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1
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Carbon monoxide - a "new" gaseous modulator of gene expression.

100%
Dulak J., Józkowicz A.
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2003
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vol. 50
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issue 1
31-47
EN
Carbon monoxide (CO) is an odorless, tasteless and colorless gas which is generated by heme oxygenase enzymes (HOs). HOs degrade heme releasing equimolar amounts of CO, iron and biliverdin, which is subsequently reduced to bilirubin. CO shares many properties with nitric oxide (NO), an established cellular messenger. Both CO and NO are involved in neural transmission and modulation of blood vessel function, including their relaxation and inhibition of platelet aggregation. CO, like NO, binds to heme proteins, although CO binds only ferrous (FeII) heme, whereas NO binds both ferrous and ferric (FeIII). CO enhances the activity of guanylate cyclase although it is less potent than NO. In contrast, CO inhibits other heme proteins, such as catalase or cytochrome P450. The effects of CO on gene expression can be thus varied, depending on the cellular microenvironment and the metabolic pathway being influenced. In this review the regulation of gene expression by HO/CO in the cardiovascular system is discussed. Recent data, derived also from our studies, indicate that HO/CO are significant modulators of inflammatory reactions, influencing the underlying processes such as cell proliferation and production of cytokines and growth factors.
2
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Effects of protoporphyrins on production of nitric oxide and expression of vascular endothelial growth factor in vascular smooth muscle cells and macrophages.

100%
Józkowicz A., Dulak J.
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2003
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vol. 50
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issue 1
69-79
EN
Heme oxygenase-1 (HO-1), an inducible enzyme degrading heme to biliverdin, iron and carbon monoxide, is involved in regulation of inflammation and angiogenesis. Tin protoporphyrin (SnPPIX) and zinc protoporphyrin (ZnPPIX) are commonly used as competitive inhibitors of HO-1. We aimed to compare the effects of SnPPIX and ZnPPIX on the production of vascular endothelial growth factor (VEGF), activity of inducible nitric oxide synthase (iNOS) and cell viability. All experiments were performed on rat vascular smooth muscle cells and murine RAW264.7 macrophages treated with 3-10 μM protoporphyrins. Some cells were additionally stimulated with IL-1β or with lipopolysaccharide. After a 24 h incubation period SnPPIX and ZnPPIX significantly reduced the generation of VEGF in vascular smooth muscle cells and RAW264.7, both in resting and stimulated cells. The inhibitory potentials of both protoporphyrins on VEGF synthesis were very similar. In contrast, analysis of iNOS activity revealed that results obtained with different HO-1 inhibitors are discrepant. Generation of nitric oxide by iNOS was significantly increased by SnPPIX but strongly decreased by ZnPPIX. Similar differences were observed when cell viability was compared. SnPPIX improved the cell survival rate, whereas the same doses of ZnPPIX exerted some cytotoxic effects. In summary, SnPPIX and ZnPPIX can be used as HO-1 inhibitors in some experimental models. However, these compounds produce also HO-independent effects, which can make the interpretation of experiments very uncertain. Thus the involvement of the HO-1 pathway should be always confirmed by more specific methods.
3
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Helper-dependent adenoviral vectors in experimental gene therapy

100%
Józkowicz A., Dulak J.
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2005
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vol. 52
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issue 3
589-599
EN
In the majority of potential applications gene therapy will require an effective transfer of a transgene in vivo resulting in high-level and long-term transgene expression, all in the absence of significant toxicity or inflammatory responses. The most efficient vehicles for delivery of foreign genes to the target tissues are modified adenoviruses. Adenoviral vectors of the first generation, despite the high infection efficacy, have an essential drawback: they induce strong immune response, which leads to short term expression of the transgene, and limits their usefulness in clinical trials. In contrast, helper-dependent adenoviral vectors (HdAd) lacking all viral coding sequences display only minimal immunogenicity and negligible side-effects, allowing for long-term transgene expression. Thus, HdAd vehicles have become the carrier of choice for adenoviral vector-mediated experimental gene therapy, effectively used in animal models for delivery of transgenes into the liver, skeletal muscle, myocardium or brain. Strong and long-lasting expression of therapeutic genes has allowed for successful treatment of dyslipidemias, muscular dystrophy, obesity, hemophilia, and diabetes. Additionally, the large cloning capacity of HdAd, up to 37 kb, facilitates the use of physiologically regulated, endogenous promoters, instead of artificial viral promoter sequences. This enables also generation of the single vectors expressing multiple genes, which can be potentially useful for treatment of polygenic diseases. In this review we characterize the basic features of HdAd vectors and describe some of their experimental and potential clinical applications.
4
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Adult stem cells: hopes and hypes of regenerative medicine

71%
Dulak J., Szade K., Szade A., Nowak W., Józkowicz A.
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2015
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vol. 62
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issue 3
329-337
EN
Stem cells are self-renewing cells that can differentiate into specialized cell type(s). Pluripotent stem cells, i.e. embryonic stem cells (ESC) or induced pluripotent stem cells (iPSC) differentiate into cells of all three embryonic lineages. Multipotent stem cells, like hematopoietic stem cells (HSC), can develop into multiple specialized cells in a specific tissue. Unipotent cells differentiate only into one cell type, like e.g. satellite cells of skeletal muscle. There are many examples of successful clinical applications of stem cells. Over million patients worldwide have benefited from bone marrow transplantations performed for treatment of leukemias, anemias or immunodeficiencies. Skin stem cells are used to heal severe burns, while limbal stem cells can regenerate the damaged cornea. Pluripotent stem cells, especially the patient-specific iPSC, have a tremendous therapeutic potential, but their clinical application will require overcoming numerous drawbacks. Therefore, the use of adult stem cells, which are multipotent or unipotent, can be at present a more achievable strategy. Noteworthy, some studies ascribed particular adult stem cells as pluripotent. However, despite efforts, the postulated pluripotency of such events like "spore-like cells", "very small embryonic-like stem cells" or "multipotent adult progenitor cells" have not been confirmed in stringent independent studies. Also plasticity of the bone marrow-derived cells which were suggested to differentiate e.g. into cardiomyocytes, has not been positively verified, and their therapeutic effect, if observed, results rather from the paracrine activity. Here we discuss the examples of recent studies on adult stem cells in the light of current understanding of stem cell biology.
5
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Nitric oxide mediates the mitogenic effects of insulin and vascular endothelial growth factor but not of leptin in endothelial cells

61%
Józkowicz A., Pankiewicz J., Dulak J., Partyka Ł., Wybrańska I., Huk I., Dembińska-Kieć A.
Acta Biochimica Polonica
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1999
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vol. 46
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issue 3
703-715
6
Content available remote

Prostaglandin-J2 upregulates expression of matrix metalloproteinase-1 independently of activation of peroxisome proliferator-activated receptor-γ.

61%
Józkowicz A., Huk I., Nigisch A., Cisowski J., Weigel G., Dulak J.
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2003
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vol. 50
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issue 3
677-689
EN
Peroxisome proliferator-activated receptor-γ (PPARγ) is a ligand-inducible nuclear receptor that functions as a transcription factor involved in lipid metabolism, inflammatory response and angiogenesis. The most potent endogenous PPARγ activator is 15-deoxy-Δ12,14prostaglandin-J2 (15d-PGJ2), whereas synthetic ligands include the oral antidiabetic drugs thiazolidinediones (TZDs). Activation of PPARγ was reported to decrease the synthesis of matrix metalloproteinases (MMPs) in vascular smooth muscle cells and macrophages. We aimed to investigate the effect of PPARγ ligands on expression of MMP-1 and urokinase plasminogen activator (uPA) in human microvascular endothelial cells (HMEC-1). We found that treatment of HMEC-1 with 15d-PGJ2 increased the synthesis of MMP-1 protein up to 168% comparing to untreated cells. TZDs (ciglitazone and troglitazone), more potent activators of PPARγ in HMEC-1, did not influence MMP-1 production, arguing against the involvement of PPARγ in this process. Importantly, the stimulatory effect of 15d-PGJ2 was reversed by the antioxidant N-acetyl-cysteine (NAC), suggesting a contribution of oxidative stress. We demonstrated also that 15d-PGJ2 did not change the activity of MMP-1 promoter, but increased the stability of MMP-1 mRNA. In contrast, 15d-PGJ2 very potently inhibited the synthesis of uPA. This effect was in part mimicked by ciglitazone and troglitazone implying an involvement of PPARγ. Accordingly, NAC did not modify the inhibitory effect of 15d-PGJ2 on uPA expression. In conclusion, we postulate that 15d-PGJ2 may differently regulate the synthesis of proteases involved in angiogenesis : it upregulates MMP-1 expression in HMEC-1 through induction of oxidative stress, and inhibits uPA synthesis partly by activation of PPARγ.
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