AIFΔ 1-480 is sufficient for inducing caspase-9-dependent apoptotic signaling, probably by promoting the release of cytochrome c. At last, we generated a chimeric immuno-AIFΔ 1-480 protein, which comprised an HER2 antibody, a Pseudomonas exotoxin A translocation domain and AIFΔ 1-480. Human Jurkat cells transfected with the immuno-AIFΔl-480 gene could express and secrete the chimeric protein, which selectively recognize and kill HER2-overexpressing tumor cells. Our study demonstrates the feasibility of the immuno-AIFΔl-480 gene as a novel approach to treating HER2-overexpressing cancers.