Search results for "Cell Signaling"
showing 10 items of 228 documents
The Deep-Sea Natural Products, Biogenic Polyphosphate (Bio-PolyP) and Biogenic Silica (Bio-Silica), as Biomimetic Scaffolds for Bone Tissue Engineeri…
2013
Bone defects in human, caused by fractures/nonunions or trauma, gain increasing impact and have become a medical challenge in the present-day aging population. Frequently, those fractures require surgical intervention which ideally relies on autografts or suboptimally on allografts. Therefore, it is pressing and likewise challenging to develop bone substitution materials to heal bone defects. During the differentiation of osteoblasts from their mesenchymal progenitor/stem cells and of osteoclasts from their hemopoietic precursor cells, a lineage-specific release of growth factors and a trans-lineage homeostatic cross-talk via signaling molecules take place. Hence, the major hurdle is to fab…
Fusion of bone-marrow-derived cells with Purkinje neurons, cardiomyocytes and hepatocytes
2003
Recent studies have suggested that bone marrow cells possess a broad differentiation potential, being able to form new liver cells, cardiomyocytes and neurons1,2. Several groups have attributed this apparent plasticity to ‘transdifferentiation’3,4,5. Others, however, have suggested that cell fusion could explain these results6,7,8,9. Using a simple method based on Cre/lox recombination to detect cell fusion events, we demonstrate that bone-marrow-derived cells (BMDCs) fuse spontaneously with neural progenitors in vitro. Furthermore, bone marrow transplantation demonstrates that BMDCs fuse in vivo with hepatocytes in liver, Purkinje neurons in the brain and cardiac muscle in the heart, resul…
Targeting PCSK9 for therapeutic gains: Have we addressed all the concerns?
2016
Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) regulates the expression of low-density lipoprotein (LDL)-receptors, through reducing their recycling by binding to the receptor along with LDL and targeting it for lysosomal destruction. PCSK9 also enhances the degradation of very-low-density-lipoprotein receptor (VLDLR) and lipoprotein receptor-related protein 1 (LRP-1) in a LDL-receptor independent manner. This role in lipid homeostasis presents PCSK9 as an attractive target for the therapeutic management of familial hypercholesterolemia as well as other refractory dyslipidaemias. However, PCSK9 mediates multifarious functions independent of its role in lipid homeostasis, which can be…
Interleukin 23p19 inhibitors in chronic plaque psoriasis with focus on mirikizumab: A narrative review.
2020
Psoriasis, a T-cell mediated chronic dermatosis, has a complex etiopathogenesis. There has been extensive research into the aberrant immune response, which leads to the formation of clinical lesions, and the need for developing better and safer drugs has been unrelenting. The past two decades of research has opened up new areas of the immune pathway that can be targeted in order to control the disease. Therefore, we have seen the emergence of biologics which either target T-cell receptors or inhibit Tumor Necrosis Factor-alpha (TNF-α) or inhibit interleukins (IL) like IL-12, IL-17, IL-17 receptor, and more recently IL-23. Drugs specifically targeting the p19 subunit of IL-23 have shown prom…
Screening of herbal extracts for TLR2- and TLR4-dependent anti-inflammatory effects.
2018
Herbal extracts represent an ample source of natural compounds, with potential to be used in improving human health. There is a growing interest in using natural extracts as possible new treatment strategies for inflammatory diseases. We therefore aimed at identifying herbal extracts that affect inflammatory signaling pathways through toll-like receptors (TLRs), TLR2 and TLR4. Ninety-nine ethanolic extracts were screened in THP-1 monocytes and HeLa-TLR4 transfected reporter cells for their effects on stimulated TLR2 and TLR4 signaling pathways. The 28 identified anti-inflammatory extracts were tested in comparative assays of stimulated HEK-TLR2 and HEK-TLR4 transfected reporter cells to dif…
Molecular evolution of the metazoan extracellular matrix: cloning and expression of structural proteins from the demosponges Suberites domuncula and …
2000
One crucial event during evolution to multicellularity was the development of either direct cell–cell contact or indirect interaction via extracellular matrix (ECM) molecules. The identification of those polypeptides provides conclusive data on the phylogenetic relationship of metazoan phyla and helps us to understand the position of the Metazoa among the other kingdoms. Recently it became evident that the ECM of sponges is amazingly complex; it is composed of fibrous molecules, e.g., collagen, and their corresponding receptors, which are highly similar to those existing in other metazoan phyla. While these data already support the view of monophyly of Metazoa, additional studies are requir…
Effect of LIF-withdrawal on acetylcholine synthesis in the embryonic stem cell line CGR8 is not mediated by STAT3, PI3Ks or cAMP/PKA pathways.
2015
Acetylcholine (ACh) acts as a local cellular signaling molecule and is widely expressed in nature, including mammalian cells and embryonic stem cells. The murine embryonic stem cell line CGR8 synthesizes and releases substantial amounts of ACh. Particularly during early differentiation - a period associated with multiple alterations in geno-/phenotype functions - synthesis and release of ACh are increased by 10-fold. In murine stem cells second messengers of the STAT-3, PI3K and cAMP/PKA pathways are involved in maintaining self-renewal and pluripotency. The present experiments were designed to test whether blockers of these signaling pathways enhance ACh cell content in the presence of LIF…
Aβ and tau toxicities in Alzheimer’s are linked via oxidative stress-induced p38 activation: Protective role of vitamin E
2014
AbstractOxidative stress is a hallmark of Alzheimer’s disease (AD). We propose that rather than causing damage because of the action of free radicals, oxidative stress deranges signaling pathways leading to tau hyperphosphorylation, a hallmark of the disease. Indeed, incubation of neurons in culture with 5 µM beta-amyloid peptide (Aβ) causes an activation of p38 MAPK (p38) that leads to tau hyperphosphorylation. Inhibition of p38 prevents Aβ-induced tau phosphorylation. Aβ-induced effects are prevented when neurons are co-incubated with trolox (the water-soluble analog of vitamin E).We have confirmed these results in vivo, in APP/PS1 double transgenic mice of AD. We have found that APP/PS1 …
Asymmetry Between Pre- and Postsynaptic Transient Nanodomains Shapes Neuronal Communication.
2020
Synaptic transmission and plasticity are shaped by the dynamic reorganization of signaling molecules within pre- and postsynaptic compartments. The nanoscale organization of key effector molecules has been revealed by single-particle trajectory (SPT) methods. Interestingly, this nanoscale organization is highly heterogeneous. For example, presynaptic voltage-gated calcium channels (VGCCs) and postsynaptic ligand-gated ion channels such as AMPA receptors (AMPARs) are organized into so-called nanodomains where individual molecules are only transiently trapped. These pre- and postsynaptic nanodomains are characterized by a high density of molecules but differ in their molecular organization an…
Tiam1 as a Signaling Mediator of Nerve Growth Factor-Dependent Neurite Outgrowth
2010
Nerve Growth Factor (NGF)-induced neuronal differentiation requires the activation of members of the Rho family of small GTPases. However, the molecular mechanisms through which NGF regulates cytoskeletal changes and neurite outgrowth are not totally understood. In this work, we identify the Rac1-specific guanine exchange factor (GEF) Tiam1 as a novel mediator of NGF/TrkA-dependent neurite elongation. In particular, we report that knockdown of Tiam1 causes a significant reduction in Rac1 activity and neurite outgrowth induced by NGF. Physical interaction between Tiam1 and active Ras (Ras- GTP), but not tyrosine phosphorylation of Tiam1, plays a central role in Rac1 activation by NGF. In add…