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Psoriasis and neurodegenerative diseases (NDs) are important medical, social and economic issues. The possible relationship of psoriasis and NDs has not been established yet. This study involved 60 patients with plaque-type psoriasis. Serum concentrations of fatty acid-binding protein 7 (FABP-7), glutamic acid (GA) and neurofilament light chain (NFL), which have been hardly studied in psoriasis before, were measured by ELISA before and after 12 weeks of treatment with acitretin or methotrexate. The concentration of FABP-7 and NFL in patients before the treatment was significantly higher than in the controls (p < 0.01, p < 0.001, respectively). After the treatment their concentration decreased, although FABP-7 did so insignificantly. The concentration of GA did not differ significantly between patients and controls and before and after the treatment but we found its negative correlation with CRP (p < 0.05). The duration of psoriasis does not seem to directly affect the risk of neurodegeneration and the severity only in patients with worse skin condition. Elevated FABP-7 and NFL, which are present in the brain, may be considered as potential indicators of NDs development in psoriatics, although it surely requires further research. GA might correspond with neuroinflammation in psoriasis. Systemic antipsoriatic therapy could be studied in order to improve cognitive impairment through lowering NDs biomarkers in some cases.

Psoriasis is one of the most common dermatoses, which shortens patients’ lives because of the wide comorbidity. However, little is known about its association with neurodegenerative diseases (NDs). We aimed to investigate whether psoriatics are at increased risk of NDs. 60 patients with plaque-type psoriasis were enrolled into the study. Serum concentrations of tau protein (MAPT), neuronal cell adhesion molecule (NrCAM) and neprilysin (NEP), which are NDs biomarkers and have been hardly studied in psoriasis before, were measured before and after 12 weeks of treatment with acitretin or methotrexate. NrCAM and NEP concentrations were significantly lower in patients than controls, whereas MAPT higher (all p

The development of cancer is a problem that has accompanied mankind for years. The growing number of cases, emerging drug resistance, and the need to reduce the serious side effects of pharmacotherapy are forcing scientists to better understand the complex mechanisms responsible for the initiation, promotion, and progression of the disease. This paper discusses the modulation of the particular stages of carcinogenesis by selected physiological factors, including: acetylcholine (ACh), peroxisome proliferator-activated receptors (PPAR), fatty acid-binding proteins (FABPs), Bruton's tyrosine kinase (Btk), aquaporins (AQPs), insulin-like growth factor-2 (IGF-2), and exosomes. Understanding their role may contribute to the development of more effective and safer therapies based on new binding sites.

Chronic kidney disease (CKD) is deemed to be a worldwide health concern connected with neurological manifestations. The etiology of central nervous system (CNS) disorders in CKD is still not fully understood, however particular attention is currently being paid to the impact of accumulated toxins. Indoxyl sulfate (IS) is one of the most potent uremic toxins. The purpose of the present study was to assess IS concentrations in the cerebellum, brainstem, cortex, hypothalamus, and striatum with hippocampus of rats chronically exposed to IS. To evaluate IS impact on neurochemical and behavioral alterations, we examined its influence on brain levels of norepinephrine, epinephrine, dopamine, serotonin and their metabolites, as well as changes in behavioral tests (open field test, elevated plus maze test, chimney test, T maze test, and splash test). Our results show the highest IS accumulation in the brainstem. IS leads to behavioral alterations involving apathetic behavior, increased stress sensitivity, and reduced locomotor and exploratory activity. Besides, IS contributes to the impairment of spatial memory and motor coordination. Furthermore, we observed reduced levels of norepinephrine, dopamine or serotonin, mainly in the brainstem. Our findings indicate that IS can be one of the crucial uremic factors responsible for altered mental status in CKD.

During the COVID-19 pandemic, disinfection became an integral part of everybody’s life in order to avoid spreading the coronavirus. In 2021, an original anonymous online survey was carried out. The questions concerned the usage of disinfectants. The study population included 56 subjects diagnosed by a physician with hand eczema (HE-derm group) and 114 subjects with no hand skin disease diagnosed by a specialist (non-derm). The HE and non-HE groups were distinguished. Nearly 80% of the HE group, and 10% of the non-HE group, experienced worsening of hand skin lesions caused by increased skin disinfection. HE-group respondents more often declared the occurrence of new hand skin symptoms, over 80% of the subjects of this group had more than 1 new symptom (compared to nearly 40% of the non-HE group). Exacerbations of the skin disease were more frequently observed by the HE group during the pandemic. There was a statistically significant decrease of the quality of life in the HE group compared to the non-HE group during the pandemic. The COVID-19 pandemic caused an increase in the prevalence of hand skin symptoms and deterioration of the skin condition. Education on appropriate disinfection techniques and skincare, as well as early dermatological intervention, might allow us to limit the development of hand skin diseases.

MM-129 is a novel inhibitor targeting BTK/PI3K/AKT/mTOR and PD-L1, as it possesses antitumor activity against colon cancer. To evaluate the safety profile of MM-129, we conducted a toxicity study using the zebrafish and rodent model. MM-129 was also assessed for pharmacokinetics features through an in vivo study on Wistar rats. The results revealed that MM-129 exhibited favorable pharmacokinetics with quick absorption and 68.6% of bioavailability after intraperitoneal administration. No serious adverse events were reported for the use of MM-129, confirming a favorable safety profile for this compound. It was not fatal and toxic to mice at an anticancer effective dose of 10 μmol/kg. At the end of 14 days of administering hematological and biochemical parameters, liver and renal functions were all at normal levels. No sublethal effects were either detected in zebrafish embryos treated with a concentration of 10 μM. MM-129 has the potential as a safe and well-tolerated anticancer formulation for future treatment of patients with colon cancer.

Simple Summary Recently, mechanisms that lead to immune escape by cancer cells have been under great investigation. Elements involved in the tryptophan metabolism pathway and its derivatives are considered factors that play a wide role in silencing the immune system. However, it seems that those agents contribute to tumorigenesis through a direct impact on cancer cells. This study aimed to gather available data about the kynurenine pathway and its modulating effects on disease development through the impact on immune and cancer cells. This allows for an understanding of the complexity of this metabolic pathway in the context of carcinogenesis and indicates ambiguities that may explain the current failure of therapy with the use of compounds inhibiting tryptophan metabolism. The collected data not only help us to understand the pathogenesis of cancer but also provide the basis for the development of new therapeutic strategies in oncology. Abstract Background: The recently discovered phenomenon that cancer cells can avoid immune response has gained scientists’ interest. One of the pathways involved in this process is tryptophan (TRP) metabolism through the kynurenine pathway (KP). Individual components involved in TRP conversion seem to contribute to cancerogenesis both through a direct impact on cancer cells and the modulation of immune cell functionality. Due to this fact, this pathway may serve as a target for immunotherapy and attempts are being made to create novel compounds effective in cancer treatment. However, the results obtained from clinical trials are not satisfactory, which raises questions about the exact role of KP elements in tumorigenesis. An increasing number of experiments reveal that TRP metabolites may either be tumor promoters and suppressors and this is why further research in this field is highly needed. The aim of this study is to present KP as a modulator of cancer development through multiple mechanisms and to point to its ambiguity, which may be a reason for failures in treatment based on the inhibition of tryptophan metabolism

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths in men and in women. The impact of the new pyrazolo[4,3-e]tetrazolo[1,5-b][1,2,4]triazine sulphonamide (MM-129) was evaluated against human colon cancer in vitro and in zebrafish xenografts. Our results show that this new synthesised compound effectively inhibits cell survival in BTK-dependent mechanism. Its effectiveness is much higher at a relatively low concentration as compared with the standard chemotherapy used for CRC, i.e. 5-fluorouracil (5-FU). Flow cytometry analysis after annexin V-FITC and propidium iodide staining revealed that apoptosis was the main response of CRC cells to MM-129 treatment. We also found that MM-129 effectively inhibits tumour development in zebrafish embryo xenograft model, where it showed a markedly synergistic anticancer effect when used in combination with 5-FU. The above results suggest that this novel heterofused 1,2,4-triazine derivative may be a promising candidate for further evaluation as chemotherapeutic agent against CRC.

The progression of chronic kidney disease (CKD) in children is associated with deregulated parathyroid hormone (PTH), growth retardation, and low bone accrual. PTH can cause both catabolic and anabolic impact on bone, and the activating transcription factor 4 (ATF4), a downstream target gene of PTH, is related to its anabolic effect. Osteoprotegerin (OPG) and receptor activator of NF-κB ligand (RANKL) are PTH-dependent cytokines, which may play an important role in the regulation of bone remodeling. This study aimed to evaluate the impact of endogenous PTH and the bone RANKL/OPG system on bone growth, cross-sectional geometry and strength utilizing young, nephrectomized rats. The parameters of cross-sectional geometry were significantly elevated in rats with CKD during the three-month experimental period compared with the controls, and they were strongly associated with serum PTH levels and the expression of parathyroid hormone 1 receptor (PTH1R)/ATF4 genes in bone. Low bone soluble RANKL (sRANKL) levels and sRANKL/OPG ratios were also positively correlated with cross-sectional bone geometry and femoral length. Moreover, the analyzed geometric parameters were strongly related to the biomechanical properties of femoral diaphysis. In summary, the mild increase in endogenous PTH, its anabolic PTH1R/ATF4 axis and PTH-dependent alterations in the bone RANKL/OPG system may be one of the possible mechanisms responsible for the favorable impact on bone growth, cross-sectional geometry and strength in young rats with experimental CKD.

Recombinant human erythropoietin (Epo) is an effective and convenient treatment for cancer-related anaemia. In our study for the first time, we evaluated the effect of simultaneous use of Epo and Bruton’s tyrosine kinase (BTK) inhibitor LFM-A13 on the viability and tumour development of breast cancer cells. The results demonstrated that Epo significantly intensifies the anticancer activity of LFM-A13 in MCF-7 and MDA-MB-231. The featured therapeutic scheme efficiently blocked the tumour development in zebrafish experimental cancer model. Epo and LFM-A13 administered together resulted in effective cell killing, accompanied by attenuation of the BTK signalling pathways, loss of mitochondrial membrane potential (MMP), accumulation of apoptotic breast cancer cells with externalised PS, a slight increase in phase G0/G1 and a reduction in cyclin D1 expression. Simultaneous use of Epo with LFM-A13 inhibited early stages of tumour progression. This therapeutic scheme may be rationale for further possible research.

Novel transition metal complexes (Au, Pd, Pt) with berenil and 2-(1-methyl-5-nitroimidazol-2-yl)ethanol were obtained through two-step synthesis. The cytotoxicity assay against MCF-7 and MDA-MB-231 breast cancer cells revealed that novel platinum and palladium complexes cause a reduction on the viability of MCF-7 and MDA-MB-231 breast cancer cells to a greater extent than cisplatin. The complexes showed lower cytotoxicity on normal MCF-10A human breast epithelial cells than on tumor cells. Furthermore, we observed that these complexes selectively concentrate in tumor cell mitochondria due to the characteristic for these cells increased membrane potential that may explain their increased proapoptotic activity. The activity of the synthesized compounds against topoisomerase type II&alpha, and their increased impact on DNA defragmentation also were documented. The novel complexes also induced autophagosome changes and inhibited tumor growth in xenograft models (established using breast cancer cells).

One of the main mechanisms for avoiding immune response by cancer cells is by inducing an immunosuppressive environment in the tumor, following the activation of immune checkpoints i.e. PD-1 or CTLA-4 receptor inhibitors on T lymphocytes. Inhibiting the interaction between PD-1 or CTLA-4 and their ligands (PD-L1, CD80, and CD85) leads to unblocking T-lymphocyte function, and thus destroying cancer cells. Certain intracellular signaling pathways are also involved in the development of tumor cell immunoresistance. Blocking the activation of immunosuppressive pathways may increase immunological anti-tumor control

Chronic kidney disease (CKD) occurrence is rising all over the world. Its presence is associated with an increased risk of premature death from cardiovascular disease (CVD). Several explanations of this link have been put forward. It is known that in renal failure, an array of metabolites cannot be excreted, and they accumulate in the organism. Among them, some are metabolites of tryptophan (TRP), such as indoxyl sulfate and kynurenine. Scientists have become interested in them in the context of inducing vascular damage in the course of chronic kidney impairment. Experimental evidence suggests the involvement of TRP metabolites in the progression of chronic kidney disease and atherosclerosis separately and point to oxidative stress generation as one of the main mechanisms that is responsible for worsening those states. Since it is known that blood levels of those metabolites increase significantly in renal failure and that they generate reactive oxygen species (ROS), which lead to endothelial injury, it is reasonable to suspect that products of TRP metabolism are the missing link in frequently occurring atherosclerosis in CKD patients. This review focuses on reports that shed a light on TRP metabolites as contributing factors to vascular damage in the progression of impaired kidney function.

Background and Purpose Bruton's tyrosine kinase (BTK) is a non-receptor tyrosine kinase involved in the activation of signaling pathways responsible for cell maturation and viability. BTK has previously been reported to be overexpressed in colon cancers. This kind of cancer is often accompanied by anemia, which is treated with an erythropoietin supplement. The goal of the present study was to assess the effects of combination therapy with erythropoietin beta (Epo) and LFM-A13 (BTK inhibitor) on colon cancer in in vitro and in vivo models. Experimental Approach DLD-1 and HT-29 human colon adenocarcinoma cells were cultured with Epo and LFM-A13. Cell number, cell viability, expression of EpoR, BTK, Akt at mRNA, and protein levels were assessed. Nude mice were inoculated with adenocarcinoma cells and treated with Epo and LFM-A13. Key Results Simultaneous use of Epo and LFM-A13 exerts a mostly synergistic inhibitory effect on colon cancer cell growth. The featured therapeutic scheme resulted in effective cell killing, accompanied by attenuation of the BTK signaling pathways. Epo+LFM-A13 also prevented the normal process of microtubule assembly during mitosis via the down-regulation of PLK1 expression. The combined administration of Epo and LFM-A13 significantly reduced the growth rate of tumor cells, while it showed high-profile safety with no induced nephrotoxicity, hepatotoxicity, or changes in the hematological parameters. Conclusion and Implications Our findings demonstrate that Epo significantly enhances the antitumor activity of LFM-A13, indicating the potential use of a combination of Epo and LFM-A13 as an effective therapeutic approach for patients with colorectal cancer.

SummaryThis study provides new information on the cellular effects of 1,3,5-triazine nitrogen mustards with different peptide groups in DLD and Ht-29 human colon cancer cell lines. A novel series of 2,4,6-trisubstituted 1,3,5-triazine derivatives bearing 2-chloroethyl and oligopeptide moieties was designed and synthesized. The most cytotoxic derivative was triazine with an Ala-Ala-OMe substituent on the ring (compound 7b). This compound induced time- and dose-dependent cytotoxicity in the DLD-1 and HT-29 colon cancer cell lines. The triazine derivative furthermore induced apoptosis through intracellular signaling pathway attenuation. Compound 7b may be a candidate for further evaluation as a chemotherapeutic agent against colorectal cancer.

Simple Summary The most important biological function of vitamin B12 (cobalamin) is to accomplish DNA synthesis, which is necessary for cell division. Cobalamin deficiency may be especially acute for rapidly dividing cells, such as glioblastoma cells. Therefore, cobalamin antagonists offer a medicinal potential for developing anti-glioma agents. In the present study, we revealed, for the first time, that the induction of cobalamin deficiency by vitamin B12 antagonist with affinity to key transporter of cobalamins, inhibited glioblastoma cells growth and promoted cell cycle arrest. The effect was observed for non-toxic concentration of the agent, as demonstrated on zebrafish. Moreover, as compared to our previous study, the cytostatic effect of the agent was more pronounced in glioblastoma cells than in normal astrocytes. We believe that the study may become the basis for further in vitro and in vivo experiments concerning cobalamin deprivation as a potential therapeutic strategy for glioblastoma. Abstract The most important biological function of vitamin B12 is to accomplish DNA synthesis, which is necessary for cell division. Cobalamin deficiency may be especially acute for rapidly dividing cells, such as glioblastoma cells. Therefore, cobalamin antagonists offer a medicinal potential for developing anti-glioma agents. In the present study, we developed an in vitro model of cobalamin deficiency in glioblastoma cells. Long-term treatment of cells with the cobalamin analogue, hydroxycobalamin [c-lactam] (HCCL) was applied to induce an increase of hypocobalaminemia biomarker. Cytometric assays demonstrated that vitamin B12 promoted glioblastoma cells proliferation, whereas the treatment of cells with HCCL caused a dramatic inhibition of cell proliferation and an induction of cell cycle arrest at the G2/M phase. Vitamin B12 counteracted all the observed effects of HCCL. In the in silico study, we characterized the molecular interactions between HCCL and transcobalamin II (TCII). We have demonstrated that HCCL shares similar interactions with TCII as naturally occurring cobalamins and therefore may act as a competitive inhibitor of this key transporter protein. We assessed the impact of HCCL on the mortality or developmental malformations of zebrafish embryos. Collectively, our findings suggest that the use of cobalamin transport antagonists as potential anti-glioma agents would be worth exploring further.

Purpose Numerous genetic and endocrine factors are involved in the process of testicular descent, but only a few genetic causes have been reported in human. The aim of this study was to investigate the density and distribution of single nucleotide polymorphisms (SNPs) anti-Mullerian hormone (AMH) and AMHRII receptors in cryptorchid patients and determine potential hormone imbalance connected with undescended testes by assessing the levels of AMH, Insulin-like factor 3 (INSL3) and inhibin B. Materials and methods The serum hormone levels (AMH, INSL3 and inhibin B) were compared in the two groups – cryptorchidism ( n = 105) and control group ( n = 58). The frequency of AMHRII −482 A > G, AMHRII IVS 10 + 77 A > G, AMHRII IVS 5–6 C > T, and AMH Ile49Ser polymorphisms among cryptorchid boys were compared with the control group. Results None of the hormones levels were different between the cryptorchid and the control groups. All cases of IVS 5–6 C > T homozygote and heterozygote mutation were accompanied by an IVS 10 + 77 A > G and 482 A > G homozygote and heterozygote mutation. Interestingly, in most cases of all four polymorphisms, homozygote recessive genotype was associated with cases of cryptorchidism. However, the groups of patients were too small to draw definite conclusions. Conclusion The AMHRII −482 A > G, AMHRII IVS 10 + 77 A > G, AMHRII IVS 5–6 C > T and AMH Ile49Ser genotypes should be determined in a much larger group of boys with cryptorchidism.

Background Aliskiren is the first orally active inhibitor of renin to be approved for clinical use as an antihypertensive agent. A number of studies show a link between aliskiren and intravascular thrombosis. Materials and methods The goal of the present study was to investigate the impact of aliskiren on arterial thrombosis in normotensive and renovascular hypertensive rats. The contribution of each coagulation and fibrinolytic parameters in the mode of aliskiren action was determined. Six weeks after clipping of the left renal artery rats developed hypertension which was confirmed by the “tail cuff” method. Animals were treated with aliskiren (10, 30 and 100 mg/kg/day) per os for 10 days. Arterial thrombosis was induced by electrical stimulation of the common carotid artery. Results It was found that aliskiren in a dose-dependent manner decreased weight of the arterial thrombus in normotensive and hypertensive rats. It has been shown that this result was not associated with the effects on blood pressure, TF, PT, APTT, fibrinogen and hematological parameters. It was found that aliskiren caused increase of t-PA activity and decrease of its inhibitor activity. Conclusions The presented results indicate that aliskiren inhibits hemostasis in the arterial thrombosis in rats. The antithrombotic effect is related with improvement of the fibrinolytic balance, and also depends on antiplatelet action.

Background and Purpose Bruton's tyrosine kinase (Btk) is a non‐receptor tyrosine kinase involved in the activation of signalling pathways responsible for cell maturation and viability. Btk has previously been reported to be overexpressed in colon cancers. This kind of cancer is often accompanied by anaemia, which is treated with an erythropoietin supplement. The goal of the present study was to assess the effects of combination therapy with erythropoietin β (Epo) and LFM‐A13 (Btk inhibitor) on colon cancer in in vitro and in vivo models. Experimental Approach DLD‐1 and HT‐29 human colon adenocarcinoma cells were cultured with Epo and LFM‐A13. Cell number and viability, and mRNA and protein levels of Epo receptors, Btk and Akt were assessed. Nude mice were inoculated with adenocarcinoma cells and treated with Epo and LFM‐A13. Key Results The combination of Epo and LFM‐A13 mostly exerted a synergistic inhibitory effect on colon cancer cell growth. The therapeutic scheme used effectively killed the cancer cells and attenuated the Btk signalling pathways. Epo + LFM‐A13 also prevented the normal process of microtubule assembly during mitosis by down‐regulating the expression of Polo‐like kinase 1. The combination of Epo and LFM‐A13 significantly reduced the growth rate of tumour cells, while it showed high safety profile, inducing no nephrotoxicity, hepatotoxicity or changes in the haematological parameters. Conclusion and Implications Epo significantly enhances the antitumour activity of LFM‐A13, indicating that a combination of Epo and LFM‐A13 has potential as an effective therapeutic approach for patients with colorectal cancer.

Background: Cancer patients treated with alkylating agents and radiotherapy are exposed to high level of reactive oxygen species (ROS) in tissues. ROS can involve superoxide free radicals, peroxynitrite, singlet oxygen, nitric oxide and hydrogen peroxide. It is well documented that increased exposure to oxygen through a high metabolic rate could lead to a shortened life span. Ionizing radiation, use of drugs and the development of cancer can lead to cancer-induced anemia. Recombinant human erythropoietin (Epo) supplementation is one of the methods for treating anemia. Erythropoietin through an increase in the number of erythrocytes, improves oxygenation tissue. The aim of this work was to study the effect of Epo on colon adenocarcinoma cells (DLD-1) given alone or in combination with hydrogen peroxide (H2O2). Cell proliferation and number were measured. Methods: Expression of EpoR, Bcl-2 and Akt1 protein was assessed by RT-PCR, Western blot, and confocal microscopy. Results: The results show that the coadministration of Epo and H2O2 indicates antitumor action, which occurs via a dose-dependent inhibition of DLD-1 cell growth and proliferation. Moreover, the coadministration of Epo and H2O2 resulted in a decrease of cell numbers, as well as Bcl-2 expression. The incubation of DLD-1 cells with those agents led to a decrease in EpoR and phosphorylated EpoR expression and an increase in Akt1 and phosphorylated Akt expression. The addition of Epo to H2O2 intensified the cytotoxic effect of the latter. Conclusion: These preclinical results suggest that Epo during chemotherapy or radiotherapy may possess potential benefits in colon cancer patients.

The Bruton’s tyrosine kinase (BTK) inhibitor LFM-A13 has been widely employed as an antileukemic agent, but applications in solid cancer have been found recently. The compound promotes apoptosis, has an antiproliferative effect, and increases cancer cell sensitivity to chemotherapy drugs. We decided to assess the impact of the simultaneous use of erythropoietin (Epo) and LFM-A13 on signal transduction in colon DLD-1 and HT-29 cells, as well as in tumor xenografts. The induction of apoptosis by Epo and LFM-A-13 in the cells was confirmed by phosphatidylserine externalization, loss of mitochondrial membrane potential, and modulation of the expression of apoptotic protein BAX and antiapoptotic protein BCL-2 in colon adenocarcinoma cells. Nude mice were inoculated with adenocarcinoma cells and treated with Epo and LFM-A13 in order to evaluate the degree of tumor regression. The simultaneous use of Epo and LFM-A13 severely inhibited cell growth, activated apoptosis, and also inhibited tumor growth in xenografts. The addition of Epo to LFM-A13 intensified the antiproliferative effect of LFM-A13, confirmed by the loss of mitochondrial membrane potential and the accumulation of apoptotic colon cancer cells with externalized phosphatidylserine (PS). These preclinical results suggest that the combination of Epo and LFM-A13 has a high proapoptotic activity and should be tested in the clinic for the treatment of solid tumors such as colon cancer.

Introduction: ACE2 alternatively converts angiotensin (Ang) II into Ang-(1–7) and Ang I into Ang-(1–9). There is little information in the literature with respect to Ang-(1–9) properties. A number of studies show a link between peptides of the renin-angiotensin system and thrombosis. Materials and methods: We have investigated the influence of Ang-(1–9) on stasis-induced venous thrombosis in the rat. The contribution of coagulation and fibrinolytic systems, angiotensin receptor type 1 (AT 1 ) and MAS receptor in the mode of Ang-(1–9) action was also determined. Results: Ang-(1–9) enhanced thrombosis development, decreased plasma concentration of tissue plasminogen activator and increased the level of its inhibitor (PAI-1). The action of Ang-(1–9) was reversed by selective antagonist of AT 1 receptor, but not Ang-(1–7) antagonist. Ang-(1–9) did not bind to the AT 1 receptor. Conclusions: Ang-(1–9) enhances venous thrombosis in the rat because of the impairment of fibrinolysis. The prothrombotic effect of Ang-(1–9) is mediated by Ang II acting via the AT 1 receptor.

A substantial amount of evidence links the renin-angiotensin system with thrombosis. For example, ACE inhibitors and angiotensin receptor blockers possess independent of the hemodynamic changes, antithrombotic activity. Aliskiren direct renin inhibitor belongs to a new very promising antihypertensive drug that effectively inhibits the renin-angiotensin system. The aim of study was to determine the influence of aliskiren on stasis-induced venous thrombosis in renovascular hypertensive and normotensive rats. The involvement of nitric oxide and prostacyclin in the potential antithrombotic action was also elucidated. Six weeks after clipping of the left renal artery rats developed hypertension which was confirmed by the "tail cuff" method. Hypertensive and normotensive rats were treated with aliskiren (10, 30 and 100mg/kg/day) per os for 10days. Venous thrombosis was induced by stasis of vena cava inferior. Aliskiren at the highest dose induced a significant decrease in systolic blood pressure in hypertensive, but did not change this parameter in normotensive rats. Oral administration of aliskiren resulted in dose-dependent decrease of venous thrombus weight in hypertensive and normotensive rats. The antithrombotic activity of aliskiren was abolished both by NO synthase inhibitor and prostacyclin synthesis inhibitor. Aliskiren decreased collagen-induced platelet aggregation, increased plasma level of tissue plasminogen activator activity whereas no changes in plasminogen activator inhibitor activity and coagulation parameters were found. We showed that aliskiren prevents the development of venous thrombosis by enhanced fibrinolysis and the blood platelet inhibition via nitric oxide and/or prostacyclin-dependent mechanism.

Anemia is a relatively common symptom coexisting with colorectal carcinoma. Besides having a positive impact on hematological parameters, erythropoietin (Epo) has the serious adverse effect of promoting the neoplastic process. The role of Epo in colon cancer has not been clearly shown. The aim of this study was to assess the effects of Epo therapy on colorectal carcinoma cells both in in vitro and in animal models. Human colon adenocarcinoma cells DLD-1 and Ht-29 were cultured in medium with Epo beta in normoxia. Cell proliferation was measured with an automated cell counter. Expression of erythropoietin receptor (EpoR) mRNA, Akt mRNA, and their proteins were assessed by RT-PCR and confocal microscopy, respectively. Nude mice were inoculated with adenocarcinoma cells and treated with a therapeutic dose of Epo. Expression of EpoR, VEGF, Flt-1 and CD31 was evaluated in xenograft tumors. We identified that Epo through EpoR activates Akt, which promotes colon cancer cell growth and proliferation. Epo, and high levels of phosphorylated EpoR, directly accelerates tumor growth through its proliferative and proangiogenic effects. This study demonstrated that Epo had enhanced carcinogenesis through increase of EpoR and Flt-1 expression, and thereby contributed to tumor development. These results suggest that both EpoR-positive and EpoR-negative cancer cells could be regulated by exogenous Epo. However, an increased response to erythropoietin was observed in the EpoR-positive cells. Thus, erythropoietin increases the risk of tumor progression in colon cancer and should not be used to treat anemia in this type of cancer.