Hsa_circ_0007059 promotes apoptosis and inflammation in cardiomyocytes during ischemia by targeting microRNA-378 and microRNA-383.

Circular RNAs (circRNAs) are a class of non-coding RNA molecules that are associated with not only normal physiological functions but also various diseases, including cardiac diseases such as myocardial infarction (MI). The present study explored the potential role of circRNA_0007059 (circ_0007059) during MI pathogenesis using in vitro studies. Microarray and quantitative PCR analyses demonstrated elevated circ_0007059 expression and downregulated miR-378 and miR-383 expression in H2O2-treated mice cardiomyocytes and infarcted hearts of MI mouse model as compared those in relevant controls. Moreover, circ_0007059 knockdown improved cardiomyocyte viability after H2O2 treatment as revealed by the CCK-8 and colony formation assays. Flow cytometry and caspase activity assays demonstrated that circ_0007059 suppressed H2O2-induced cardiomyocyte apoptosis. Enzyme-linked immunosorbent assays and Western blotting revealed that inflammatory cytokine (interleukin-1ß, interleukin-18 and C-C motif chemokine ligand 5) expression was induced by H2O2 treatment and that circ_0007059 repressed H2O2-induced inflammation. Bioinformatics analyses and dual-luciferase reporter assays showed that circ_0000759 acts as a miR-378 and miR-383 sponge. Furthermore, the upregulation or suppression of miR-378 and miR-383 expression in H2O2-treated cardiomyocytes had similar effects on the apoptosis and inflammation of cardiomyocytes as that of circ_0007059 knockdown or overexpression, respectively. Additionally, lentiviral shRNA-circ_0007059 administration to mice with MI considerably reduced the size of infarcted regions and promoted cardiac activity. Collectively, our findings suggest that circ_0007059 expression is upregulated in mice cardiomyocytes in response to oxidative stress and cardiac tissues of MI mouse model, suggesting its involvement in the pathogenesis of MI by targeting miR-378 and miR-383.

Inhibiting Glucose Metabolism By miR-34a and miR-125b Protects Against Hyperglycemia-Induced Cardiomyocyte Cell Death. / A Inibição do Metabolismo da Glicose por miR-34a e miR-125b Protege contra a Morte Celular de Cardiomiócitos Causada por Hiperglicemia.

BACKGROUND: It is well-known that insulin resistance and hyperglycemia are important pathological causes for the development of diabetic cardiomyopathy (DCM). However, its precise molecular mechanisms in the pathogenesis of DCM remain unclear. OBJECTIVES: Recent studies reveal that microRNAs (miRNA) play essential roles in the pathogenesis of DCM. This project aimed to determine the roles of miR-34a and miR-125b in hyperglycemia-induced cardiomyocyte cell death. METHODS: Rat primary cardiomyocytes were isolated and exposed to normal and high concentrations of glucose. Cell viability was measured using MTT assay. Expressions of miR-34a and miR-125b were detected by qRT-PCR. Potential targets of miR-34a and miR-125b were predicted from www.Targetscan.org and validated from human heart tissues. A statistical significance of p<0.05 was considered. RESULTS: The present study shows that miR-34a and miR-125b are downregulated in a human diabetic heart. Moreover, in vitro data from rat primary cardiomyocytes showed that short-term high glucose treatment stimulates miR-34a and miR-125b expressions. Under high glucose, it was found that rat cardiomyocytes displayed increased intracellular glucose metabolism, and glucose uptake and lactate production were significantly increased. It was also found that the key glucose metabolic enzymes, Hexokinase 2 (HK2) and Lactate dehydrogenase-A (LDHA), were direct targets of miR-125b and miR-34a, respectively. Overexpression of miR-125b and miR-34a could prevent hyperglycemia-induced cardiomyocyte cell death. Finally, the restoration of HK2 and LDHA in miR-125b and miR-34a overexpressed cardiomyocytes recovered the cardiomyocytes' sensitivity to hyperglycemia. CONCLUSION: Our results proposed a molecular mechanism for the microRNA-mediated diabetic cardiovascular protection and will contribute to developing treatment strategies for diabetes-associated cardiovascular dysfunction.

FUNDAMENTO: É sabido que a resistência à insulina e a hiperglicemia são causas patológicas importantes no desenvolvimento de cardiomiopatia diabética (CMD). Entretanto, seus mecanismos moleculares precisos na patogênese da CMD ainda não estão claros. OBJETIVOS: Estudos recentes revelam que os microRNAs (miRNAs) desempenham papéis essenciais na patogênese da CMD. Este projeto tem o objetivo de determinar os papéis de miR-34a e miR-125b na morte celular de cardiomiócitos causada por hiperglicemia. MÉTODOS: Cardiomiócitos primários de ratos foram isolados e expostos a concentrações de glicose normais e altas. A viabilidade das células foi medida utilizando-se o ensaio MTT. As expressões de miR-34a e miR-125b foram detectadas por qRT-PCR. Alvos potenciais de miR-34a e miR-125b foram previstos pelo www.Targetscan.org, e validados a partir de tecidos cardíacos humanos. Um p<0,05 foi considerado significância estatística. RESULTADOS: Demonstra-se neste estudo que o miR-34a e o miR-125b têm resposta celular reduzida no coração humano diabético. Além disso, os dados in vitro de cardiomiócitos primários de ratos demonstraram que o tratamento com glicose alta em curto prazo estimula a expressão de miR-34a e miR-125b. Demonstrou-se que, em condições de glicose alta, os cardiomiócitos de ratos apresentaram metabolismo de glicose intracelular, e a captação de glicose e a produção de lactato aumentaram significativamente. Foi identificado que as principais enzimas metabólicas da glicose, hexoquinase 2 (HK2) e lactato desidrogenase-A (LDHA) eram alvos diretos de miR-125b e miR-34a, respectivamente. A superexpressão de miR-125b e miR-34a poderia evitar a morte de celular de cardiomiócitos causada por hiperglicemia. Por fim, a recuperação de HK2 e LDHA em cardiomiócitos com superexpressão de miR-125b e miR-34a restaurou a sensibilidade de cardiomiócitos à hiperglicemia. CONCLUSÕES: Nossos resultados propõem um mecanismo molecular para proteção cardiovascular diabética mediada por microRNA e contribuirão para o desenvolvimento de estratégias de tratamento de disfunção cardiovascular associada a diabetes.

A Inibição do Metabolismo da Glicose por miR-34a e miR-125b Protege contra a Morte Celular de Cardiomiócitos Causada por Hiperglicemia / Inhibiting Glucose Metabolism By miR-34a and miR-125b Protects Against Hyperglycemia-Induced Cardiomyocyte Cell Death

Resumo Fundamento: É sabido que a resistência à insulina e a hiperglicemia são causas patológicas importantes no desenvolvimento de cardiomiopatia diabética (CMD). Entretanto, seus mecanismos moleculares precisos na patogênese da CMD ainda não estão claros. Objetivos: Estudos recentes revelam que os microRNAs (miRNAs) desempenham papéis essenciais na patogênese da CMD. Este projeto tem o objetivo de determinar os papéis de miR-34a e miR-125b na morte celular de cardiomiócitos causada por hiperglicemia. Métodos: Cardiomiócitos primários de ratos foram isolados e expostos a concentrações de glicose normais e altas. A viabilidade das células foi medida utilizando-se o ensaio MTT. As expressões de miR-34a e miR-125b foram detectadas por qRT-PCR. Alvos potenciais de miR-34a e miR-125b foram previstos pelo www.Targetscan.org, e validados a partir de tecidos cardíacos humanos. Um p<0,05 foi considerado significância estatística. Resultados: Demonstra-se neste estudo que o miR-34a e o miR-125b têm resposta celular reduzida no coração humano diabético. Além disso, os dados in vitro de cardiomiócitos primários de ratos demonstraram que o tratamento com glicose alta em curto prazo estimula a expressão de miR-34a e miR-125b. Demonstrou-se que, em condições de glicose alta, os cardiomiócitos de ratos apresentaram metabolismo de glicose intracelular, e a captação de glicose e a produção de lactato aumentaram significativamente. Foi identificado que as principais enzimas metabólicas da glicose, hexoquinase 2 (HK2) e lactato desidrogenase-A (LDHA) eram alvos diretos de miR-125b e miR-34a, respectivamente. A superexpressão de miR-125b e miR-34a poderia evitar a morte de celular de cardiomiócitos causada por hiperglicemia. Por fim, a recuperação de HK2 e LDHA em cardiomiócitos com superexpressão de miR-125b e miR-34a restaurou a sensibilidade de cardiomiócitos à hiperglicemia. Conclusões: Nossos resultados propõem um mecanismo molecular para proteção cardiovascular diabética mediada por microRNA e contribuirão para o desenvolvimento de estratégias de tratamento de disfunção cardiovascular associada a diabetes.

Abstract Background: It is well-known that insulin resistance and hyperglycemia are important pathological causes for the development of diabetic cardiomyopathy (DCM). However, its precise molecular mechanisms in the pathogenesis of DCM remain unclear. Objectives: Recent studies reveal that microRNAs (miRNA) play essential roles in the pathogenesis of DCM. This project aimed to determine the roles of miR-34a and miR-125b in hyperglycemia-induced cardiomyocyte cell death. Methods: Rat primary cardiomyocytes were isolated and exposed to normal and high concentrations of glucose. Cell viability was measured using MTT assay. Expressions of miR-34a and miR-125b were detected by qRT-PCR. Potential targets of miR-34a and miR-125b were predicted from www.Targetscan.org and validated from human heart tissues. A statistical significance of p<0.05 was considered. Results: The present study shows that miR-34a and miR-125b are downregulated in a human diabetic heart. Moreover, in vitro data from rat primary cardiomyocytes showed that short-term high glucose treatment stimulates miR-34a and miR-125b expressions. Under high glucose, it was found that rat cardiomyocytes displayed increased intracellular glucose metabolism, and glucose uptake and lactate production were significantly increased. It was also found that the key glucose metabolic enzymes, Hexokinase 2 (HK2) and Lactate dehydrogenase-A (LDHA), were direct targets of miR-125b and miR-34a, respectively. Overexpression of miR-125b and miR-34a could prevent hyperglycemia-induced cardiomyocyte cell death. Finally, the restoration of HK2 and LDHA in miR-125b and miR-34a overexpressed cardiomyocytes recovered the cardiomyocytes' sensitivity to hyperglycemia. Conclusion: Our results proposed a molecular mechanism for the microRNA-mediated diabetic cardiovascular protection and will contribute to developing treatment strategies for diabetes-associated cardiovascular dysfunction.

Oxidized Low Density Lipoprotein-Induced Atherogenic Response of Human Umbilical Vascular Endothelial Cells (HUVECs) was Protected by Atorvastatin by Regulating miR-26a-5p/Phosphatase and Tensin Homolog (PTEN).

BACKGROUND Atherosclerosis is a chronic and multifactorial disease, and it is the main reason of coronary heart disease, cerebral infarction, and peripheral vascular disease, which leads to the formation of lesions in arterial blood vessels. Our study aimed to explore the protective effect and its underlying mechanism of atorvastatin (ATV) on oxidized low-density lipoprotein (ox-LDL)-induced atherosclerosis. MATERIAL AND METHODS Human umbilical vascular endothelial cells (HUVECs) were cultured and pretreated with ox-LDL to establish an in vitro atherosclerotic cell model. Cell Counting Kit-8 (CCK-8) assay, TUNEL staining, and Transwell assay were used to detect the cell activity, apoptosis, and migration in HUVECs. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot were applied to measure the mRNA and protein expressions of adhesion-related genes in HUVECs. RESULTS Pretreated with 100 mg/L ox-LDL resulted in a 57.23% decrease of cell viability and 81.09% increase of apoptotic injury in HUVECs compare to the control. Meanwhile, ox-LDL pretreatment increased the cell migration and the expression of miR-26a-5p in HUVECs. ATV treatment could effectively reverse the cellular damage induced by ox-LDL, decrease the release of adhesion-related molecules, and downregulate the expression of miR-26a-5p by 44.79% in HUVECs. Moreover, phosphatase and tensin homolog (PTEN) was demonstrated to be the target gene of miR-26a-5p. CONCLUSIONS Our results highlight that ATV protects against ox-LDL-induced downregulation of cell viability, upregulation of cell apoptosis, migration, as well as the release of adhesion-related molecules in HUVECs through the miR-26a-5p/PTEN axis. This study provides new insights into the underlying mechanism of ATV therapeutic potential in atherosclerosis, and also provides a new strategy for the treatment of atherosclerosis.

Osteochondroma in the lumbar intraspinal canal causing nerve root compression.

Osteochondromas, which are benign bone tumors that usually develop on long bones, tubular bones, are rarely found in the spine. If they are located in the spinal canal, they may cause nerve root or spinal cord compression, which is a rare but potentially catastrophic manifestation of osteochondromas. In this article, we report a case of a 38-year-old man who presented with low back pain, paresthesia, and weakness of the right lower extremity aggravating gradually for 5 months. No family history of this disease can be traced. The L4-L5 level computed tomography scan showed an abnormal bony protrusion arising from the right interior wall of L5 right lamina toward the intraspinal canal. The protrusion compressed the L5 nerve root severely. T2-weighted magnetic resonance imaging (MRI) of the same level revealed that the L5 nerve root and spinal dura mater were notably compressed by the intraspinal extradural exostosis attached to the right lamina of L5. Considering differential diagnosis, lumbar facet synovial cysts must be excluded as they can also cause myeloradiculopathy with the similar mechanism. The tumor, approximately 6x7x11 mm, was identified after laminectomy of the L5 laminae. Postoperative histopathologic examination confirmed our hypothesis of benign osteochondroma. Postoperatively, the patient recovered rapidly in neurological function and was free of symptoms. Surgery is essential to this rare case. Computed tomography and MRI are helpful for the preoperatively precise indication of tumor extent and its relationships with the adjacent.