Gasdermin D (GSDMD) Is Upregulated in Psoriatic Skin-A New Potential Link in the Pathogenesis of Psoriasis.

Psoriasis is an important issue in daily dermatological practice. Not only is it an aesthetic defect but it is also a matter of decreased life quality and economic burden. However frequent, the pathogenesis of psoriasis remains uncertain despite numerous investigations. Gasdermins are a family of six proteins. Gasdermin D (GSDMD) is the best-studied from this group and is involved in the processes of inflammation, proliferation, and death of cells, especially pyroptosis. GSDMD has never been studied in psoriatic sera or urine before. Our study involved 60 patients with psoriasis and 30 volunteers without dermatoses as controls. Serum and urinary GSDMD concentrations were examined by ELISA. The tissue expression of GSDMD was assessed by immunohistochemistry. The serum-GSDMD concentration was insignificantly higher in the patients than controls. There were no differences in the urinary-GSDMD concentrations between the patients and controls. Strong tissue expression of GSDMD was significantly more prevalent in psoriatic plaque than in the non-lesional skin and healthy skin of the controls. There was no correlation between the serum-GSDMD concentrations and the psoriasis severity in PASI, age, or disease duration. Taking into consideration the documented role of gasdermins in cell proliferation and death, the increased expression of GSDMD in psoriatic skin may demonstrate the potential involvement of this protein in psoriasis pathogenesis. Neither serum, nor urinary GSDMD can be currently considered a psoriasis biomarker; however, future studies may change this perspective.

Serum PTH, PTH1R/ATF4 pathway, and the sRANKL/OPG system in bone as a new link between bone growth, cross-sectional geometry, and strength in young rats with experimental chronic kidney disease.

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.

Exploration of novel heterofused 1,2,4-triazine derivative in colorectal cancer.

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.

Paracrine Kynurenic Pathway Activation in the Bone of Young Uremic Rats Can Antagonize Anabolic Effects of PTH on Bone Turnover and Strength through the Disruption of PTH-Dependent Molecular Signaling.

Secondary hyperparathyroidism and abnormalities in tryptophan (TRP) metabolism are commonly observed in chronic kidney disease (CKD). The present study aimed to establish potential interactions between endogenous parathyroid hormone (PTH) and activation of the bone kynurenine (KYN) pathway in relation to bone turnover and strength in young rats after one month (CKD-1) and three months (CKD-3) of experimental CKD. TRP, KYN, KYN/TRP ratio and bone turnover markers (BTMs) were measured in trabecular and cortical bone tissue. Expression of aryl hydrocarbon receptor (AhR) and the genes involved in osteogenesis was determined in femoral bone. Biomechanical testing of femoral diaphysis and femoral neck was also performed. Activation of the KYN pathway in trabecular bone during CKD development intensified the expression of genes related to osteogenesis, which led to a decrease in cyclic adenosine monophosphate (cAMP) and BTMs levels, resulting in a stiffer and mechanically weaker femoral neck. In contrast, reduction of the KYN pathway in cortical bone allowed to unblock the PTH-dependent anabolic activating transcription factor 4/parathyroid hormone 1 receptor (PTH1R/ATF4) axis, led to cAMP accumulation, better bone turnover and strength in the course of CKD development. In summary, the paracrine KYN pathway in bone can interfere with the anabolic effects of PTH on bone through disrupting PTH-dependent molecular signaling.

The intensification of anticancer activity of LFM-A13 by erythropoietin as a possible option for inhibition of breast cancer.

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.

Modulation of the Paracrine Kynurenic System in Bone as a New Regulator of Osteoblastogenesis and Bone Mineral Status in an Animal Model of Chronic Kidney Disease Treated with LP533401.

An increase in the peripheral synthesis of serotonin and kynurenine, observed during the chronic kidney disease (CKD) course, is negatively associated with bone health. Serotonin and kynurenine are connected by the common precursor, tryptophan. LP533401 is an inhibitor of peripheral serotonin synthesis. This study aimed to establish if the inhibition of serotonin synthesis by LP533401 may affect the kynurenine pathway activity in bone tissue and its potential consequence with regard to osteogenesis and bone mineral status. Nephrectomized rats were treated with LP533401 at a dose of 30 and 100 mg/kg daily for eight weeks. Tryptophan and kynurenine concentrations were determined, and tryptophan 2,3-dioxygenase (TDO) expression was assessed. We discovered the presence of a TDO-dependent, paracrine kynurenic system in the bone of rats with CKD. Its modulation during LP533401 treatment was associated with impaired bone mineral status. Changes in TDO expression affecting the kynurenine pathway activity were related to the imbalance between peripheral serotonin and 25-hydroxyvitamin D. There were also close associations between the expression of genes participating in osteoblastogenesis and activation of the kynurenine pathway in the bones of LP53301-treated rats. Our results represent the next step in studying the role of tryptophan metabolites in renal osteodystrophy.

Gasdermin B (GSDMB) in psoriatic patients-a preliminary comprehensive study on human serum, urine and skin.

Psoriasis is one of the most common skin diseases and a crucial issue to manage in contemporary dermatology. The search for the details of its pathogenesis, markers and treatment is continuously ongoing. Our aim was to investigate the role of gasdermin B (GSDMB) in psoriasis, the second protein from the gasdermin family, involved in cell death and proliferation. GSDMB serum and urinary concentrations have never been studied in psoriatics, neither tissue expression of GSDMB by immunohistochemistry. The study included 60 psoriatic patients and 30 volunteers without dermatoses as controls. The serum and urinary GSDMB were evaluated by ELISA. Tissue expression of GSDMB was analyzed by immunohistochemistry. The serum and absolute urine concentrations of GSDMB were significantly higher in psoriatic patients than controls without skin diseases (p = 0.0137, p = 0.039 respectively). Urinary GSDMB/creatinine concentration ratio was significantly lower in patients compared to controls (p = 0.0241). The expression of GSDMB in the dermis and epidermis was significantly more prevalent in psoriatic plaque compared to the non-lesional skin and healthy skin of controls (p = 0.0012, p = 0.017, respectively). Serum GSDMB correlated positively with the age of patients (R = 0.41; p = 0.001). Our study adds to the current state of knowledge about psoriasis concerning the potential involvement of GSDMB. Possibly it could be engaged in keratinocytes migration, which requires further research. Elevated serum GSDMB and decreased urinary GSDMB/creatinine concentration ratio could potentially be investigated as psoriasis biomarkers. GSDMB could be investigated in the future as a potential therapeutic target.

Dose-dependent exposure to indoxyl sulfate alters AHR signaling, sirtuins gene expression, oxidative DNA damage, and bone mineral status in rats.

Indoxyl sulfate (IS), an agonist of aryl hydrocarbon receptors (AhR), can accumulate in patients with chronic kidney disease, but its direct effect on bone is not clear. The present study investigated the effect of chronic exposure to low (100 mg/kg b.w.; 100 IS) and high (200 mg/kg b.w.; 200 IS) dose of IS on bone AhR pathway, sirtuins (SIRTs) expression, oxidative DNA damage and bone mineral status in Wistar rats. The accumulation of IS was observed only in trabecular bone tissue in both doses. The differences were observed in the bone parameters, depending on the applied IS dose. The exposure to 100 IS increased AhR repressor (AhRR)-CYP1A2 gene expression, which was associated with SIRT-1, SIRT-3 and SIRT-7 expression. At the low dose group, the oxidative DNA damage marker was unchanged in the bone samples, and it was inversely related to the abovementioned SIRTs expression. In contrast, the exposure to 200 IS reduced the expression of AhRR, CYP1A, SIRT-3 and SIRT-7 genes compared to 100 IS. The level of oxidative DNA damage was higher in trabecular bone in 200 IS group. Femoral bone mineral density was decreased, and inverse relations were noticed between the level of trabecular oxidative DNA damage and parameters of bone mineral status. In conclusion, IS modulates AhR-depending signaling affecting SIRTs expression, oxidative DNA damage and bone mineral status in a dose dependent manner.

The Possible Effect of ß-Blocker Use on the Circulating MMP-2/TIMP-2 System in Patients with Chronic Kidney Disease on Conservative Treatment.

Background: The purpose of the study was to determine whether the use of ß-adrenoceptor antagonists (ß-blockers) can affect metalloproteinase 2 (MMP-2) and its tissue inhibitor (TIMP-2) in patients with chronic kidney disease (CKD) on conservative treatment. Methods: The circulating MMP-2/TIMP-2 system, proinflammatory cytokines (tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), and the marker of oxidative stress-Cu/Zn superoxide dismutase (Cu/Zn SOD)-were measured in 23 CKD patients treated with ß-blockers [ß-blockers (+)] and in 27 CKD patients not receiving the above medication [ß-blockers (-)]. Results: The levels of MMP-2, TIMP-2, and IL-6 were significantly lower in the ß-blockers (+) than in the ß-blockers (-) group, whereas Cu/Zn SOD concentrations were not affected by ß-blocker use. There was a strong, independent association between MMP-2 and TIMP-2 in both analyzed patient groups. In the ß-blockers (+) group, MMP-2 levels were indirectly related to the signs of inflammation, whereas in the ß-blockers (-) group, the alterations in the MMP-2/TIMP-2 system were associated with the oxidative stress marker and CKD etiology. Conclusions: This study is the first to suggest that the use of ß-blockers was associated with the reduction in IL-6 and the MMP-2/TIMP-2 system in CKD, providing a pharmacological rationale for the use of ß-blockers to reduce inflammation and abnormal vascular remodeling in CKD.

Tumor Necrosis Factor (TNF) α, Endothelin (ET) 1 and α1-Acid Glycoprotein (AGP) as Potential Urine and Serum Markers of Metabolic Complications in Psoriasis?

INTRODUCTION: Psoriasis, one of the most frequent dermatoses, strongly associated with metabolic disorders which increase patients' comorbidity and mortality. Hence, it is essential to look for markers of such complications. Our aim was to assess the clinical utility of urinary tumor necrosis factor alpha (TNFα), endothelin 1 (ET-1) and α1-acid glycoprotein (α1AGP) as well as their serum concentrations as markers of metabolic complications in psoriatics, and to examine the relations of these markers to clinical and demographic parameters. METHODS: The study involved 60 patients with plaque psoriasis and 30 volunteers without skin diseases (the control group). Serum and urinary concentrations of TNFα, ET-1 and α1AGP were measured by ELISA. Psoriasis severity was assessed using the psoriasis activity and severity index (PASI). Routine laboratory investigations were additionally performed. RESULTS: All serum markers were significantly higher in the patients compared to the controls. TNFα was undetectable in the urine in half of the patients. The urinary ET-1/creatinine concentration ratio was significantly lower in the psoriatics than the controls, whereas the absolute urinary α1AGP was significantly higher and the α1AGP/creatinine ratio was insignificantly different. There was no correlation between serum or urinary markers and PASI. All serum markers were higher in patients with psoriasis lasting less than 15 years. CONCLUSIONS: Serum TNFα, ET-1 and α1AGP seem to be useful biomarkers of metabolic syndrome in psoriatics. ET-1 could perhaps become a urinary marker of metabolic disorders in psoriatics, but further studies are required to confirm that a decreased ET-1 concentration in urine is a reliable predictive tool. Increased urinary α1AGP also requires more in-depth research as a potential marker. TNFα urine assessment does not seem to be useful for screening for metabolic disorders in psoriatics. Serum or urinary TNFα, ET-1 and α1AGP do not seem to be associated with psoriasis severity or duration.

Gasdermin E (GSDME)-A New Potential Marker of Psoriasis and Its Metabolic Complications: The First Combined Study on Human Serum, Urine and Tissue.

Psoriasis is a frequent and incurable skin disease whose pathogenesis is still not fully understood. It is characterized by immune disturbances leading to hyperproliferation and improper differentiation of keratinocytes. Gasdermin E (GSDME) is a protein from the gasdermin family involved in the processes of inflammation and cell death based on apoptosis, necroptosis and pyroptosis. It has never been studied in psoriatics' sera or urine before. Our study enrolled 60 patients with psoriasis and 30 volunteers without dermatoses as controls. Serum and urinary GSDME concentrations were examined by ELISA and tissue expression of GSDME by immunohistochemistry. Serum GSDME concentration was significantly higher in patients than controls (p < 0.05). There were no differences in urinary GSDME concentrations between patients and controls. GSDME expression was significantly higher in the psoriatic plaque than non-lesional patients' skin and compared to controls (both p < 0.001). There was no correlation between serum GSDME or its lesional expression and psoriasis severity, age or disease duration. GSDME serum concentration was significantly negatively correlated with BMI, triglycerides and glucose concentrations. The obtained results suggest the engagement of GSDME in psoriasis pathogenesis. It could potentially become a new non-invasive psoriasis marker. Considering its pro-apoptotic influence, GSDME could be compensatively elevated to direct cells towards apoptosis, whereas under other circumstances, it may lead to pyroptosis and sustain inflammation. GSDME may exert a protective influence on the metabolic complications in psoriasis which requires further studies.

Evaluation of Plasma Concentrations of Galectins-1, 2 and 12 in Psoriasis and Their Clinical Implications.

Psoriasis is a complex disease that nowadays is considered not only a dermatosis but a kind of systemic disorder associated with many accompanying diseases. Metabolic complications leading to cardiovascular incidences are the cause of increased mortality in psoriatic patients. Galectins (gal) are beta-galactoside-binding lectins that exert different functions, including engagement in metabolic processes. Our aim was to assess the concentrations of gal-1, 2 and 12 in psoriatics, to establish their potential clinical implications, including in metabolic complications. Plasma galectins were assessed by ELISA in 60 psoriatic patients and 30 controls without dermatoses and a negative family history of psoriasis. Plasma concentrations of all galectins were significantly higher in patients than controls (gal-1 with p < 0.001, gal-2 and 12 with p < 0.05). There were no correlations between galectins concentrations and psoriasis severity in PASI or disease duration (p > 0.05). Gal-1 and 12 were significantly negatively correlated with GFR (p < 0.05, p < 0.01, respectively) and gal-2 with HDL (p < 0.05). Gal-2 was significantly positively correlated with CRP (p < 0.05) and gal-12 with fasting glucose (p < 0.01). Based on the results and given the reported role of galectins in metabolic disorders we may conclude that gal-1, 2 and 12 could be potentially engaged in metabolic complications in psoriatics, most probably in atherosclerosis. Gal-2 could be perhaps further investigated as a marker of metabolically induced inflammation in psoriasis, gal-1 and gal-12 as predictors of renal impairment in psoriatics due to metabolic disorders. Potentially, gal-12 could be considered in the future as a marker of carbohydrate metabolism disorders in psoriatics.

Vitamin K-Dependent Carboxylation of Osteocalcin in Bone-Ally or Adversary of Bone Mineral Status in Rats with Experimental Chronic Kidney Disease?

Chronic kidney disease (CKD) commonly occurs with vitamin K (VK) deficiency and impaired bone mineralization. However, there are no data explaining the metabolism of endogenous VK and its role in bone mineralization in CKD. In this study, we measured serum levels of phylloquinone (VK1), menaquinone 4 and 7 (MK4, MK7), and VK-dependent proteins: osteocalcin, undercarboxylated osteocalcin (Glu-OC), and undercarboxylated matrix Gla protein (ucMGP). The carboxylated osteocalcin (Gla-OC), Glu-OC, and the expression of genes involved in VK cycle were determined in bone. The obtained results were juxtaposed with the bone mineral status of rats with CKD. The obtained results suggest that the reduced VK1 level observed in CKD rats may be caused by the accelerated conversion of VK1 to the form of menaquinones. The bone tissue possesses all enzymes, enabling the conversion of VK1 to menaquinones and VK recycling. However, in the course of CKD with hyperparathyroidism, the intensified osteoblastogenesis causes the generation of immature osteoblasts with impaired mineralization. The particular clinical significance seems to have a finding that serum osteocalcin and Glu-OC, commonly used biomarkers of VK deficiency, could be inappropriate in CKD conditions, whereas Gla-OC synthesized in bone appears to have an adverse impact on bone mineral status in this model.

Fatty Acid-Binding Protein 7 (FABP-7), Glutamic Acid and Neurofilament Light Chain (NFL) as Potential Markers of Neurodegenerative Disorders in Psoriatic Patients-A Pilot Study.

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.

The Potential Role of Serum Tau Protein (MAPT), Neuronal Cell Adhesion Molecule (NrCAM) and Neprilysin (NEP) in Neurodegenerative Disorders Development in Psoriasis-Preliminary Results.

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. Sixty 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 < 0.05). There was no association between these markers and psoriasis severity, BMI or disease duration. After the treatment the concentration of NrCAM and NEP significantly increased and MAPT decreased (p < 0.001, p < 0.05, p < 0.01, respectively). Methotrexate had significant influence on the concentrations of all markers, hence it seems to have neuroprotective properties. Psoriasis severity and duration do not seem to affect the risk of neurodegenerative process. Our results suggest that NDs could be considered as another comorbidity of psoriasis and that further research are needed in order to establish their definite association.

Vitamin K and D Supplementation and Bone Health in Chronic Kidney Disease-Apart or Together?

Vitamin K (VK) and vitamin D (VD) deficiency/insufficiency is a common feature of chronic kidney disease (CKD), leading to impaired bone quality and a higher risk of fractures. CKD patients, with disturbances in VK and VD metabolism, do not have sufficient levels of these vitamins for maintaining normal bone formation and mineralization. So far, there has been no consensus on what serum VK and VD levels can be considered sufficient in this particular population. Moreover, there are no clear guidelines how supplementation of these vitamins should be carried out in the course of CKD. Based on the existing results of preclinical studies and clinical evidence, this review intends to discuss the effect of VK and VD on bone remodeling in CKD. Although the mechanisms of action and the effects of these vitamins on bone are distinct, we try to find evidence for synergy between them in relation to bone metabolism, to answer the question of whether combined supplementation of VK and VD will be more beneficial for bone health in the CKD population than administering each of these vitamins separately.

Preclinical Toxicity and Safety of MM-129-First-in-Class BTK/PD-L1 Inhibitor as a Potential Candidate against Colon Cancer.

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.

MM-129 as a Novel Inhibitor Targeting PI3K/AKT/mTOR and PD-L1 in Colorectal Cancer.

BACKGROUND AND AIMS: The purpose of the present study was to examine the pharmacodynamics features of MM-129 (1,2,4-triazine derivative) as a novel promising drug candidate against colon cancer. METHODS: MM-129 was assessed for antitumor activity through an in vivo study on Cby.Cg-Foxn1nu/cmdb mice. The mechanistic studies investigated cellular affinity of a new 1,2,4-triazine derivative by measuring levels of intracellular/extracellular signal molecules participating in tumorigenesis. RESULTS: The results revealed that MM-129 significantly reduced tumor growth in mice challenged with DLD-1 and HT-29 cells. It exerted the ability to inhibit intracellular molecules promoting tumorigenesis and inducing cell cycle arrest, like Akt, mTOR, and CDK2. Simultaneously, it was able to downregulate PD-L1 expression, which involves immunological self-tolerance. Combined administration of MM-129 and 5-fluorouracil (5-FU) additionally amplified these effects, which were manifest as an increase population of cells in the G0/G1 phase. CONCLUSIONS: A novel 1,2,4-triazine derivative with a dual mechanism of antitumor activity-MM-129, may act as a chemosensitizer, overcoming chemoresistance against 5-FU, the first-line agent in the chemotherapy of colon cancer.

Intracellular mechanisms of tumor cells' immunoresistance.

One of the main mechanisms for avoiding immune response by cancer cells is mediated by inducing an immunosuppressive environment in the tumor following activation of immune checkpoints, i.e. PD-1 or CTLA-4 receptor inhibitors on T lymphocytes. Interaction inhibition between PD-1 or CTLA-4 and their ligands (PD-L1, CD80, and CD85) leads to unblocking of the T-lymphocyte function, and thus destroys cancer cells. Certain intracellular signaling pathways are also involved in the development of tumor cell immunoresistance. Immunosuppressive pathways' activation blocking may increase the immunological anti-tumor control.

Astrogliosis in an Experimental Model of Hypovitaminosis B12: A Cellular Basis of Neurological Disorders due to Cobalamin Deficiency.

Cobalamin deficiency affects human physiology with sequelae ranging from mild fatigue to severe neuropsychiatric abnormalities. The cellular and molecular aspects of the nervous system disorders associated with hypovitaminosis B12 remain largely unknown. Growing evidence indicates that astrogliosis is an underlying component of a wide range of neuropathologies. Previously, we developed an in vitro model of cobalamin deficiency in normal human astrocytes (NHA) by culturing the cells with c-lactam of hydroxycobalamin (c-lactam OH-Cbl). We revealed a non-apoptotic activation of caspases (3/7, 8, 9) in cobalamin-deficient NHA, which may suggest astrogliosis. The aim of the current study was to experimentally verify this hypothesis. We indicated an increase in the cellular expression of two astrogliosis markers: glial fibrillary acidic protein and vimentin in cobalamin-deficient NHA using Western blot analysis and immunocytochemistry with confocal laser scanning microscopy. In the next step of the study, we revealed c-lactam OH-Cbl as a potential non-toxic vitamin B12 antagonist in an in vivo model using zebrafish embryos. We believe that the presented results will contribute to a better understanding of the cellular mechanism underlying neurologic pathology due to cobalamin deficiency and will serve as a foundation for further studies.