Targeted depletion of monocyte/macrophage suppresses aortic dissection with the spatial regulation of MMP-9 in the aorta.

AIM: Aortic dissection (AD) is a devastating disease with rapid progression and high mortality, while the initiation mechanism of AD is far from clear. MAIN METHODS: AD was established by feeding mice with ß-aminopropionitrile in the diet and usage of angiotensin II (AngII) to trigger the rupture of aorta. LysMiDTR mice were constructed by crossing of LysM-Cre mice with ROSA26iDTR mice and characterized by diphtheria toxin receptor (DTR) expression in monocytes/macrophages specifically. Then, monocyte/macrophage depletion in LysMiDTR mice was conducted to evaluate the function of monocyte/macrophage in AD. Finally, the underlying mechanism was elucidated by proteomics, Western blot analysis, immunofluorescence staining and bioinformatics analysis. KEY FINDINGS: First, we detected T lymphocytes, macrophages and neutrophils infiltrated into the aorta simultaneously when AD occurred, and macrophages were the most abundant cell type. Then, targeted depletion of monocyte/macrophage in LysMiDTR mice considerably inhibited the occurrence of AD and infiltration of T lymphocytes and neutrophils. Furthermore, monocyte transfusion into LysMiDTR mice augmented the rupture of aorta, jointly supporting the key roles of monocytes/macrophages in AD development. Mechanistically, a total of 347 proteins exhibited significant differences in intensity after monocyte/macrophage depletion according to quantitative mass spectrometry. Specifically, increased matrix metalloprotein-9 (MMP-9) level in AD may be of concern due to its functions in vascular remodeling. The infiltration of macrophages considerably up-regulated MMP-9, and MMP-9 co-localized with macrophages at the tearing area of aorta. SIGNIFICANCE: Macrophages infiltrated into the tear sites of the aortic wall, regulated extracellular remodeling pathway, functioned as initiators to switch on the occurrence of AD.

Plasma Amino Acid Profile in Patients with Aortic Dissection.

Aortic dissection (AD), a severe cardiovascular disease with the characteristics of high mortality, is lack of specific clinical biomarkers. In order to facilitate the diagnosis of AD, we investigated plasma amino acid profile through metabolomics approach. Total 33 human subjects were enrolled in the study: 11 coronary heart disease (CHD) patients without aortic lesion and 11 acute AD and 11 chronic AD. Amino acids were identified in plasma using liquid chromatography and mass spectrometry (LC-MS/MS), and were further subjected to multiple logistic regression analysis. The score plots of principal component analysis (PCA) and partial least squares-discriminate analysis (PLS-DA) showed clear discrimination of CHD patients with AD, acute AD or chronic AD patients, respectively. The contents of histidine, glycine, serine, citrate, ornithine, hydroxyproline, proline and sarcosine were significant different in acute AD patients comparing with CHD patients. The levels of citrate, GABA, glutamate and cysteine were significant different in chronic AD patients comparing with CHD patients. The contents of glutamate and phenylalanine were significant changed in acute AD patients comparing with chronic AD patients. Plasma aminograms were significantly altered in patients with AD comparing with CHD, especially in acute AD, suggesting amino acid profile is expected to exploit a novel, non-invasive, objective diagnosis for AD.

Amelioration of salvianolic acid C on aortic structure in apolipoprotein E-deficient mice treated with angiotension II.

AIMS: Aortic aneurysm is a disastrous vascular disease with high morbidity and mortality. Matrix metalloproteinases (MMPs), especially MMP-9, is implicated in the development of aortic aneurysm, but the effective MMP inhibitors are far from development. To develop new candidate compound for aortic aneurysm therapy, we evaluated the effects of salvianolic acid C (SalC) against the formation of aortic aneurysm. MATERIALS AND METHODS: Aortic aneurysm was induced by implantation of angiotension II (AngII) minipump in apolipoprotein E-deficient (ApoE-/-) mice. MMPs activity was evaluated by enzyme kinetic analysis in vitro and in-gel gelatin zymography in vivo. The formation of aortic aneurysm was confirmed based on aortic maximum diameter. Hematoxylin and eosin stain was used to evaluate aortic structure, picrosirius red stain was for collagen deposition, and orcein stain was for elastin fragmentation. Macrophage infiltration was detected by CD68 immunohistochemistry. KEY FINDINGS: Firstly, SalC showed significant inhibition on the activity of MMP-2 and MMP-9. Aortic aneurysm was defined as >50% increase in maximum diameter of aorta, and the down-regulated tendency of 20mg/kg SalC against formation of aortic aneurysm was detected. Also, 22.2% rupture was detected in ApoE-/- mice, while no rupture of aortic aneurysm was found with 20mg/kg SalC treatment. Then, SalC was detected to maintain the integrity of aortic structure and protect elastin against fragmentation. Finally, SalC considerably inhibited infiltration of macrophage in the injury site of aorta. SIGNIFICANCE: SalC significantly ameliorated the progression of aortic aneurysm in ApoE-/- mice, and held great potential for aortic aneurysm therapy.

Downregulation of TRAP1 sensitizes glioblastoma cells to temozolomide chemotherapy through regulating metabolic reprogramming.

Cancer cells preferentially use aerobic glycolysis to support growth, a metabolic alteration commonly referred to as the 'Warburg effect.' Here, we show that the tumor necrosis factor receptor-associated protein 1 (TRAP1) is crucial for the Warburg effect in human glioblastoma multiforme (GBM). In contrast to normal brain, GBMs show increased TRAP1 expression. We used both GBM cell lines and neurospheres derived from human GBM specimens to examine the effects of Knockdown of TRAP1 on GBM cell lines and glioma stem cells. We also used a neurosphere recovery assay that measured neurosphere formation at three time points to assess the capacity of the culture to repopulate after knockdown of TRAP1. Our results showed that knockdown of TRAP1 strongly decreased GBM cell proliferation and migration, inhibited neurosphere recovery, secondary neurosphere formation, and enhanced the therapeutic effect of temozolomide in neurosphere cultures. In GBM, knockdown of TRAP1 appeared to inhibit tumor growth and migration through its regulatory effects on metabolic reprogramming.

Combined Salvianolic Acid B and Ginsenoside Rg1 Exerts Cardioprotection against Ischemia/Reperfusion Injury in Rats.

Lack of pharmacological strategies in clinics restricts the patient prognosis with myocardial ischemia/reperfusion (I/R) injury. The aim of this study was to evaluate the cardioprotection of combined salvianolic acid B (SalB) and ginsenoside Rg1 (Rg1) against myocardial I/R injury and further investigate the underlying mechanism. I/R injury was induced by coronary artery ligation for Wistar male rats and hypoxia/reoxygenation injury was induced on H9c2 cells. Firstly, the best ratio between SalB and Rg1was set as 2:5 based on their effects on heart function detected by hemodynamic measurement. Then SalB-Rg1 (2:5) was found to maintain mitochondrial membrane potential and resist apoptosis and necrosis in H9c2 cell with hypoxia/reoxygenation injury. Companying with same dose of SalB or Rg1 only, SalB-Rg1 showed more significant effects on down-regulation of myocardial infarct size, maintenance of myocardium structure, improvement on cardiac function, decrease of cytokine secretion including TNF-α, IL-1ß, RANTES and sVCAM-1. Finally, the SalB-Rg1 improved the viability of cardiac myocytes other than cardiac fibroblasts in rats with I/R injury using flow cytometry. Our results revealed that SalB-Rg1 was a promising strategy to prevent myocardial I/R injury.

Impact of autophagy inhibition at different stages on cytotoxic effect of autophagy inducer in glioblastoma cells.

BACKGROUND/AIMS: Glioblastoma multiforme (GBM) is the most malignant primary brain tumor with a poor prognosis. Combination treatment of autophagy inducer and autophagy inhibitor may be a feasible solution to improve the therapeutic effects. However, the correlation between them is unclear. The purpose of this study was to investigate the effect of autophagy inhibition at different stages on cytotoxicity of autophagy inducers in glioblastoma cells. METHODS: Autophagy inhibition at early stage was achieved by 3-methyladenine (3-MA) or Beclin 1 shRNA. Autophagy inhibition at late stage was achieved by chloroquine (CQ) or Rab7 shRNA. Cell viability was assessed by MTT assay. Autophagy was measured using transmission electron microscopy and western blot. Apoptosis was measured using western blot and flow-cytometry. RESULTS: Inhibition of early steps of autophagy by 3-MA or Beclin 1 knockdown decreased the toxic effect of arsenic trioxide (ATO) in GBM cell lines. In contrast, blockade of autophagy flux at late stage by CQ or Rab7 knockdown enhanced the cytotoxicity of ATO, and caused accumulation of degradative autophagic vacuoles and robust apoptosis. Moreover, depletion of Beclin 1 abolished the synergistic effect of ATO and CQ by reducing autophagy and apoptosis. Combination of CQ with other autophagy inducers also induced synergistic apoptotic cell death. CONCLUSION: These results suggest that inhibition of late process of autophagy, not initial step, increases the cytotoxic effect of autophagy inducers via autophagy and apoptosis, which may contribute to GBM chemotherapy.