Publications

Ligands of peroxisome proliferator-activated receptor-gamma increase the generation of vascular endothelial growth factor in vascular smooth muscle cells and in macrophages.

Peroxisome proliferator-activated receptors-gamma (PPARgamma) are ligand-inducible transcription factors of the nuclear hormone receptor superfamily. We examined the effect of PPARgamma activation on the generation of vascular endothelial growth factor (VEGF), one of the major angiogenic agents. Rat vascular smooth muscle cells (VSMC) and murine macrophages RAW264.7 were incubated for 24 h with PPARgamma activators: prostaglandin J2 and ciglitazone. PPARgamma were expressed in VSMC and RAW cells and their activity was upregulated in the presence of PGJ2 and ciglitazone. Incubation of the cells with PPARgamma activators significantly augmented the release of VEGF protein into the media, both in resting and in IL-1beta- or LPS-stimulated cultures. The higher protein generation was connected with the increased expression of mRNA and transcriptional activation of VEGF promoter. We conclude that the activation of PPARgamma upregulates the generation of VEGF and may be involved in the regulation of angiogenesis.

Role of NO in angiogenic activities of VEGF isoforms

HIF-1 versus HIF-2 — Is one more important than the other?

Hypoxia-regulated HO-1 expression exerts cytoprotective effects against hypoxic/ischemic injury

Heme Oxygenase and Angiogenic Activity of Endothelial Cells: Stimulation by Carbon Monoxide and Inhibition by Tin Protoporphyrin-IX

The activity of heme oxygenase enzymes (HOs) is responsible for the endogenous source of carbon monoxide (CO). Their activities can be inhibited by tin protoporphyrin-IX (SnPPIX). Recent data indicate the involvement of HOs in the regulation of angiogenesis. Here, we investigated the role of the HO pathway in the production and angiogenic activity of vascular endothelial growth factor (VEGF) in endothelial cells treated with SnPPIX, or cultured in the presence of a CO-releasing molecule (CO-RM). Addition of CO-RM or induction of HO-1 by hemin resulted in a threefold elevation in CO production in culture medium (up to 20.3 microg/L) and was associated with a 30% increase in VEGF synthesis. Much higher levels of CO (up to 60 microg/L) and a further increase in VEGF production (by 277%) were measured in cells treated with prostaglandin-J(2), a potent activator of HO-1. SnPPIX prevented the induction of CO generation and inhibited VEGF synthesis. Moreover, SnPPIX reduced the VEGF-elicited angiogenic activities of endothelial cells by decreasing their proliferation (by 26%), migration (by 46%), formation of tubes on Matrigel (by 48%), and outgrowth of capillaries from endothelial spheroids (by 30%). In contrast, overexpression of HO-1 or incubation of cells with CO-RM led to an increase in capillary sprouting. Thus, HO activity up-regulates VEGF production and augments the capability of endothelial cells to respond to exogenous stimulation.

Mean free path and peak dispersion in the geometration motion in gel electrophoresis

The concept of the mean free path, i.e., the mean distance between subsequent collisions of DNA molecules with gel fibers, is introduced to the model description of the geometration effect. A new formula is derived for the correction to the velocity v of long molecules in gel due to the geometration process: v = v(r)/(1+3s/4b), where v(r) is the velocity without geometration, s is the molecule length and b is the mean free path of molecules. The peak dispersion sigma(x) is evaluated with the same model approach. We get the contribution to the bandwidth from the geometration effect. For b = s the bandwidth is about 2(sx)(1/2), where x is the length of the path of the molecules in gel. The results are compared with experimental data on the linearized plasmid pKecNOS in 4% agarose gel.

The real face of endothelial progenitor cells – Circulating angiogenic cells as endothelial prognostic marker?

MicroRNAs as biomarkers of disease onset

P65Lack of heme oxygenase-1 affects electrophysiological properties of cardiomyocytes derived from human induced pluripotent stem cells

too low to efficiently compensate for the loss of functional myocardium in heart disease.We hypothesize that cardiomyocyte proliferation is tightly controlled by regulatory mechanisms that can be reactivated to promote endogenous repair after heart injuries.Unequivocal identification of cycling cardiomyocytes is a fundamental requirement for the investigation of these mechanisms.Methods: We used a preexisting transgenic mouse model based on the FUCCI (Fluorescent Ubiquitination-based Cell Cycle Indicator) system to discriminate cycling cardiomyocytes (S/G2/M phases, green fluorescent nuclei) from non-cycling ones (G0/G1 phases, red fluorescent nuclei).In mice ubiquitously expressing FUCCI constructs, we used the myocyte-specific perinuclear marker Pericentriolar Material 1 (PCM-1) to distinguish cardiomyocyte from non-myocyte cells in the heart tissue.Single cardiomyocyte isolations from FUCCI mice neonatal hearts followed by FACS sorting into 96-well plates were performed to obtain single cell transcriptome of cycling and non-cycling cardiomyocytes at different post-natal stages.Results: The presented transgenic strategy proved to be efficient for the identification of cycling cardiomyocytes in neonate, juvenile and adult mouse hearts in vitro and in vivo.The validity of transgenes expression was verified in both systems with immunohistochemistry by co-localization of cardiomyocytes and cell cycle markers with FUCCI fluorescence.The FUCCI system allowed us to confirm previous observations of a gradual decrease in the number of cycling cardiomyocyte during the neonatal period.P0 and P7 cardiomyocyte transcriptome were generated using single cell RNA-sequencing.The cell cycle stage of cardiomyocytes as indicated by their FUCCI fluorescence was highly correlated by their transcriptome profile.Conclusion: Strategies that allow to unambiguously identify cycling cardiomyocytes in vitro and in vivo provide important tools to study the regulation of cardiomyocyte proliferation.With the FUCCI system we seek to identify novel molecular targets that could promote cardiomyocyte proliferation, by using transcriptome profiling (RNA-seq) of isolated cycling cardiomyocytes.

PPAR-gamma heterozygosity does not impair EPC mobilization

Supplementary Figure 2 from Hypoxia-Regulated Overexpression of Soluble VEGFR2 Controls Angiogenesis and Inhibits Tumor Growth

<p>PDF - 55KB, Shortening of the minCMV promoter.</p>

Andrzej Szczeklik

Effect of heme and heme oxygenase-1 on vascular endothelial growth factor synthesis and angiogenic potency of human keratinocytes

Opposite effects of prostaglandin-J2 on VEGF in normoxia and hypoxia: role of HIF-1

miR-378a influences vascularization in skeletal muscles

Abstract Aims MicroRNA-378a, highly expressed in skeletal muscles, was demonstrated to affect myoblasts differentiation and to promote tumour angiogenesis. We hypothesized that miR-378a could play a pro-angiogenic role in skeletal muscle and may be involved in regeneration after ischaemic injury in mice. Methods and results Silencing of miR-378a in murine C2C12 myoblasts did not affect differentiation but impaired their secretory angiogenic potential towards endothelial cells. miR-378a knockout (miR-378a−/−) in mice resulted in a decreased number of CD31-positive blood vessels and arterioles in gastrocnemius muscle. In addition, diminished endothelial sprouting from miR-378a−/− aortic rings was shown. Interestingly, although fibroblast growth factor 1 (Fgf1) expression was decreased in miR-378a−/− muscles, this growth factor did not mediate the angiogenic effects exerted by miR-378a. In vivo, miR-378a knockout did not affect the revascularization of the ischaemic muscles in both normo- and hyperglycaemic mice subjected to femoral artery ligation (FAL). No difference in regenerating muscle fibres was detected between miR-378a−/− and miR-378+/+ mice. miR-378a expression temporarily declined in ischaemic skeletal muscles of miR-378+/+ mice already on Day 3 after FAL. At the same time, in the plasma, the level of miR-378a-3p was enhanced. Similar elevation of miR-378a-3p was reported in the plasma of patients with intermittent claudication in comparison to healthy donors. Local adeno-associated viral vectors-based miR-378a overexpression was enough to improve the revascularization of the ischaemic limb of wild-type mice on Day 7 after FAL, what was not reported after systemic delivery of vectors. In addition, the number of infiltrating CD45+ cells and macrophages (CD45+ CD11b+ F4/80+ Ly6G−) was higher in the ischaemic muscles of miR-378a−/− mice, suggesting an anti-inflammatory action of miR-378a. Conclusions Data indicate miR-378a role in the pro-angiogenic effect of myoblasts and vascularization of skeletal muscle. After the ischaemic insult, the anti-angiogenic effect of miR-378a deficiency might be compensated by enhanced inflammation.

Heme Oxygenase-1 Is Required for Angiogenic Function of Bone Marrow-Derived Progenitor Cells: Role in Therapeutic Revascularization

HO-1 is necessary for a proper proangiogenic function of BMDCs. A low level of HO-1 in hyperglycemic mice decreases restoration of perfusion in ischemic muscle, which can be rescued by a local injection of conditioned media from cultured BMDCs.

VEGF–nitric oxide reciprocal regulation

Induced pluripotent stem cells as a model for diabetes investigation

Gene transfer of CuZn superoxide dismutase enhances the synthesis of vascular endothelial growth factor