Metformin regulates differentiation of bone marrow-derived endothelial progenitor cells via multiple mechanisms.

OBJECTIVE: The aim of this study was to investigate the effect of metformin on endothelial progenitor cells (EPCs) differentiation and the possible mechanisms. METHODS: EPCs were treated with metformin and differentiation, migration and tube formation of EPCs were evaluated. Moreover, we also assessed the AMPK-mTOR-p70S6K pathway, AMPK related autophagy pathway and eNOS-NO pathway to explore the mechanisms. RESULTS: Metformin treatment could significantly increase differentiation of EPCs. On the mechanisms, increased level of AMPKand eNOS phosphorylation, LC3 expression and NO production, and decreased mTOR, p70 S6K as well as TGF-ß expression were found in EPCs. The AMPK inhibitor compound C, Atg5 knocking-down and eNOS inhibitor l-NAME could reverse the effect exerted by metformin. CONCLUSIONS: Our results here showed that metformin could regulate the differentiation of EPCs. Autophagy related pathway and AMPK-eNOS-NO pathway were involved in the mechanisms.

METTL5 promotes cell proliferation, invasion, and migration by up-regulating Toll-like receptor 8 expression in colorectal cancer.

BACKGROUND: N6-methyladenosine (m6A) modification represents the predominant alteration found in eukaryotic messenger RNA and plays a crucial role in the progression of various tumors. However, despite its significance, the comprehensive investigation of METTL5, a key m6A methyltransferase, in colorectal cancer (CRC) remains limited. AIM: To investigate the role of METTL5 in CRC. METHODS: We assessed METTL5 expression levels in clinical samples obtained from CRC patients as well as in CRC cell lines. To elucidate the downstream targets of METTL5, we performed RNA-sequencing analysis coupled with correlation analysis, leading us to identify Toll-like receptor 8 (TLR8) as a potential downstream target. In vitro functional assessments of METTL5 and TLR8 were conducted using CCK-8 assays, scratch assays, as well as assays measuring cell migration and invasion. RESULTS: Our findings reveal a pronounced upregulation of METTL5 expression in both CRC cells and tissues, which correlated significantly with an unfavorable prognosis. In vitro experiments unequivocally demonstrated the oncogenic role of METTL5, as evidenced by its promotion of CRC cell proliferation, invasion, and migration. Notably, we identified TLR8 as a downstream target of METTL5, and subsequent down-regulation of TLR8 led to a significant inhibition of CRC cell proliferation, invasion, and tumor growth. CONCLUSION: The heightened expression of METTL5 in CRC is strongly associated with clinicopathological features and a poor prognosis, thereby underscoring its potential utility as a critical marker for facilitating early diagnosis and prognostication in CRC.

[Influence of glucagon-like peptide-2 on intestinal lymphocyte homing in mice with acute pancreatitis].

OBJECTIVE: To investigate the influence of glucagon-like peptide-2 (GLP-2) on intestinal lymphocyte homing receptor-integrin alpha 4 beta 7 and homing ligand-intestinal mucosal addressin cell adhesion molecule-1 (MAdCAM-1) in mice with acute pancreatitis (AP). METHODS: A total of 96 mice were divided into three groups randomly (n=32 in each group): AP group, GLP-2 group and control group. Murine AP model was reproduced by intraperitoneal injection of caerulein and lipopolysaccharides (LPS). GLP-2 (250 microg/kg) was injected intraperitoneally at 15 minutes after the establishment of model, then it was injected twice a day for 3 days in GLP-2 group, while the mice in control group received normal saline instead. Mice were sacrificed at 6, 12, 24 and 48 hours after reproduction of AP, and tissue specimens were harvested. Integrin alpha 4 beta 7 positive peripheral blood lymphocytes were determined by flow cytometry. The expression of MAdCAM-1 in the terminal ileum mucosa and Peyer patch was measured by immunohistochemistry. Same observations were also done in the control and GLP-2 groups. RESULTS: Compared with control group, integrin alpha 4 beta 7 positive lymphocyte in peripheral blood and the expression of MAdCAM-1 in the terminal ileum mucosa and Peyer patch were significantly reduced at 6, 12, 24 and 48 hours in AP mice (all P<0.05). Integrin alpha 4 beta 7 positive lymphocyte and the expression of MAdCAM-1 were markedly higher in GLP-2 group than those in AP group (all P<0.05), but were lower in GLP-2 group than those in control group (all P>0.05). CONCLUSION: Administration of GLP-2 may restore expression of integrin alpha 4 beta 7 and MAdCAM-1, promote lymphocyte homing to intestine, thus improve the immunological function of intestine.

Safety and Efficacy of Low Dosage of Urokinase for Catheter-directed Thrombolysis of Deep Venous Thrombosis.

BACKGROUND: Catheter-directed thrombolysis (CDT) has been a mainstay in treating deep venous thrombosis (DVT). However, the optimal dosage of a thrombolytic agent is still controversial. The goal of this study was to evaluate the safety and efficacy of low dosage urokinase with CDT for DVT. METHODS: A retrospective analysis was performed using data from a total of 427 patients with DVT treated with CDT in our single center between July 2009 and December 2012. Early efficacy of thrombolysis was assessed with a thrombus score based on daily venography. The therapeutic safety was evaluated by adverse events. A venography or duplex ultrasound was performed to assess the outcome at 6 months, 1 year and 2 years postoperatively. RESULTS: The mean total dose of 3.34 (standard deviation [SD] 1.38) million units of urokinase was administered during a mean of 5.18 (SD 2.28) days. Prior to discharge, Grade III (complete lysis) was achieved in 154 (36%) patients; Grade II (50-99% lysis) in 222 (52%); and Grade I (50% lysis) in 51 (12%). The major complications included one intracranial hemorrhage, one hematochezia, five gross hematuria, and one pulmonary embolism. Moreover, no death occurred in the study. CONCLUSIONS: Treatment of low-dose catheter-directed thrombosis is an efficacious and safe therapeutic approach in patients with DVT offering good long-term outcomes and minimal complications.

Autophagy protein 5 enhances the function of rat EPCs and promotes EPCs homing and thrombus recanalization via activating AKT.

Deep venous thrombosis (DVT) is one of the most common peripheral vascular diseases. The roles of bone marrow-derived endothelial progenitor cells (EPCs) on the recanalization of venous thrombosis has been suggested recently, while the underlying mechanisms are not completely understood. Our objective was to investigate the functions of autophagy protein 5 (ATG5) in rat EPCs and its potential application in DVT. We have found that silencing of ATG5 or pharmacological suppression of ATG5 in rat EPCs reduces both the migration and psudotube formation under hypoxia in vitro. In line, overexpression of ATG5 significantly enhances the EPCs migration and psudotube formation capabilities. More importantly, injection of EPCs that stably express ATG5 increases EPC homing to the ischemic site and promotes thrombus recanalization in a rat DVT model in vivo. Mechanistically, we have shown that ATG5 overexpression enhances psudotube formation via the activation of AKT. These findings suggest that ATG5-AKT signaling plays an essential role in EPC migration and psudotube formation. Regulation of ATG5-AKT signaling may provide a potential novel therapy for DVT.