PEP-1-CAT protects hypoxia/reoxygenation-induced cardiomyocyte apoptosis through multiple sigaling pathways.

Background: Catalase (CAT) breaks down H2O2 into H2O and O2 to protects cells from oxidative damage. However, its translational potential is limited because exogenous CAT cannot enter living cells automatically. This study is aimed to investigate if PEP-1-CAT fusion protein can effectively protect cardiomyocytes from oxidative stress due to hypoxia/reoxygenation (H/R)-induced injury.

PEP-1-CAT-transduced mesenchymal stem cells acquire an enhanced viability and promote ischemia-induced angiogenesis.

Objective: Poor survival of mesenchymal stem cells (MSC) compromised the efficacy of stem cell therapy for ischemic diseases. The aim of this study is to investigate the role of PEP-1-CAT transduction in MSC survival and its effect on ischemia-induced angiogenesis.

Methods: MSC apoptosis was evaluated by DAPI staining and quantified by Annexin V and PI double staining and Flow Cytometry.

[Effect of conditioned medium of mesenchymal stem cells on proliferation, migration and adhesion of human umbilical vein endothelial cells].

The aim of this study was to explore the effect of mesenchymal stem cell (MSC) conditioned medium (MSC-CM) on proliferation, migration and adhesion of human umbilical vein endothelial cell (CRL1730) and its mechanism. Isolation and purification of MSC were performed with the classic adhering method, the surface markers (CD29, CD90, CD45 and CD34) in MSC were detected by flow cytometry. MSC were treated and cultured for 3 d, the MSC-CM or MSC overexpressing stem cell-derived factor-1 (SDF-1) conditioned medium (Ad-SDF-1-MSC-CM) were collected.

VEGF is essential for the growth and migration of human hepatocellular carcinoma cells.

Vascular endothelial growth factor (VEGF) plays a crucial role in tumor angiogenesis. VEGF induces new vessel formation and tumor growth by inducing mitogenesis and chemotaxis of normal endothelial cells and increasing vascular permeability. However, little is known about VEGF function in the proliferation, survival or migration of hepatocellular carcinoma cells (HCC).

[Effect of vascular endothelial growth factor on bone marrow-derived mesenchymal stem cell proliferation and the signaling mechanism].

Objective: To observe the effect of vascular endothelial growth factor (VEGF) on bone marrow-derived mesenchymal stem cell (MSC) proliferation and explore the signaling mechanism involved.

Methods: MSC culture was performed following the classical whole bone marrow adhering method. The characteristics of MSC were identified by induction of multi-lineage differentiation and flow cytometry for surface marker analysis (CD34, CD45, CD29, and CD90).

The combined transduction of copper, zinc-superoxide dismutase and catalase mediated by cell-penetrating peptide, PEP-1, to protect myocardium from ischemia-reperfusion injury.

Background: Our previous studies indicate that either PEP-1-superoxide dismutase 1 (SOD1) or PEP-1-catalase (CAT) fusion proteins protects myocardium from ischemia-reperfusion-induced injury in rats. The aim of this study is to explore whether combined use of PEP-1-SOD1 and PEP-1-CAT enhances their protective effects.

Methods: SOD1, PEP-1-SOD1, CAT or PEP-1-CAT fusion proteins were prepared and purified by genetic engineering.

VEGF/SDF-1 promotes cardiac stem cell mobilization and myocardial repair in the infarcted heart.

Aims: The objective of this study was to investigate whether vascular endothelial growth factor (VEGF) secreted by mesenchymal stem cells (MSC) improves myocardial survival and the engraftment of implanted MSC in infarcted hearts and promotes recruitment of stem cells through paracrine release of myocardial stromal cell-derived factor-1α (SDF-1α).

Methods And Results: VEGF-expressing MSC ((VEGF)MSC)-conditioned medium enhanced SDF-1α expression in heart slices and H9C2 cardiomyoblast cells via VEGF and the vascular endothelial growth factor receptor (VEGFR). The (VEGF)MSC-conditioned medium markedly promoted cardiac stem cell (CSC) migration at least in part via the SDF-1α/CXCR4 pathway and involved binding to VEGFR-1 and VEGFR-3.

[VEGF promotes the proliferation of bone marrow derived mesenchymal stem cells through ERK1/2 signal pathway].

In order to explore the effect of VEGF on mesenchymal stem cell (MSC) proliferation and its possible signal transduction mechanism, MSC culture was performed with the classical bone marrow adhering method; characteristics of passage 3 rat MSC (P3MSC) was identified through multi-differentiation and surface marker assay (CD34, CD45, CD90, CD29); P3MSC were treated with 20 ng/ml VEGF, and the effect of VEGF on the MSC proliferation was measured during 12, 36 and 72 hours by MTT assay. Subsequently, P3MSC were treated with extracellular-signal regulated kinase (ERK1/2) inhibitor PD98059 (50 µmol/L) or p38 mitogen-activated protein kinase (p38MAPK) inhibitor SB203580 (30 µmol/L) for 30 minutes, the culture medium was replaced with new medium including 20 ng/ml VEGF. After 72 hours, the effect of PD98059 or SB203580 on MSC proliferation mediated by VEGF was measured by MTT assay.

[Effect of adenovirus-mediated stromal cell-derived factor-alpha gene transfer on ventricular remodeling in rats with myocardial infarction].

Objective: To explore the effect of adenovirus-mediated human stromal cell-derived factor-1alpha (hSDF-1alpha) on ventricular remodeling in rats with myocardial infarction.

Methods: A recombinant adenoviral plasmid containing hSDF-1alpha cDNA was constructed using homologous recombination in bacteria and the recombinant adenovirus particles expressing hSDF-1alpha (AdV-SDF-1) were prepared. In rat models of myocardial infarction induced by left anterior descending artery occlusion, 1x10(10) PFU AdV-SDF-1 or PFU AdV-LacZ were injected at multiple sites into the infarcted myocardium 1 h after the operation, using 200 l cell-free PBS as the control.

[Protective effect of preconditioning with PEP-1-CAT fusion protein against myocardial ischemia-reperfusion injury in rats].

Objective: To investigate the transduction efficiency of purified PEP-1-CAT fusion protein into rat heart and the protective effect of the fusion protein against myocardial ischemia-reperfusion injury.

Methods: PEP-1-CAT or CAT (500 microg) was injected in SD rats via the caudal vein, using normal saline as the control, and the hearts were harvested at 0.5, 1, 2, 4, 8, and 24 h after the injection.

[The role of PEP-1-SOD1 fusion protein on ischemia-reperfusion injury in isolated perfused rat hearts.].

Objective: The transduction efficiency of the purified PEP-1-SOD1 fusion protein and the effects of PEP-1-SOD1 fusion protein on ischemia reperfusion injury in the isolated perfused rat hearts were investigated.

Methods: The constructed pET15b-SOD1 and pET15b-PEP-1-SOD1 were transformed into BL21 (DE3) for expression and purification of SOD1 and PEP-1-SOD1, respectively. Isolated perfused rat hearts were subjected to 60 min of global ischemia and 30 min of reperfusion and treated with vehicle, 100 micromol/L SOD1 and 25, 50, 100 micromol/L PEP-1-SOD1, respectively.

Effect of p27mt gene on apoptosis of the colorectal cancer cell line Lovo.

Aim: To construct p27mt recombinant adenovirus, transfect the colorectal cell line Lovo and observe the effects of p27mt on Lovo cell apoptosis and cell cycle inhibition.

Methods: We constructed recombinant adenovirus containing p27mt by homologous recombination in bacteria. The colorectal cancer cell line Lovo was infected with recombinant replication-defective adenovirus Ad-p27mt, and expression of p27mt was determined by Western blotting; the inhibitory effect of p27mt on Lovo cells was detected by cytometry.

[Comparison of migration characteristics of MSCs in different assay systems].

The aim of this study was to explore the difference of MSC migration mediated by SDF-1/CXCR4 axis through Boyden chamber in vitro migration assay. The SDF-1 density-dependence of MSC migration was observed. Subsequently, the effects of different blocking agents on hSDF-MSC migration were observed after MSC were treated with 50 nmol/L wortmannin, 10 micromol/L LY294002, 50 micromol/L PD98059, 10 micromol/L U73122, 126 micromol/L AMD3100 and 50 nmol/L verapamil respectively.

In vivo protein transduction: delivery of PEP-1-SOD1 fusion protein into myocardium efficiently protects against ischemic insult.

Myocardial ischemia-reperfusion injury is a medical problem occurring as damage to the myocardium following blood flow restoration after a critical period of coronary occlusion. Oxygen free radicals (OFR) are implicated in reperfusion injury after myocardial ischemia. The antioxidant enzyme, Cu, Zn-superoxide dismutase (Cu, Zn-SOD, also called SOD1) is one of the major means by which cells counteract the deleterious effects of OFR after ischemia.

[Adenovirus-mediated stromal cell-derived factor-1 alpha gene transfer promotes mesenchymal stem cell migration].

Objective: To explore the role of stromal-derived factor-1 (SDF-1) in the migration of mesenchymal stem cells (MSCs) and the underlying signal transduction mechanism.

Methods: Rat bone marrow-derived MSCs were infected with 100 ml recombinant adenovirus containing human SDF-1alpha gene (Ad-hSDF-1alpha), and the cell migration changes were observed at 1, 2, and 3 days after the infection. Twelve hours after Ad-hSDF-1alpha transfection, the MSCs in separate cultures were treated with wortmannin (50 nmol/L), LY294002 (10 mmol/L), PD98059 (50 mmol/L), U73122 (10 mmol/L), AMD3100 (0.

[The protective effect of PEP-1-SOD1 preconditioning on hypoxia/reoxygenation injury in cultured human umbilical vein endothelial cells].

Objective: To construct prokaryotic expression vector of pET15b-PEP-1-SOD1 and investigate whether PEP-1-SOD1 fusion protein could be transduced into human umbilical vein endothelial cells (HUVECs) and the effects on hypoxia/reoxygenation injury.

Methods: The recombinant plasmids pET15b-SOD1 and pET15b-PEP-1-SOD1 were constructed and transformed into E. coli BL21 (DE3) to express SOD1 and PEP-1-SOD1 with an N-terminal His-tag.

[Cell-penetrating peptide PEP-1-mediated transduction of enhanced green fluorescent protein into human umbilical vein endothelial cells].

Objective: To investigate the penetrating ability of fusion protein PEP-1-EGFP with human umbilical vein endothelial cells.

Methods: Two prokaryotic expression plasmids pET15b-EGFP and pET15b-PEP-1-EGFP were constructed and transformed into E. coli BL21 (DE3) to express EGFP and fusion protein PEP-1-EGFP, respectively.

[Cell-penetrating peptide PEP-1-mediated transduction of enhanced green fluorescent protein into human colorectal cancer SW480 cells].

Background & Objective: Cell-penetrating peptides, a class of small cationic peptides, could mediate macromolecules transduction into many cell lines. This study was to explore the penetrating ability of PEP-1 in the transduction of enhanced green fluorescent protein (EGFP) into human colorectal cancer cell line SW480.

Methods: Two prokaryotic expression plasmids pET15b-EGFP and pET15b-PEP-1-EGFP were constructed and transformed into E.

[The protective effect of PEP-1-CAT fusion protein on hydrogen peroxide-induced oxidative stress injury in human umbilical vein endothelial cells].

Objective: To investigate the transduction ability of PEP-1-CAT fusion protein into human umbilical vein endothelial cell (HUVECs) and the effects on hydrogen-peroxide (H2O2)-induced oxidative stress injury in these cells.

Methods: With the use of TA-cloning program and isocaudamer technique, the pET15b-PEP-1-CAT of prokaryotic expression plasmid was successfully constructed. The recombinant plasmid was transformed into E.

[Construction of prokaryotic expression plasmid pET15b-PEP-1-CAT and expression and purification of PEP-1-CAT fusion protein].

Objective: To construct the prokaryotic expression plasmid pET15b-PEP-1-CAT to obtain purified fusion protein of PEP-1-CAT.

Methods: Using pfu DNA polymerase, the full-length human catalase cDNA was amplified by PCR from pZeoSV2(+)-CAT plasmid, and the PCR product was added with "A" using Taq DNA polymerase. The purified product of CAT cDNA with the base A at its 3' end was ligated with pGEM-T Easy vector and transformed into DH5alpha.

[Expression and purification of PEP-1-EGFP fusion protein and its transduction into human umbilical vein endothelial cells].

Objective: To construct the expression vector pET15b-pep-1-EGFP and purify the fusion protein PEP-1-EGFP expressed in E. coli BL21(DE(3)) for evaluating the cell-penetrating capability of the cell-penetrating peptide PEP-1.

Methods: Two oligonucleotides encoding PEP-1 was synthesized and annealed to generate PEP-1-encoding DNA.