Biological effects of molybdenum(IV) sulfide nanoparticles and microparticles in the rat after repeated intratracheal administration.

In this study, molybdenum(IV) sulfide (MoS2 ) nanoparticles (97 ± 32 nm) and microparticles (1.92 ± 0.64 µm) stabilized with poly (vinylpolypyrrolidone) (PVP) were administered intratracheally to male and female rats (dose of 1.5 or 5 mg/kg bw), every 14 days for 90 days (seven administrations in total). Blood parameters were assessed during and at the end of the study (hematology, biochemistry including glucose, albumins, uric acid, urea, high density lipoprotein HDL, total cholesterol, triglycerides, aspartate transaminase, and alanine transaminase ALT). Bronchoalveolar lavage fluid (BALF) analyses included cell viability, biochemistry (total protein concentration, lactate dehydrogenase, and glutathione peroxidase activity), and cytokine levels (tumor necrosis factor α, TNF-α, macrophage inflammatory protein 2-alpha, MIP-2, and cytokine-induced neutrophil chemoattractant-2, CINC-2). Tissues were subjected to routine histopathological and electron microscopy (STEM) examinations. No overt signs of chronic toxicity were observed. Differential cell counts in BALF revealed no significant differences between the animal groups. An increase in MIP-2 and a decrease in TNF-α were observed in BALF in the exposed males. The histopathological changes in the lung evaluated according to a developed classification system (based on severity of inflammation, range 0-4, with 4 indicating the most severe changes) showed average histopathological score of 1.33 for animals exposed to nanoparticles and microparticles at the lower dose, 1.72 after exposure to nanoparticles at the higher dose, and 2.83 for animals exposed to microparticles at the higher dose. In summary, it was shown that nanosized and microsized MoS2 can trigger dose-dependent inflammatory reactions in the lungs of rats after multiple intratracheal instillation irrespective of the animal sex. Some evidence indicates a higher lung pro-inflammatory potential of the microform.

Comparative analysis of biological effects of molybdenum(IV) sulfide in the form of nano- and microparticles on human hepatoma HepG2 cells grown in 2D and 3D models.

Significance of MoS2 nanoparticles as a lubricant or drug carriers indicates the need to assess their safety. In the study we analyzed the effects of MoS2 nano- and microparticles and their internalization in vitro, using 2D and 3D culture models of human hepatoma HepG2 cell line. MoS2 micro- and nanoparticles were characterized with high resolution electron microscopy (HR-SEM), X-ray diffraction (XRD) and Energy Dispersive X-Ray Spectroscopy (EDS). The cells were exposed to a range of concentrations of the nano-and microparticles suspensions (maximum of 250 µg/mL) for 72 h. Cell viability was assessed using WST-1 reduction test and LDH release assay. Particle internalization was analyzed using scanning transmission electron microscopy (STEM). The nanoparticles were internalized into the 2D and 3D cultured cells, in spheroids more efficiently into the outer layer. For microparticles mainly particles of less than 1 µm in diameter underwent internalization. This process, however, did not affect cell viability as measured with the WST-1 and LDH assays. STEM observation showed well preserved integrity of the cell membrane and no apparent cytotoxic effect. Although the particles seemed to be safely sequestered in vacuoles or the cytoplasm, their fate and eventual biological effects are not certain and deserve further studies.

Assessment of acute toxicological effects of molybdenum(IV) disulfide nano- and microparticles after single intratracheal administration in rats.

Despite growing applications of molybdenum(IV) sulfide (MoS2) nano- and microparticles in their capacity as lubricants, data available on their safety are scarce. In this study the effect of MoS2 nano- and microparticles after single intratracheal instillation in rats has been analyzed. MoS2 suspensions were administered at the dose of 1.5 or 5 mg MoS2/kg body weight. The analysis after 24 h and 7 days included: blood biochemical parameters, hematological parameters, bronchoalveolar lavage fluid (BALF) parameters with selected cytokines, a comet assay and histopathological examination. In the BALF cells isolated from animals exposed to both forms, numerous macrophages loaded with particles were observed. The hematological and biochemical parameters analyzed 24 h or 7 days after the exposure to both forms did not show any biologically meaningful changes. Comet assay results showed no genotoxic effect. The histopathological analysis of the lungs revealed inflammatory changes in the respiratory system of the treated animals, slightly stronger for the microsized form. The deposits of particles observed in the lung tissue up to 7 days after the instillation indicate their easy penetration through the epithelium and prolonged clearance. Concluding, no meaningful acute systemic effects were observed, however some pathological changes were noted in the lung tissue.

Cytotoxic effects in transformed and non-transformed human breast cell lines after exposure to silver nanoparticles in combination with selected aluminium compounds, parabens or phthalates.

This study was undertaken to assess cytotoxic effects of selected aluminium compounds, parabens and phthalates in combination with silver nanoparticles (AgNP, 15 and 45 nm by STEM, Ag15 and Ag45, respectively) on cell lines of the human breast epithelium, normal (MCF-10A) and transformed (MDA-MB-231 and MCF-7). Combination indices were the most spectacular at effective concentrations (ED) inducing 25 % decrease in viability for the combinations of Ag15 with AlCl3 for MDA-MB-231 cells or aluminium zirconium tetrachlorohydrex Gly (AlZr) for MCF-10A and MCF-7 cells, where rather strong antagonism was revealed. As the ED values increased, those effects were enhanced (e.g. Ag15+AlCl3 for MDA-MB-231) or reversed into synergism (e.g. Ag15+AlZr for MCF-7). Another strong effect was observed for aluminium chloride hydroxide, which increasing ED, induced synergistic effect with both Ag15 and Ag45 on MCF-10A cells. Another interesting synergistic effect was observed for DBPh, but only in combination with Ag45 on MCF-10A and MCF-7. The results on cytotoxicity, cell cycle and oxidative stress induction indicate complex response of the cell lines to combined treatment with silver nanoparticles and the chemicals, which were influenced by diverse factors, such as physico-chemical characteristics of AgNP, method of their synthesis, concentrations used, and finally cell type.

Mayer-Rokitansky-Küster-Hauser syndrome - case studies, methods of treatment and the future prospects of human uterus transplantation.

OBJECTIVE: We aimed to present patients with the Mayer-Rokitansky-Küster-Hauser syndrome (MRKH) coming from one center and presenting all the possibilities of its treatment, at the forefront with the uterine transplantation. PATIENTS AND METHODS: The presented work is an example of different types of MRKH syndrome diagnosed in 25 women who were diagnosed in the Department of Gynecological Endocrinology due to the primary amenorrhea from 01/2001 to 06/2018. RESULTS: Patients suffering from MRKH syndrome are capable of having genetic offspring but are unable to give birth to their own child, due to an absence of the uterus, blindly terminated vagina, and normal ovaries. Patients suffering from this syndrome have the opportunity to receive treatment in accordance with their current needs. However, there are many medical, technical, and ethical limitations in achieving the most important therapeutic target: uterine transplantation and childbirth. CONCLUSIONS: Until a few years ago, patients with an absolute uterine factor of infertility, including women with MRKH syndrome, had a real choice of only two equally controversial options giving a chance for motherhood - surrogacy and adoption. However, modern transplantation has shown that a third option - a uterine transplant - exists and is available.

The effect of inhibitors of phosphatidylinositol 3-kinase-related kinases on dibenzo[def,p]chrysene genotoxicity measured by γH2AX levels and neutral comet assay in HepG2 human hepatocellular cancer cells.

In the study the modulating effect of inhibition of phosphatidylinositol 3-kinase-related kinases (PIKK): ATM (Ataxia Telangiectasia Mutated), ATR (Ataxia Telangiectasia and Rad3 Related) and DNA-PK (DNA-dependent protein kinase) on genotoxicity of dibenzo[def,p]chrysene (DBC) in HepG2 human hepatocellular cancer cells was investigated. The cytotoxicity of DBC was determined, also in combination with PIKK inhibitors, using the MTT reduction assay. The high cytotoxicity of DBC was observed after 72 h incubation (IC50 = 0.06 µM). The PIKK inhibitors applied at non-cytotoxic concentrations: caffeine (1 mM) and KU55933 (2.5 µM) had no significant influence on the DBC cytotoxicity, however NU7026 (5 µM) caused significant increase in the cell viability by about 25%. The combinations of the inhibitors (double or triple) where NU7026 was present also caused increase in the cell viability (i.e. cytoprotective effect) compared to the effect of DBC. The level of damage to the genetic material (DNA double strand breaks, DSB) was assessed by measuring levels of phosphorylated form of H2A histone (γH2AX) and neutral comet assay. DBC induced DSB in a concentration and time-dependent manner. NU7026 considerably reduced the level of DSB level measured by γH2AX and comet assay. The obtained results confirm that DBC is cytotoxic and causes damage to the genetic material including DSB. The DNA-PK inhibitor NU7026 increases cell viability after exposure to DBC and reduces DNA damage, what indicates an important role of the sensor kinase in mediating the effect.

Micronuclei frequency in peripheral blood lymphocytes and levels of anti-p53 autoantibodies in serum of residents of Kowary city regions (Poland) with elevated indoor concentrations of radon.

INTRODUCTION: Ninety four residents of Kowary city (Poland) have been investigated for environmental radon exposure that ranged from 0.24 WLM to 9.6 WLM (activity concentration range: 35-2700 Bq/m3). Kowary was chosen because of uranium mineralisation in its close vicinity. METHOD: Whole population studied was divided into two groups: exposed to low radon activity concentrations resulting in the exposure of ≤0.55 WLM (value corresponding to the exposure to 100 Bq/m3 during whole year), and exposed to high radon activity concentration (>0.55 WLM). In the two groups two selected biomarkers in blood were assessed: the cytokinesis-block micronucleus assay (CBMN) on peripheral blood lymphocytes (PBL), and the levels of anti-p53 antibodies in serum measured because some data indicate increased expression of the antibodies in individuals after exposure to DNA damaging agents including radon. The potential confounding factors known to influence micronuclei (MN) frequency were also measured in serum: vitamin B12, folic acid, as well as total calcium. RESULTS: In the present study no significant correlation was found between MN frequency in PBL and radon exposure. Among all persons investigated only 11 had detectable levels of the anti-p53 antibodies, whereas only 3 persons had positive result. Therefore, the group was too small to perform any meaningful statistical analysis and to conclude on any association. Cigarette smoking did not significantly influence the number of MN. There was a significant positive correlation observed between MN frequency and age, as well as higher MN frequency was detected in women. CONCLUSION: The problem of the radon exposure is still unresolved and needs further studies on bigger human cohorts in order to search for more sensitive biomarkers.

The correlation between the concentration of hepcidin in serum and the occurrence of insulin resistance and hyperandrogenemia in women with polycystic ovary syndrome.

OBJECTIVE: Scarce clinical and experimental studies suggest that hepcidin can be a protein participating in the development of metabolic disorders, while its synthesis and concentration in the circulation outside of the iron metabolism parameters can be influenced by hormones. The aim of the present study was to determine the correlation between the concentration of hepcidin in serum and the occurrence of insulin resistance and hyperandrogenemia in women with PCOS. PATIENTS AND METHODS: Five groups of women with PCOS were divided based on: correct body mass (17 without hyperandrogenemia and insulin resistance - G1; 17 with hyperandrogenemia and without insulin resistance - G2; 11 without hyperandrogenemia and with insulin resistance - G3; 10 with hyperandrogenemia and insulin resistance - G4), metabolic and hormonal parameters and selected markers of iron metabolism. RESULTS: Serum glucose levels were significantly higher in the group G3 than G1 and in the group G4 than G1 and G2. Serum insulin levels and HOMA-IR values were significantly higher in the groups G3 and G4 than G1 and G2. Serum androstenedione levels were significantly higher in the group G2 than G1 and G3 than G2. Serum transferrin levels were significantly lower in the group G1 than in the reaming study groups. CONCLUSIONS: It has been demonstrated that insulin resistance and hyperandrogenemia appear to be the factors decreasing the concentration of transferrin circulation, but not the remaining parameters of the iron metabolism in the studied women. No relationship between the concentration of hepcidin circulation and other studied parameters of the iron metabolism and the parameters of the carbohydrate metabolism was discovered. Androstenedione can stimulate hepcidin synthesis in women with PCOS with correct body mass.

Hormonal and metabolic aspects of acne vulgaris in women with polycystic ovary syndrome.

OBJECTIVE: Acne vulgaris in women can indicate a systemic disease, such as polycystic ovary syndrome (PCOS), which is associated with hormonal and metabolic disorders. The aim of this study was to investigate the influence of hormonal and metabolic disorders on acne vulgaris in women with PCOS. PATIENTS AND METHODS: The study included 110 women with PCOS. Women were divided according to their androstenedione concentration: within reference range (n=66) or higher (n=44). All patients were between 17-36 years old. Acne was graded according to the US FDA scale for a five-category global system (acne global severity scale). Hirsutism was defined using a modified Ferriman-Gallwey method. Fasting plasma glucose, insulin, luteinizing hormone, follicle-stimulating hormone, 17α-hydroxyprogesterone, 17-beta-estradiol, sex hormone-binding globulin and androgen (androstenedione, total testosterone, free testosterone, dehydroepiandrosterone sulfate) were assessed, as were prolactin and cortisol concentrations. Thyrotropin and free thyroxine concentrations were also measured. The free androgen index (FAI) and homeostatic model assessment-insulin resistance (HOMA-IR) index were calculated. RESULTS: The average age and rating on the hirsutism scale were similar in both analyzed groups. A higher percentage of severe acne was observed in the group of women with an androstenedione concentration within reference range than in the group with the higher concentration. Meanwhile, the severity of acne in the group of PCOS women with the higher androstenedione concentration was correlated with higher concentrations of total testosterone, free testosterone, dehydroepiandrosterone sulfate, and cortisol. Increased glucose concentration was also proportional to the severity of acne. We did not observe a statistically significant correlation between the severity of acne and the androstenedione concentration. In the group of PCOS women as a whole, the severity of acne was correlated only with higher dehydroepiandrosterone sulfate concentration; other androgens did not affect the severity. CONCLUSIONS: The acne global severity scale in PCOS women is associated with higher concentrations of total testosterone, free testosterone, dehydroepiandrosterone sulfate, and FAI value. Higher concentrations of androstenedione did not affect acne severity.

Effects of nitrogen-deficiency on efficiency of light-harvesting apparatus in radish.

Nitrogen starvation has been stated to reduce chlorophyll a and accessory pigments, decrease photosynthetic efficiency, as well as modify chloroplast thylakoid membranes. However, the impact of N-deficiency on light-dependent reactions of photosynthesis has not been well understood. In this study, efficiency and structure of light-harvesting complex under N-deficiency conditions were investigated in two radish cultivars (Raphanus sativus var. sativus 'Fluo HF1' and 'Suntella F1'). Light-dependent reactions of photosynthesis were investigated by measuring in vivo chlorophyll a prompt fluorescence signal. Acquired data were utilised in two ways: by plotting fast induction curves and calculating OJIP-test biophysical parameters. Detailed analysis of difference curves as well as OJIP-test results showed that major disturbances were associated with photosystem II and its subunits, including decoupling of light-harvesting complexes, dysfunction of oxygen-evolving complex, and reaction centres inactivation. The maximum quantum yield of photosystem II primary photochemistry was severely restricted, causing an inhibition in electron transport through successive protein complexes in the thylakoid membrane. Structural changes were demonstrated by recording images using Transmission Electron Microscopy (TEM). TEM investigations showed intensive starch accumulation under N-deficiency. Rare thylakoid stacks distributed in tiny layers of stroma around grains and chloroplast periphery were observed in cells of N-deficient plants. The application of principal component analysis (PCA) on OJIP-test results allowed characterizing the dynamics of stress response and separating parameters according to their influence on plants stress response. 'Suntella F1' genotype was found to be more sensitive to nitrogen deficiency as compared to 'Fluo HF1' genotype.

Thyroid disorders in polycystic ovary syndrome.

OBJECTIVE: Thyroid disorders, especially Hashimoto's thyroiditis (HT), are observed significantly more often in patients with polycystic ovary syndrome (PCOS) than in the general population - approximately 27% and 8%, respectively. This is extremely important in young women, because both disorders are connected with fertility problems. As HT and PCOS occur together, fertility problems may become a serious clinical issue in these patients. MATERIALS AND METHODS: A systematic literature review in PubMed of PCOS- and HT-related articles in English, published until December 2015 was conducted. RESULTS: The reasons for joint prevalence still remain unclear. Genetic and autoimmune backgrounds are recognized to be possible common etiological factors. Three genetic polymorphisms have been described to play a role in PCOS as well as in HT. They are polymorphism of the gene for fibrillin 3 (FBN3) regulating the activity of transforming growth factor-b (TGF-b) and regulatory T cell levels, gonadotropin-releasing hormone receptor (GnRHR) polymorphism and CYP1B1 polymorphism standing for estradiol hydroxylation. High estrogen-to-progesterone ratios owing to anovulatory cycles, as well as high estrogen levels during prenatal life, disrupt development of the thymus and its function in maintaining immune tolerance, and are suspected to enhance autoimmune response in PCOS. Vitamin D deficiency could be also involved in the pathogenesis of HT and PCOS. CONCLUSIONS: The above-mentioned common etiological factors associated with fertility problems in HT and PCOS require further research.

Tumor necrosis factor-α alters integrins and metalloprotease ADAM12 levels and signaling in differentiating myoblasts.

The extracellular matrix (ECM) is important in the regulation of myogenesis. We hypothesized that tumor necrosis factor-α (TNF-α) modifies ECM during differentiation of mouse C2C12 myoblasts. Exogenous TNF-α (1 ng/ml) stimulated myoblast fusion on the 3rd day (by 160% vs control) but not on the 5th day of myogenesis. The level of integrin α5 was significantly augmented by TNF-α during 5 day-differentiation; however, integrin ß1 was higher than control only on the 3rd day of cytokine treatment. Both the abundance of integrin α5 bound to actin and the level of integrin ß1 complexed with integrin α5 increased in the presence of TNF-α, especially on the 3rd day of differentiation. Similarly, the stimulatory effects of TNF-α on integrin α3, metalloprotease ADAM12 and kinases related to integrins, FAK and ILK, were limited to the 3rd day of differentiation. We concluded that TNF-α-induced changes in ECM components in differentiating myogenic cells, i.e. i) increased expression of integrin α5, ß1, α3, and metalloprotease ADAM12, ii) enhanced formation of α5ß1 integrin receptors and interaction of integrin α5-cytoskeleton, and iii) increased expression of kinases associated with integrin signaling, FAK and ILK, were temporarily associated with the onset of myocyte fusion.

The effect of palmitate supplementation on gene expression profile in proliferating myoblasts.

High-fat diet, exposure to saturated fatty acids, or the presence of adipocytes in myoblast microenvironment affects skeletal muscle growth and function. The aim of the present study was to investigate the effect of palmitate supplementation on transcriptomic profile of mouse C2C12 myoblasts. Global gene expression was evaluated using whole mouse genome oligonucleotide microarrays, and the results were validated through qPCR. A total of 4047 genes were identified as differentially expressed, including 3492 downregulated and 555 upregulated genes, during a 48-h exposure to palmitate (0.1 mmol/l). Functional classification showed the involvement of these genes in several processes which regulate cell growth. In conclusion, the addition of palmitate modifies the expression of genes associated with (1) myoblast responsiveness to hormones and growth factors, (2) cytokine and growth factor expression, and (3) regulation of cell-cell and cell-matrix communication. Such alterations can affect myoblast growth and differentiation; however, further studies in this field are required.

Olfactory training induces changes in regional functional connectivity in patients with long-term smell loss.

Recently, olfactory training has been introduced as a promising treatment for patients with olfactory dysfunction. However, less is known about the neuronal basis and the influence on functional networks of this training. Thus, we aimed to investigate the neuroplasticity of chemosensory perception through an olfactory training program in patients with smell loss. The experimental setup included functional MRI (fMRI) experiments with three different types of chemosensory stimuli. Ten anosmic patients (7f, 3m) and 14 healthy controls (7f, 7m) underwent the same testing sessions. After a 12-week olfactory training period, seven patients (4f, 3m) were invited for follow-up testing using the same fMRI protocol. Functional networks were identified using independent component analysis and were further examined in detail using functional connectivity analysis. We found that anosmic patients and healthy controls initially use the same three networks to process chemosensory input: the olfactory; the somatosensory; and the integrative network. Those networks did not differ between the two groups in their spatial extent, but in their functional connectivity. After the olfactory training, the sensitivity to detect odors significantly increased in the anosmic group, which was also manifested in modifications of functional connections in all three investigated networks. The results of this study indicate that an olfactory training program can reorganize functional networks, although, initially, no differences in the spatial distribution of neural activation were observed.

Metabolic modulators of the exercise response: doping control analysis of an agonist of the peroxisome proliferator-activated receptor δ (GW501516) and 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR).

In 2008, the team of Ronald Evans, a professor at the Salk Institute Gene Expression Laboratory, published an article about the effects of two metabolic modulators branded as GW501516 and AICAR on physical endurance of laboratory animals. Both substances, also called 'exercise pills' or 'exercise mimetics', showed the ability to cause multidirectional changes in muscle metabolism. In particular, they stimulated fatty acid oxidation and promoted muscle remodelling. These compounds were regarded as very promising drug candidates for the treatment of diseases such as obesity and type 2 diabetes. GW501516 and AICAR have received considerable attention in doping control due to assumed performance-enhancing properties and recent confiscations of illicitly distributed drugs containing AICAR. Therefore, the World Anti-Doping Agency added GW501516 and AICAR to the Prohibited List in 2009. This review covers the cellular and systemic effects of the metabolic modulators' administration with special emphasis on their role in exercise metabolism. It also presents the advancements in development of methodologies for the detection of their abuse by athletes.

The influence of high glucose and high insulin on mechanisms controlling cell cycle progression and arrest in mouse C2C12 myoblasts: the comparison with IGF-I effect.

BACKGROUND: Myogenesis is susceptible to the availability of nutrients and humoral factors and suboptimal fetal environments affect the number of myofibers and muscle mass. AIM: We examined the mechanisms regulating cell cycle progression and arrest in skeletal myoblasts. MATERIALS AND METHODS: Mouse C2C12 myoblasts were subjected to proliferation or induction of differentiation in the presence of high glucose and high insulin (HGHI glucose 15 mmol/l, insulin 50 nmol/l), and these effects were compared with the influence of anabolic factor for skeletal muscle, insulin-like growth factor-I (IGF-I 30 nmol/l). RESULTS: High glucose and high insulin, similarly to IGF-I, increased the intracellular level of cyclin A, cyclin B1 and cyclin D1 during myoblast proliferation. In HGHI-treated myoblasts, these cyclins were localized mostly in the nuclei, and the level of cdk4-bound cyclin D1 was augmented. HGHI significantly stimulated the expression of cyclin D3, total level of p21 and cdk-bound fraction of p21 in differentiating cells. The cellular level of MyoD was augmented by HGHI both in proliferating and differentiating myogenic cells. CONCLUSIONS: High glucose and insulin modify the mechanisms controlling cell cycle progression and the onset of myogenesis by: (1) increase of cyclin A, cyclin B1 and cyclin D1 in myoblast nuclei, and stimulation of cyclin D1-cdk4 binding; (2) increase in cyclin D3 and MyoD levels, and the p21-cdk4 complexes after induction of differentiation. Hyperglycemia/hyperinsulinemia during fetal or postnatal life could exert effects similar to IGF-I and can be, therefore, favourable for skeletal muscle growth and regeneration.

Interleukin-1beta stimulates early myogenesis of mouse C2C12 myoblasts: the impact on myogenic regulatory factors, extracellular matrix components, IGF binding proteins and protein kinases.

The purpose of the study was to examine the mechanisms important for early myogenesis in mouse C2C12 myogenic cells exposed to interleukin-1beta. Cyclin A and cyclin B1 were increased by interleukin-1beta (1 ng/ml), but the level of cyclin D1 and total DNA content was unaffected. Fusion index and the rate of protein synthesis was increased in the presence of IL-1beta, but these effects were limited to 3-day-treatment. IL-1beta increased the level of MyoD, myogenin and MHC on the 3rd day of differentiation, without altering the content of the active form of myostatin, as well as it augmented the level of fibronectin, integrin beta1 and full length 100 kDa form of ADAM12. IL-1beta caused a decrease in IGFBP-4 and IGFBP-6 levels and a marked increase in IGFBP-5. The phosphorylation of PKB and ERK1/2 and the cellular content of p38 were elevated by IL-1beta. We conclude that the myogenic effect of IL-1beta was limited to the onset of myoblast fusion and was associated with: i) increase in the level of myogenic transcription factors i.e. MyoD and myogenin expression, ii) modification of extracellular matrix assembly and signaling, manifested by an increase in fibronectin, integrin-beta1 and ADAM12 content, iii) drop in IGFBP-4 and IGFBP-6, and an increase in IGFBP-5, that could alter the local IGF-1 bioavailability, and iv) increase in phosphorylation of PKB and ERK1/2, and the expression of p38 kinase, leading to activation of intracellular pathways essential for myogenic differentiation.

High glucose-mediated alterations of mechanisms important in myogenesis of mouse C2C12 myoblasts.

We have examined the progression and regulation of myogenesis, cellular levels of IGFBP-4, -5, -6, and several extracellular matrix (ECM) proteins (fibronectin, integrin α5, ß1 subunits and a disintegrin metalloprotease ADAM12) in murine C2C12 myoblasts during 3-day differentiation under high glucose alone or combined with high insulin, factors characteristic for type 1 and 2 diabetes. High ambient glucose inhibited myogenesis of C2C12 myoblasts, an effect manifested by a twofold decrease in myoblast fusion, a drop in intracellular MyoD, myogenin and MHC levels, and increased cellular content of active myostatin isoform. Reduction in myogenesis by high glucose is accompanied by increase in cellular levels of IGFBP-4 and -6 and decrease in IGFBP-5. High glucose could modify ECM components assembly, by the increase in fibronectin levels and the decrease in metalloprotease ADAM12, without the effect on integrin α5 and ß1 subunits. In contrast, high glucose and high insulin activate myoblast differentiation, manifested by an increase in fusion index and myogenin, as well as a drop in myostatin levels. The presence of high insulin prevented high-glucose-dependent changes in IGFBPs and ECM proteins. The data indicate the potential mechanisms of the influence of extracellular environment associated with maternal diabetes and insulin resistance on foetal myogenesis.

Identification of Ppd-B1 alleles in common wheat cultivars by CAPS marker.

Photoperiod response is a major determinant of the duration of growth stages in common wheat. In common wheat, many genes play a role in determining flowering time, but the Ppd genes located on the homoeologous group 2 play a major role. Of these Ppd-B1 is located on the short arm of 2B. In 107 common wheat cultivars grown in Poland and neighboring countries, the identification of Ppd-B1 alleles using in-del analysis by using a CAPS markers was investigated. 87 cultivars were shown to carry dominant Ppd-B1 alleles. This shows that Ppd-B1 alleles is have been widely used in common wheat breeding programme in these countries. Recessive ppd-B1 alleles were found only in 20 cultivars (12 Polish, 5 former Soviet Union, 2 German, 1 Swedish).

Growth factor and cytokine interactions in myogenesis. Part I. The effect of TNF-alpha and IFN-gamma on IGF-I-dependent differentiation in mouse C2C12 myogenic cells.

UNLABELLED: The aim of this study was to examine the potential interactions of IGF-I with TNF-alpha and IFN-gamma with regard to regulation of the myogenesis and proliferative potential of mouse C2C12 myoblasts. The stimulation of myogenesis by IGF-I (30 nmol/l) was manifested by an enhanced myoblast fusion and expression of myosin heavy chain (MHC) during the first 3 days of differentiation. IGF-I-dependent fusion and MHC expression was reduced by TNF-alpha and IFN-gamma. Both cytokines prevented the stimulatory effect of IGF-I on MyoD expression with minor modification of the myogenin level. Both TNF-alpha and IFN-gamma activated the expression of cyclin A in myoblasts restimulated to proliferation; however, when used in combination with IGF-I these cytokines prevented the rise in cyclin A induced by growth factor. IN CONCLUSION: i) TNF-alpha and IFN-gamma reduce IGF-I-dependent myogenesis which was manifested by the reduction of myoblast fusion and MHC cellular levels, ii) Molecular mechanisms of inhibitory action of TNF-alpha and IFN-gamma on IGF-I-mediated differentiation involve a decrease in MyoD whereas myogenin level plays a minor role, iii) TNF-alpha and IFN-gamma increase the proliferative potential of myoblasts; however, they reduced the mitogenic effect of IGF-I, manifested by a decrease of IGF-I-stimulated cyclin A expression in myoblasts reinduced to proliferation. Interactions among IGF-I and proinflammatory cytokines are therefore important to establish a number of myoblasts and the onset of myogenesis during muscle regeneration.