Epididymal white adipose tissue promotes angiotensin II-induced cardiac fibrosis in an exosome-dependent manner.

Cardiac fibrosis is a process characterized by extracellular matrix accumulation leading to myocardial dysfunction. Angiotensin II (Ang II) has been shown to play an important role in the pathogenesis of cardiac fibrosis. However, the underlying mechanisms are not well established. Dysfunction of adipose tissue has been shown to promote remote organ injury, but its role in Ang II-induced cardiac remodeling is still unclear. In this study, we demonstrated that epididymal white adipose tissue (eWAT) promoted Ang II-induced cardiac fibrosis and subsequent cardiac dysfunction in an exosome-dependent manner. Both eWAT removal and administration of an inhibitor of exosome biogenesis strongly attenuated Ang II-induced abnormalities. Moreover, exosomes isolated from Ang II-stimulated adipocytes promoted cardiac fibroblasts (CFs) activity. A mechanistic study identified that the miR-23a-3p level was significantly increased in exosomes derived from Ang II-challenged adipocytes and serum exosomes from Ang II-infused mice. Importantly, tail vein injection of ago-miR-23a-3p caused cardiac fibrosis and dysfunction, while antago-miR-23a-3p inhibited Ang II-induced cardiac fibrosis. Bioinformatics analysis and further validation experiments revealed that RAP1 is a direct downstream target of miR-23a-3p, and overexpression of RAP1 reversed the profibrotic effect of miR-23a-3p. Taken together, these findings elucidated the role of eWAT in Ang II-induced myocardial fibrosis and indicated that adipocyte-derived exosomes mediate pathologic communication between dysfunctional adipose tissue and the heart by transporting miR-23a-3p into CFs, transforming fibroblasts into myofibroblasts and promoting excessive collagen deposition by targeting RAP1. Prevention of abnormal adipocyte exosome production, inhibition of miR-23a-3p biogenesis, and treatment with a miR-23a-3p antagonist are novel strategies for treating cardiac fibrosis.

Combination therapy of molecular hydrogen and hyperoxia improves survival rate and organ damage in a zymosan-induced generalized inflammation model.

Multiple organ dysfunction syndrome (MODS) is a leading cause of mortality in critically ill patients. Hyperoxia treatment may be beneficial to critically ill patients. However, the clinical use of hyperoxia is hindered as it may exacerbate organ injury by increasing reactive oxygen species (ROS). Hydrogen gas (H2) exerts a therapeutic antioxidative effect by selectively reducing ROS. Combination therapy of H2 and hyperoxia has previously been shown to significantly improve survival rate and organ damage extent in mice with polymicrobial sepsis. The aim of the present study was to investigate whether combination therapy with H2 and hyperoxia could improve survival rate and organ damage in a zymosan (ZY)-induced generalized inflammation model. The results showed that the inhalation of H2 (2%) or hyperoxia (98%) alone improved the 14-day survival rate of ZY-challenged mice from 20 to 70 or 60%, respectively. However, combination therapy with H2 and hyperoxia could increase the 14-day survival rate of ZY-challenged mice to 100%. Furthermore, ZY-challenged mice showed significant multiple organ damage characterized by increased serum levels of aspartate transaminase, alanine transaminase, blood urea nitrogen and creatinine, as well as lung, liver and kidney histopathological scores at 24 h after ZY injection. These symptoms where attenuated by H2 or hyperoxia alone; however, combination therapy with H2 and hyperoxia had a more marked beneficial effect against lung, liver and kidney damage in ZY-challenged mice. In addition, the beneficial effects of this combination therapy on ZY-induced organ damage were associated with decreased serum levels of the oxidative product 8-iso-prostaglandin F2α, increased activity of superoxide dismutase and reduced levels of the proinflammatory cytokines high-mobility group box 1 and tumor necrosis factor-α. In conclusion, combination therapy with H2 and hyperoxia provides enhanced therapeutic efficacy against multiple organ damage in a ZY-induced generalized inflammation model, suggesting the potential applicability of H2 and hyperoxia in the therapy of conditions associated with inflammation-related MODS.

A rare case of tumor-mimicking primary angiitis of the central nervous system.

Primary angiitis of the central nervous system (PACNS) is a rare, but severe vascular disease. The present study reports the case of a 42-year-old male who developed PACNS. Magnetic resonance imaging (MRI) scans initially led to a misleading diagnosis of malignant glioma, and surgery was performed. The mass was resected, and a pathological examination confirmed a cerebral vasculitis. Single therapy with high doses of steroid did not improve the patient's condition, while a subsequent lesion appeared on the opposite side one year later. Combined therapy with methylprednisone and cyclophosphamide resulted in a great improvement for the patient. No relapse occurred during one year's follow-up. Although a tumor-mimicking PACNS has no established imaging features, a diagnosis of tumor-mimicking PACNS should be suspected when the MRI reveals inappropriate presentations of a tumor. Greater awareness of this potential manifestation of PACNS may facilitate more prompt diagnosis and treatment.

Mesenchymal stem cells promote tumor angiogenesis via the action of transforming growth factor ß1.

Mesenchymal stem cells (MSCs) may influence the growth and metastasis of various human malignancies, including hepatocellular carcinoma (HCC). Therefore, the underlying mechanisms via which MSCs are able to affect malignancies require investigation. In the present study, the potential role of MSC in the angiogenesis of HCC was investigated. A total of 17 nude mouse models exhibiting human HCC were used to evaluate the effects of MSC on angiogenesis. A total of 8 mice were injected with human MSCs via the tail vein, and the remaining 9 mice were injected with phosphate-buffered saline as a control. A total of 35 days subsequent to the injection of MSCs, the microvessel density (MVD) of tumors was evaluated by immunostaining, using cluster of differentiation 31 antibody. The mRNA levels of transforming growth factor (TGF)ß1, Smad2 and Smad7 were detected using reverse transcription-quantitative polymerase chain reaction. Protein expression levels of TGFß1 and vascular endothelial growth factor (VEGF) in tumor tissues were analyzed using ELISA. Compared with controls, MVD in MSC-treated mice was significantly increased (28.00±9.19 vs. 18.11±3.30; P=0.006). The levels of TGFß1 mRNA in the MSC-treated group were 2.15-fold higher compared with the control group (1.27±0.61 vs. 0.59±0.39; P=0.033), and MVD was higher in the group exhibiting increased TGFß1 mRNA levels compared with the control group (26.50±9.11 vs. 19.44±6.14; P=0.038). In addition, a close correlation between the expression levels of TGFß1 and VEGF was identified. The results of the present study suggested that MSCs may be capable of enhancing the angiogenesis of HCC, which may be partly due to the involvement of TGFß1.