Angiogenesis requires the mobilization of progenitor cells from the bone marrow and homing of progenitor cells to ischemic tissue. Statins facilitate the former, and the chemokine stromal cell-derived factor-1 (SDF-1) enhances the latter. Their combined influence on angiogenesis was studied in vivo in the ischemic hindlimb C57BL/6 mouse model. The ischemic to non-ischemic perfusion ratio increased from 0.29 ؎ 0.02 immediately after femoral excision to 0.51 ؎ 0.10 three weeks after the surgery in the mice treated with either fluvastatin or SDF-1 alone, which is significantly better than the control (0.38 ؎ 0.05, p < .05, n ‫؍‬ 6). The combined use of fluvastatin and SDF-1 further improved the reperfusion ratio (0.62 ؎ 0.08, p < .05). More cell proliferation, less apoptosis, enhanced bone marrow-derived endothelial progenitor cell (EPC) incorporation and higher capillary density were observed in ischemic tissue treated with both statin and SDF-1. In vitro monotreatment with either fluvastatin (100 nM) or SDF-1 (100 ng/ ml) facilitated EPC proliferation and migration, inhibited EPC apoptosis, enhanced expression of matrix metalloproteinase-2 (MMP-2) and -9 (MMP-9), and increased Akt phosphorylation and nitric oxide production. These effects were significantly augmented by the two agents together and ablated by inhibitors of either Akt or nitric oxide synthase (NOS). In conclusion, statin and SDF-1 additively enhance progenitor cell migration and proliferation and down-regulate EPC apoptosis, resulting in improved reperfusion via activation of the Akt/NOS pathway and up-regulation of MMP-2 and MMP-9 expression.

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BackgroundGastric cancer is one of the most common malignant tumors. Cyclin G2 has been shown to be associated with the development of multiple types of tumors, but its underlying mechanisms in gastric tumors is not well-understood. The aim of this study is to investigate the role and the underlying mechanisms of cyclin G2 on Wnt/β-catenin signaling in gastric cancer.MethodsReal-time PCR, immunohistochemistry and in silico assay were used to determine the expression of cyclin G2 in gastric cancer. TCGA datasets were used to evaluate the association between cyclin G2 expression and the prognostic landscape of gastric cancers. The effects of ectopic and endogenous cyclin G2 on the proliferation and migration of gastric cancer cells were assessed using the MTS assay, colony formation assay, cell cycle assay, wound healing assay and transwell assay. Moreover, a xenograft model and a metastasis model of nude mice was used to determine the influence of cyclin G2 on gastric tumor growth and migration in vivo. The effects of cyclin G2 expression on Wnt/β-catenin signaling were explored using a TOPFlash luciferase reporter assay, and the molecular mechanisms involved were investigated using immunoblots assay, yeast two-hybrid screening, immunoprecipitation and Duolink in situ PLA. Ccng2−/− mice were generated to further confirm the inhibitory effect of cyclin G2 on Wnt/β-catenin signaling in vivo. Furthermore, GSK-3β inhibitors were utilized to explore the role of Wnt/β-catenin signaling in the suppression effect of cyclin G2 on gastric cancer cell proliferation and migration.ResultsWe found that cyclin G2 levels were decreased in gastric cancer tissues and were associated with tumor size, migration and poor differentiation status. Moreover, overexpression of cyclin G2 attenuated tumor growth and metastasis both in vitro and in vivo. Dpr1 was identified as a cyclin G2-interacting protein which was required for the cyclin G2-mediated inhibition of β-catenin expression. Mechanically, cyclin G2 impacted the activity of CKI to phosphorylate Dpr1, which has been proved to be a protein that acts as a suppressor of Wnt/β-catenin signaling when unphosphorylated. Furthermore, GSK-3β inhibitors abolished the cyclin G2-induced suppression of cell proliferation and migration.ConclusionsThis study demonstrates that cyclin G2 suppresses Wnt/β-catenin signaling and inhibits gastric cancer cell growth and migration through Dapper1.Electronic supplementary materialThe online version of this article (10.1186/s13046-018-0973-2) contains supplementary material, which is available to authorized users.

Background and Purpose-Zinc has been reported to possess both neurotoxic and neuroprotective capabilities. The effects of elevated intracellular zinc accumulation following transient focal cerebral ischemia remain to be fully elucidated. Here, we investigated whether removing zinc with the membrane-permeable zinc chelator, N,N,Nʹ,Nʹ-tetrakis(2-pyridylmethyl) ethylenediamine (TPEN), would decrease the intracellular levels of zinc in the ischemic tissue, leading to reduced brain damage and improved neurological outcomes. Methods-Rats were pretreated with TPEN or vehicle before or after a 90-minute middle cerebral artery occlusion. Cerebral infarct volume, neurological functions, neuronal apoptosis, poly(ADP-ribose) polymerase activity, and cytosolic labile zinc were assessed after ischemia and reperfusion. Results-Cerebral ischemia caused a dramatic cytosolic labile zinc accumulation in the ischemic tissue, which was decreased markedly by TPEN (15 mg/kg) pretreatment. Chelating zinc lead to reduced infarct volume compared with vehicle-treated middle cerebral artery occlusion rats, accompanied by much improved neurological assessment and motor function, which were sustained for 14 days after reperfusion. We also determined that reducing zinc accumulation rescued neurons from ischemia-induced apoptotic death by reducing poly(ADP-ribose) polymerase-1 activation. Conclusions-Ischemia-induced high accumulation of intracellular zinc significantly contributed to ischemic brain damage through promotion of neuronal apoptotic death. Removing zinc may be an effective and novel approach to reduce ischemic brain injury. (Stroke. 2014;45:1139-1147.)