Human Embryonic and Rat Adult Stem Cells with Primitive Endoderm-Like Phenotype Can Be Fated to Definitive Endoderm, and Finally Hepatocyte-Like Cells

Stem cell-derived hepatocytes may be an alternative cell source to treat liver diseases or to be used for pharmacological purposes. We developed a protocol that mimics mammalian liver development, to differentiate cells with pluripotent characteristics to hepatocyte-like cells. The protocol supports the stepwise differentiation of human embryonic stem cells (ESC) to cells with characteristics of primitive streak (PS)/mesendoderm (ME)/definitive endoderm (DE), hepatoblasts, and finally cells with phenotypic and functional characteristics of hepatocytes. Remarkably, the same protocol can also differentiate rat multipotent adult progenitor cells (rMAPCs) to hepatocyte-like cells, even though rMAPC are isolated clonally from cultured rat bone marrow (BM) and have characteristics of primitive endoderm cells. A fraction of rMAPCs can be fated to cells expressing genes consistent with a PS/ME/DE phenotype, preceding the acquisition of phenotypic and functional characteristics of hepatocytes. Although the hepatocyte-like progeny derived from both cell types is mixed, between 10–20% of cells are developmentally consistent with late fetal hepatocytes that have attained synthetic, storage and detoxifying functions near those of adult hepatocytes. This differentiation protocol will be useful for generating hepatocyte-like cells from rodent and human stem cells, and to gain insight into the early stages of liver development

Assessment of the Kinetics of Local Plastic Deformation of Zr-2.5%Nb CANDU Pressure Tube Material

Constant-load pyramidal indentation creep tests and high precision micro-indentation strain rate change tests were performed to assess the effect of indentation depth, irradiation damage and temperature on the mechanical anisotropy and local plastic deformation parameters of the Zr-2.5%Nb CANDU pressure tube material. Polished samples aligned normal to the transverse (TN), axial (AN) and radial (RN) directions of the pressure tube were irradiated with 8.5 MeV Zr+ ions to simulate the effect of neutron irradiation. Constant-load pyramidal indentation creep tests performed at 25ºC show that the average indentation stress increases with decreasing indentation depth and increasing levels of irradiation. The ratio of indentation stresses on the TN plane relative to that on the AN and RN planes was 1.3 and 1.2 respectively before irradiation which reduced to 1.04 and 1.08 respectively after irradiation indicating a decrease in anisotropy as a result of irradiation hardening. The apparent activation energy of the obstacles that limit the rate of dislocation glide during indentation creep at 25ºC does not change with indentation depth and direction but increases with increasing levels of irradiation damage. Samples irradiated at 300°C with 8.5 MeV Zr+ ions show similar changes in indentation stress, anisotropy and activation energy with increasing levels of irradiation. However the values are lower than those exposed to Zr+ irradiation at 25°C indicating the effect of concurrent thermal annealing on the accumulation of irradiation damage. Micro-indentation creep tests performed on the non-irradiated samples over the temperature range from 25 to 400ºC show that the ratio of indentation stresses in the transverse direction relative to that in the radial and axial directions decreased with increasing temperature. The apparent activation energy increases with increasing temperature and is independent of indentation direction. Micro-indentation strain rate change tests show that the inverse apparent activation area of the deformation process followed a linear, Cottrell Stokes type, dependence upon the applied stress. The increase in the apparent activation work indicates that the irradiation induced damage act as strong obstacles to dislocation glide and thus increase both the magnitude and the strain rate sensitivity of the yield stress of the Zr-2.5%Nb alloy at 25ºC

Lack of Myostatin reduces MyoD induced myogenic potential of primary muscle fibroblasts

Conversion of skin fibroblasts into myoblasts by transducing the cells with myogenic master regulator MyoD has been in practice for more thantwo decades. The purpose of such conversion is due to scarcity of muscle biopsies during muscle wasting, hence conversion of fibroblasts tomyogenic lineage from various genetic backgrounds offers a great alternative for cell therapies. Here, we have investigated if eliminatingMyostatin, a potent negative regulator of myogenesis, could improve the myogenic conversion of fibroblasts. In the present study, we haveisolated primary muscle fibroblasts from the skeletal muscles of wild-type (WT) and myostatin null (Mstn -/-) mice and transduced the musclefibroblasts with MyoD using adenoviral, lentiviral transduction, and electroporation methods. In contrast to what we predicted, it is only in WTmuscle fibroblasts we detected significant ectopic expression of MyoD, and myogenic conversion. Muscle fibroblasts from Mstn -/- genotypefailed to take up as much MyoD using the three methods and, therefore, failed to form myotubes. The aforesaid condition of greater MyoDuptake by WT muscle fibroblasts was attributed to the presence of adenoviral receptors, which facilitated adenoviral transduction. However, in Mstn -/- fibroblasts we detected negligible levels of adenovirus receptors. Moreover, we also detected significantly higher levels of MyoDantagonists, c-Fos, c-Jun, and cyclin D1 in Mstn -/- muscle fibroblasts. Taken together, our results demonstrate that lack of myostatin reducesmyogenic potential of muscle fibroblasts by inhibiting MyoD function

Lack of Myostatin reduces MyoD induced myogenic potential of primary muscle fibroblasts

Conversion of skin fibroblasts into myoblasts by transducing the cells with myogenic master regulator MyoD has been in practice for more thantwo decades. The purpose of such conversion is due to scarcity of muscle biopsies during muscle wasting, hence conversion of fibroblasts tomyogenic lineage from various genetic backgrounds offers a great alternative for cell therapies. Here, we have investigated if eliminatingMyostatin, a potent negative regulator of myogenesis, could improve the myogenic conversion of fibroblasts. In the present study, we haveisolated primary muscle fibroblasts from the skeletal muscles of wild-type (WT) and myostatin null (Mstn -/-) mice and transduced the musclefibroblasts with MyoD using adenoviral, lentiviral transduction, and electroporation methods. In contrast to what we predicted, it is only in WTmuscle fibroblasts we detected significant ectopic expression of MyoD, and myogenic conversion. Muscle fibroblasts from Mstn -/- genotypefailed to take up as much MyoD using the three methods and, therefore, failed to form myotubes. The aforesaid condition of greater MyoDuptake by WT muscle fibroblasts was attributed to the presence of adenoviral receptors, which facilitated adenoviral transduction. However, in Mstn -/- fibroblasts we detected negligible levels of adenovirus receptors. Moreover, we also detected significantly higher levels of MyoDantagonists, c-Fos, c-Jun, and cyclin D1 in Mstn -/- muscle fibroblasts. Taken together, our results demonstrate that lack of myostatin reducesmyogenic potential of muscle fibroblasts by inhibiting MyoD function

Differential role of MAP kinase isoforms in malachite green transformed Syrian hamster embryo fibroblasts in culture

693-698Malachite green (MG) induces DNA damage and malignant transformation of Syrian hamster embryo (SHE) cells in primary culture. In the present study, we have studied the role of all the three isoforms of mitogen activated protein (MAP) kinases i.e. ERK (extracellular regulated kinase), JNK (JUN- N- terminal kinase) and p38 kinase during transformation of SHE cells by MG. The results showed that transformed cells were associated with a decreased expression of phosphoactive ERK and JNK and increased expression of p38 kinase as evident from the Western blot, immunofluorescence and flow cytometry studies. Also, a persistent nuclear localization of p38 kinase was observed in the transformed cells. The present study indicated that p38 kinase was present at higher levels and seemed to be associated with transformation, which suggested that inhibitors of p38 kinase could serve in general as potential agents for selective cancer therapy

Improvement of Wear Performance of Nano-Multilayer PVD Coatings under Dry Hard End Milling Conditions Based on Their Architectural Development

The TiAlCrSiYN-based family of PVD (physical vapor deposition) hard coatings was specially designed for extreme conditions involving the dry ultra-performance machining of hardened tool steels. However, there is a strong potential for further advances in the wear performance of the coatings through improvements in their architecture. A few different coating architectures (monolayer, multilayer, bi-multilayer, bi-multilayer with increased number of alternating nano-layers) were studied in relation to cutting-tool life. Comprehensive characterization of the structure and properties of the coatings has been performed using XRD, SEM, TEM, micro-mechanical studies and tool-life evaluation. The wear performance was then related to the ability of the coating layer to exhibit minimal surface damage under operation, which is directly associated with the various micro-mechanical characteristics (such as hardness, elastic modulus and related characteristics; nano-impact; scratch test-based characteristics). The results presented exhibited that a substantial increase in tool life as well as improvement of the mechanical properties could be achieved through the architectural development of the coatings

Sodium fluoride induces skeletal muscle atrophy via changes in mitochondrial and sarcomeric proteomes.

Sodium Fluoride (NaF) can change the expression of skeletal muscle proteins. Since skeletal muscle is rich in mitochondrial and contractile (sarcomeric) proteins, these proteins are sensitive to the effects of NaF, and the changes are dose-and time-dependent. In the current study, we have analysed the effect of high concentrations of NaF (80ppm) on mouse skeletal muscle at two different time points, i.e., 15 days and 60 days. At the end of the experimental time, the animals were sacrificed, skeletal muscles were isolated, and proteins were extracted and subjected to bioinformatic (Mass Spectrometric) analysis. The results were analysed based on changes in different mitochondrial complexes, contractile (sarcomeric) proteins, 26S proteasome, and ubiquitin-proteasome pathway. The results showed that the mitochondrial proteins of complex I, II, III, IV and V were differentially regulated in the groups treated with 80ppm of NaF for 15 days and 60 days. The network analysis indicated more changes in mitochondrial proteins in the group treated with the higher dose for 15 days rather than 60 days. Furthermore, differential expression of (sarcomeric) proteins, downregulation of 26S proteasome subunits, and differential expression in proteins related to the ubiquitin-proteasome pathway lead to muscle atrophy. The differential expression might be due to the adaptative mechanism to counteract the deleterious effects of NaF on energy metabolism. Data are available via ProteomeXchange with identifier PXD035014

G2/M-Phase-Inhibitory Mitochondrial-Depolarizing Re(I)/Ru(II)/Ir(III)-2,2′-Bipyrimidine-Based Heterobimetallic Luminescent Complexes: An Assessment of In Vitro Antiproliferative Activity and Bioimaging for Targeted Therapy toward Human TNBC Cells

Triple-negative breast cancer (TNBC) is an extremely vicious subtype of human breast cancer having the worst prognosis along with strong invasive and metastatic competency. Hence, it can easily invade into blood vessels, and presently, no targeted therapeutic approach is available to annihilate this type of cancer. Metal complexes have successfully stepped into the anticancer research and are now being applauded due to their anticancer potency after the discovery of cisplatin. Many of these metal complexes are also well recognized for their activity toward breast cancer. As the TNBC is a very dangerous subtype and has long been a challenging ailment to treat, we have intended to develop a few brand new mixed metallic Ru(II)/Ir(III)/Re(I)-2,2′-bipyrimidine complexes [L′Re2], [L′RuRe], and [L′IrRe] to abate the unbridled proliferation of TNBC cells. The potency of the complexes against TNBC cells has been justified using MDA-MB-468 TNBC cell lines where complex [L′IrRe] has displayed significant potency among all the three complexes with an IC50 value of 24.12 μM. The complex [L′IrRe] has been competent to cause apoptosis of TNBC cells through inhibition of the G2/M phase in the cell cycle in association with a profuse amount of ROS generation and mitochondrial depolarization