Piotr Skopiński

Potential role of metalloproteinase inhibitors from radiation‑sterilized amnion dressings in the healing of venous leg ulcers

Chronic wounds are a significant socio-economic problem, thus, the improvement of the effectiveness of their treatment is an important objective for public health strategies. The predominant stage of the chronic wound is the inflammatory reaction which is associated with the damage of tissues, possibly due to the excessive secretion and activation of matrix metalloproteinases (MMPs). Several reports have suggested that amnion dressing inhibits tissue destruction and accelerates wound healing. Our recent study revealed that sterilized amnion stimulates keratinocyte proliferation in vitro, while the present study focused on the clinical application of radiation-sterilized amnion in chronic venous leg ulcers and aimed to explain the possible mechanism of its in vivo action. The study involved 25 individuals suffering from venous leg ulceration with a surface area of 10-100 cm2 and a healing rate below 10% per week, as verified during a 2-week screening period. The effectiveness of the amnion dressing was estimated following 4 weeks of treatment. The wound assessment, based on a modified Bates-Jensen Questionnaire, revealed a good and satisfactory response to the treatment in 23 of the 25 patients. The measurement of MMP-2 and MMP-9 activities in wound exudates revealed a decrease in activity in response to amnion application. This effect resulted from the presence of the potent MMP inhibitors, tissue inhibitor of metalloproteinases-1 (TIMP-1), type-1 plasminogen activator inhibitor (PAI-1) and thrombospondin-1 (TSP-1) in the amnion dressings, as shown by real-time fluorescence zymography and protein microarrays. Thus, unlike modern synthetic dressing materials, radiation-sterilized amnion dressings may have a multidirectional beneficial effect on chronic wounds.

Upregulation of the WNT pathway in tuberous sclerosis-associated subependymal giant cell astrocytomas

Tuberous sclerosis (TS), autosomal dominant disorder manifested by the formation of usually benign tumors in the brain, heart, kidneys and skin, results from an inactivating mutation in one of two tumor suppressor genes TSC1 or TSC2. Protein products of these genes, hamartin and tuberin, respectively, have been shown to participate in the mTOR pathway controlling translation of approx. 10-15% of all proteins. In the current paper, we aimed at verifying whether hamartin and tuberin may also be implicated in the control of gene transcription. Very recently it has been hypothesized that the pathway triggered by WNT, one of embryonic growth factors involved in cell differentiation and migration, could be disturbed in TS. In order to test this hypothesis we evaluated samples of four subependymal giant cell astrocytomas (SEGAs), brain tumors developing in the progress of TS. We found that beta-catenin, transcription factor and mediator of WNT pathway activity is indeed present and active in SEGAs. mRNA transcripts for c-Myc and N-Myc, proteins whose transcription is regulated by beta-catenin, were upregulated in two of four SEGAs, while cyclin D1 mRNA was significantly higher in three SEGAs. At the same time, c-Myc and N-Myc proteins were detected in the same two samples. Thus, we show for the first time that aberrant WNT signaling may contribute to the pathogenesis of TS-associated SEGAs.

Reactive oxygen species and synthetic antioxidants as angiogenesis modulators: Clinical implications.

Angiogenesis is important for normal functioning of organism and its disturbances are observed in many diseases, called angiogenesis-related states. Reactive oxygen species (ROSs) play an important role in physiology, but high level of cellular ROSs is cytotoxic and mutagenic for the cells, i.e. it can lead to oxidative stress. In this review we discuss close relationship between ROSs and angiogenesis process. Substances counteracting free radicals or their action and oxidative stress are known as antioxidants. We postulate that antioxidants, by affecting angiogenesis, may modulate therapy results in the case of angiogenesis-related disease. Herein, we present some antioxidant preparations of synthetic (N-acetylcysteine, curcumin and its analogs, Probucol, oleane tripertenoid, EGCG synthetic analogs) and nature-identical (vitamin E and C) origin. Then, we analyze their angiogenic properties and their multidirectional molecular effect on angiogenesis. Most preparations reduce neovascularization and diminish the level of proangiogenic molecules, downregulating signaling pathways related to angiogenesis. Moreover, we discuss studies concerning anticancer properties of presented synthetic antioxidants and their application in several angiogenesis-related diseases. We conclude that therapy in angiogenesis-related diseases should be planned with consideration of the angiogenic status of the patient.

Immunomodulation on the ocular surface: a review

The increasing understanding of immune mechanisms changed our perception of the ocular surface, which is now considered a compartment of the common mucosal immune system. It offered the possibility to alter the physiological immune response on the ocular surface and effectively combat inflammation, which impairs stability of the tear film and causes tear hyperosmolarity, causing symptoms of dry eye disease. The paper provides an overview of ocular surface anatomy and physiology, explains the underlying mechanisms of dry eye disease and discusses novel and promising treatment modalities, such as cyclosporine A, biological therapies using autologous serum and various growth factors as well as experimental treatment methods which are currently being investigated.

Angiomodulatory properties of Rhodiola spp. and other natural antioxidants.

Disturbances of angiogenesis and oxidative stress can lead to many serious diseases such as cancer, diabetes or ischemic heart disease. Substances neutralizing oxidative stress are known as antioxidants. They can affect angiogenesis process also, and thus, they modulate therapy results. Antioxidants become more and more frequently used in order to maintain homeostasis of the organism and diminish the risk of disease. Herein, we introduce some antioxidant preparations of natural plant origin (Rhodiola, Aloe vera, Resveratrol, Echinacea, Plumbagin) and antioxidant supplements (Padma 28, Reumaherb, Resvega). Analyses of their angiogenic properties, their multidirectional molecular effect on angiogenesis as well as medical application are within the scope of this review. Most of presented preparations down regulate neovascularization. They can be safely administered to patients with abnormally high angiogenesis. Rhodiola modulates, and Echinacea, Aloe vera and Plumbagin inhibit tumour-related angiogenesis in vitro and in vivo (animal models). Resveratrol and Resvega reduce neovascularization in the eye and may be applicable in eye disorders. Padma 28 preparation exhibits angioregulatory activity, decreasing high angiogenesis of cancer cells and increasing physiological angiogenesis, therefore can be used in therapy of patients with various disturbances of angiogenesis. Antioxidant application in the case of angiogenesis-related diseases should take into consideration angiogenic status of the patient.

Spleen content of selected polyphenols, splenocytes morphology and function in mice fed Rhodiola kirilowii extracts during pregnancy and lactation.

UNLABELLED The genus Rhodiola (Crassulaceae) consists of many species, growing mainly in Asia and traditionally used as adaptogens and anti-inflammatory drugs. In order to elaborate herbal immunostimulator which could be safely given to pregnant women, we performed a study on immunotropic effects of feeding pregnant and lactating mice Rhodiola kirilowii extracts. This paper presents the results of the first part of our study - spleen content of selected polyphenols, spleen cellularity, splenocytes phenotype and their response to mitogens. Experiments were performed on adult inbred females of Balb/c strain, mated with adult males. Females, since copulatory plug was noted, up to the 28-th day after delivery were fed daily with 20 mg/kg b.m. water (RKW) or hydro-alcoholic (RKW-A) extracts of Rhodiola kirilowii. RESULTS 1. Significantly lower proportion of pregnant mice in experimental groups than in the control. 2. Cellularity of spleen and flavonol quercetin spleen concentration were significantly lower in experimental groups in comparison to the controls. 3. Flavanols ((+)-catechin and epicatechin) levels were significantly higher in the spleens of experimental mice than in the controls. 4. Positive correlation between spleen cellularity and quercetin, and negative correlation between spleen cellularity and epicatechin content were observed. 5. Spleen mass and spleen lymphocytes phenotype and proliferation in RKW and RKW-A fed mice did not differ from the control. These results, together with suspicion of some embryo-toxicity, are worrying and eliminate the possibility of use Rhodiola kirilowii extracts for long-term treatment in pregnant females.

Oral administration of Aloe vera gel, anti-microbial and anti-inflammatory herbal remedy, stimulates cell-mediated immunity and antibody production in a mouse model.

Introduction Aloe vera (L.) Burm. f. (Aloe barbadensis Mill) Liliaceae, succulent plant native to northern Africa, is presently cultivated in many regions of the world. Traditionally, its inner part of parenchyma, which contains aloe gel, was used for the treatment of minor wounds, inflammatory skin disorders, thermal and radiation burns and to alleviate chronic osteoarthritis pain. It also possesses some antimicrobial activity. Now, aloe gel is also increasingly consumed as a dietary supplement. Some data suggest its immunomodulatory properties. The aim of the study The aim of the study was to evaluate the influence of orally administered aloe gel on some parameters of cellular and humoral immunity viz. mitogen-induced proliferation of splenic lymphocytes and their chemokinetic activity, and anti-sheep red blood cells (SRBC) antibody production in Balb/c mice. Results Daily treatment of mice for 14 and 21 days with 50 µl or 150 µl of aloe gel dose resulted in enhanced chemokinetic activity and stronger response of their splenic lymphocytes to mitogen PHA and enhancement of anti-SRBC antibody production.

Inhibition of proliferation, migration and invasiveness of endothelial murine cells culture induced by resveratrol.

Angiogenesis is a multi-stage process of new vessel development which involves migration, proliferation and differentiation of endothelial cells. Pathological angiogenesis plays a crucial role in the pathomechanism of various ischemic, malignant and inflammatory disorders. Among eye diseases, macular degeneration (AMD) and proliferative diabetic retinopathy are a major public health issue as the most common causes of blindness. Since angiogenesis plays a crucial role in these conditions, there has been an increased interest in evaluating anti-angiogenic agents in their treatment. The polyphenol resveratrol found in the skin of red grapes, red wine, peanuts and other natural sources, controls proliferation of the cells, induces differentiation and induces apoptosis in various malignant cell lines. Modulation of angiogenesis by this compound has been considered as a very exciting topic and subject of further investigations. The aim of our study was in vitro assessment of resveratrols influence on proliferation, migration and invasion of an immortalized murine endothelial cell line from peripheral lymph node HEC clone a10. Resveratrol was shown to inhibit the proliferation of the endothelial cells in MTT (at 1, 10 and 50 µM) and AlamarBlue (at 50 µM) assays, and at a concentration of 50 µM significantly inhibited migration of endothelial cells. A concentration-dependent decrease in invasion potential of endothelial cells incubated with resveratrol 10 µM and 50 µM was detected. These promising in vitro results might encourage investigators to test efficacy and safety of resveratrol more extensively in the clinical practice, as a natural and safe anti-angiogenic agent.

The Angiogenic Activity of Ascites in the Course of Ovarian Cancer as a Marker of Disease Progression

Ovarian cancer cells are able to create invasive implants in the peritoneum and their growth is directly associated with the angiogenetic potential. This effect is probably stimulated by vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8), which are both found in ascites. The aim of this study was to assess the influence of ascites produced by ovarian cancer on the angiogenesis. Peritoneal fluid was collected from patients with advanced ovarian cancer; cancer cells were separated from CD45+ leukocytes. Angiogenesis was assessed in mice, after intradermal injection of full cellular suspension together with supernatant or phosphate buffered saline, purified cancer cells suspension, or CD45+ leukocytes suspension. The angiogenesis index (AI) was assessed after 72 hours. VEGF and Il-8 were measured in the supernatant and cellular suspension. AI was the highest in the isolated cancer cells suspensions as well in the group stimulated with supernatant. Both VEGF and IL-8 were high in supernatants from ascites rich in cancer cells (>45%). A significant correlation was revealed between IL-8 concentration and AI. We conclude that ascites in patients with advanced ovarian cancer stimulates angiogenesis and this mechanism is dependent mostly on cancer cells activity and enhanced by cooperation with infiltrating leukocytes.

Feeding mice with Aloe vera gel diminishes L-1 sarcoma-induced early neovascular response and tumor growth.

Aloe vera (Aloe arborescens, aloe barbadensis) is a medicinal plant belonging to the Liliaceae family. Aloe vera gel prepared from the inner part of Aloe leaves is increasingly consumed as a beverage dietary supplement. Some data suggest its tumor growth modulatory properties. The aim of the present study was to evaluate in Balb/c mice the in vivo influence of orally administered Aloe vera drinking gel on the syngeneic L-1 sarcoma tumor growth and its vascularization: early cutaneous neovascular response, tumor-induced angiogenesis (TIA test read after 3 days), and tumor hemoglobin content measured 14 days after L-1 sarcoma cell grafting. Feeding mice for 3 days after tumor cell grafting with 150 μl daily dose of Aloe vera gel significantly diminished the number of newly-formed blood vessels in comparison to the controls. The difference between the groups of control and Aloe-fed mice (150 μl daily dose for 14 days) with respect to the 14 days’ tumor volume was on the border of statistical significance. No difference was observed in tumor hemoglobin content.