Graphene Oxide and Reduced Graphene Oxide Exhibit Cardiotoxicity Through the Regulation of Lipid Peroxidation, Oxidative Stress, and Mitochondrial Dysfunction.

OBJECTIVE: Graphene has been widely used for various biological and biomedical applications due to its unique physiochemical properties. This study aimed to evaluate the cardiotoxicity of graphene oxide (GO) and reduced GO (rGO) in vitro and in vivo, as well as to investigate the underlying toxicity mechanisms. METHODS: GO was reduced by gamma irradiation to prepare rGO and then characterized by UV/visible light absorption spectroscopy. Rat myocardial cells (H9C2) were exposed to GO or rGO with different absorbed radiation doses. The in vitro cytotoxicity was evaluated by MTT assay, cell apoptosis assay, and lactate dehydrogenase (LDH) activity assay. The effects of GO and rGO on oxidative damage and mitochondrial membrane potential were also explored in H9C2 cells. For in vivo experiments, mice were injected with GO or rGO. The histopathological changes of heart tissues, as well as myocardial enzyme activity and lipid peroxidation indicators in heart tissues were further investigated. RESULTS: rGO was developed from GO following different doses of gamma irradiation. In vitro experiments in H9C2 cells showed that compared with control cells, both GO and rGO treatment inhibited cell viability, promoted cell apoptosis, and elevated the LDH release. With the increasing radiation absorbed dose, the cytotoxicity of rGO gradually increased. Notably, GO or rGO treatment increased the content of ROS and reduced the mitochondrial membrane potential in H9C2 cells. In vivo experiments also revealed that GO or rGO treatment damaged the myocardial tissues and changed the activities of several myocardial enzymes and the lipid peroxidation indicators in the myocardial tissues. CONCLUSION: GO exhibited a lower cardiotoxicity than rGO due to the structure difference, and the cardiotoxicity of GO and rGO might be mediated by lipid peroxidation, oxidative stress, and mitochondrial dysfunction.

miRNAS in cardiovascular diseases: potential biomarkers, therapeutic targets and challenges.

Cardiovascular diseases (CVD) are the leading cause of morbidity and mortality in the world. Although considerable progress has been made in the diagnosis, treatment and prognosis of CVD, there is still a critical need for novel diagnostic biomarkers and new therapeutic interventions to decrease the incidence of this disease. Recently, there is increasing evidence that circulating miRNAs (miRNAs), i.e. endogenous, stable, single-stranded, short, non-coding RNAs, can be used as diagnostic biomarkers for CVD. Furthermore, miRNAs represent potential novel therapeutic targets for several cardiovascular disorders. In this review we provides an overview of the effects of several CVD; including heart failure, acute myocardial infarction, arrhythmias and pulmonary hypertension; on levels of circulating miRNAs. In addition, the use of miRNA as therapeutic targets is also discussed, as well as challenges and recommendations in their use in the diagnosis of CVD.

Analysis of metabolism-related indicators and MTHFR gene polymorphism in patients with H-type hypertension.

BACKGROUND: This study aims to analyze the polymorphism of the methylene tetrahydrofolate reductase (MTHFR) gene in patients with hypertension, and explore the correlation between H-type hypertension and metabolic biochemical indicators such as homocysteine (Hcy). METHODS: One hundred patients with H-type hypertension and 100 patients with common hypertension were selected as the study subjects. Plasma Hcy and blood lipids, blood glucose, and other biochemical indicators were detected in the two groups. Then, the polymorphism of the MTHFR gene was compared between these two groups. RESULTS: Hcy, uric acid (UA) and creatinine (Cr) levels in the H-type hypertension group were significantly higher than those of the common hypertension group (t=4.832-14.989, P<0.05). The T allele was predominant in the MTHFR 677C/T genotype frequency distribution in the H-type hypertension group, while the C allele was predominantly in the frequency distribution in the common hypertension group (P<0.05). CONCLUSIONS: High levels of Hcy, UA and Cr are closely related to the occurrence of H-type hypertension. Homozygous mutant TT genotype of 677C/T of the MTHFR gene may be an important genetic factor of H-type hypertension.

[Cluster analysis in micrangium detection in malignant nasal and paranasal sinus tumor].

OBJECTIVE: To study the application of cluster analysis in micrangium detection in malignant nasal and paranasal sinus tumor. METHODS: Microvessel density (MVD) counting and cluster analysis were used to detect the micrangium in patients with malignant nasal and paranasal sinus tumor to assess the association between the malignancy and MVD. RESULTS: According to cluster analysis, the MVD counting could be clustered into two groups, and the MVD showed significant differences between the tumor tissues, adjacent normal tissue and the control group (P<0.01), a result consistent with that by analysis of variance of the MVD. CONCLUSION: Cluster analysis can be used in clustering of MVD counting in malignant nasal and paranasal sinus tumor to simplify MVD counting, and offers an important analytic method for micrangium analysis in tumors.

[Recombinant adeno-associated virus conducted NgR(DN) enhances axonal regeneration of optic nerve after trauma: experiment with rats].

OBJECTIVE: To investigate the effect of recombinant adeno-associated virus conducted NgRDN on the axonal regeneration of optic nerve after trauma. METHODS: Two kinds of adeno-associated virus (AAV), AAV-NgRDN-EGFP containing dominant negative form of Nogo receptor and enhanced green fluorescent protein (EGFP) and rAAV-NgR-EGFP containing Nogo-66 receptor (NgR) and EGFP, were constructed. 45 adult Wistar male rats were randomly divided into three equal groups, all with both eyes as experimental eyes: Groups A, B, and C to undergo injection of rAAV-EGFP, rAAV-NgR-EGFP, and rAAV-NgRDN-EGFP respectively into the vitreous; and each group was subdivided into 3 equal subgroups: subgroups 1 underwent injection of rAAV only, subgroups 2 underwent injection of rAAV and lens trauma, and subgroups 3 underwent injection of rAAV and zymosan. The rats in the Subgroups A2, B2, and C2 underwent. Crush of the optic nerve 2 mm behind the eyeball with optic nerve forceps 3 weeks after the injection. Four days after the crush the right eyes were taken out and the retinal explants were cultured in 2 kinds of culture fluid: with or without myelin. The growth of axons at the edge of retinal explants was observed by immunofluorescent staining with betaIII tubulin. Two weeks after the crush the other eyes were taken out to isolate the optic nerves. Immunofluorescence assay was used to detect the expression of growth associated protein-43 (GAP-43) of optic nerve. The axonal regeneration of optic nerve was observed. RESULTS: betaIII tubulin staining showed that on the condition of culture fluid without myelin both rAAV-NgR-EGFP and rAAV-NgRDN-EGFP showed no effects on the axonal regeneration of retinal ganglion cells (RGCs). However, on the condition of culture fluid with myelin the count of axonal regeneration and the length of regenerated axons of Group B were (13+/-4) and (36 microm+/-4 microm), both significantly lower than those of Group A [(21+/-4) and (83 microm+/-11 microm) respectively, both P<0.01]. There were not significant differences in count of axonal regeneration and length of regenerated axons between Subgroups C1 and A1. The count of axonal regeneration and length of regenerated axons of Subgroups C2 were (317+/-45) and (508 microm+/-44 microm), both significantly higher than those of Subgroup C3 [(238+/-30) and (365 microm+/-48 microm) respectively, both P<0.01], and the values of both Subgroups C2 and C3 were significantly higher than those of Subgroups A2 and A3. The GAP43-positive area in the optic nerve of Group C was significantly larger than that of Group A (P<0.01), and that of Group B was significantly smaller than that of Group A (P<0.01). The GAP43-positive area in the optic nerve of Subgroup A2 was (18.71+/-1.72)x100 microm2, significantly larger than that of Subgroup A3 [(12.75+/-1.02)x100 microm2, P<0.01], and that of Subgroup A3 was significantly larger than that of Subgroup A1 (P<0.01). There were not significant differences in the GAP43-positive area among the subgroups in Group B. CONCLUSION: Transfection of rAAV-NgRDN-EGFP into RGC in an activated status enhances axonal regeneration of optic nerve. NgRDN AAV can inhibit effectively the role of NgR.

[Expression and correlation of apoptosis-related gene c-IAP2 and caspase-4 in sinonasal squamous carcinoma].

OBJECTIVE: To examine the expression of apoptosis-related genes c-IAP2 and caspase-4 in sinonasal squamous carcinoma. To investigate the role and mechanism of the two apoptosis-related genes in nasal cavity and sinus squamons carcinoma. METHODS: Forty-one pathologically confirmed specimens of nasal cavity and sinus squamons carcinoma were subjected for immunohistochemical staining to analyze the expression of c-IAP2 and caspase-4, in addition 10 normal nasal mucosa were used as control. RESULTS: The positive rate of c-IAP2 in sinonasal squamons carcinoma was 87.8%, among which 14 cases were strongly stained(+ + +), 15 cases were stained(+ +), 7 cases were stained (+), only 5 cases were negative. In 10 normal control tissues, no case was stained(+ + +), 2 cases were stained (+ +), 3 cases were stained(+), the other 5 cases were negative. Higher level expression of c-IAP2 protein was detected more often in squamons carcinoma specimens than that in normal nasal mucosa. There was statistically significant difference between the two groups for the staining(P < 0.05). The expression of c-IAP2 was not correlated with clinical staging (P > 0.05), but there were positive correlation with clinical prognosis (P < 0.01) and pathological classification (P < 0.01); The positive rate of caspase-4 in nasal cavity and sinus squamons carcinoma was 58.5%, among which 4 cases were strongly stained (+ + +), 7 cases were stained (+ +), 13 case was stained(+), 17 cases were negative. The expression of caspase-4 protein was more deletion in squamons carcinoma specimens than that in control group, there was statistically significant difference between the two groups for the staining (P < 0.05). The expression of caspase-4 protein was negatively correlated with clinical prognosis (P < 0.01) and pathological classification ( P < 0.01), not correlated with clinical staging(P > 0.05). The expression of c-IAP2 was negativelly correlated with the experssion of caspase-4. CONCLUSIONS: The results indicates that in sinonasal squamous carcinoma, c-IAP2 is activated, while caspase-4 is restrained, the signal transduction pathway of apoptosis is arrested, leading to surviving of tumor cells, this maybe directly associated with the development of sinonasal squamons carcinoma, and with the failure of tumor trentment.