Browsing Pathways

OX40 is a type 1 transmembrane glycoprotein, reported nearly 30 years ago as a cell surface antigen expressed on activated T cells. Since its discovery, it has been validated as a bone fide costimulatory molecule for T cells and member of the TNF receptor family. Tumor necrosis factor receptor superfamily, member 4 (TNFRSF4), also known as CD134 and OX40 receptor, is a fellow of the TNFR-superfamily of receptors. It is a protein which in humans is encoded by the TNFRSF4 gene which contains 9 exons. It also has been demonstrated to have a key role in the survival and homeostasis of effector and memory T cells in transplantation and autoimmunity. OX40 is not constitutively expressed on resting naive T cells, unlike CD28. As a secondary co-stimulatory immune checkpoint molecule, it expresses after 24 to 72 hours following activation; its ligand, OX40L, is also not expressed on resting antigen presenting cells and resting naive T cells, but is following their activation. Expression of OX40 is dependent on full activation of the T cell and the expression of CD28; without CD28, expression of OX40 is delayed and of fourfold lower levels.

Dopaminergic pathways, sometimes called dopaminergic projections, are the sets of projection neurons in the brain that synthesize and release the neurotransmitter dopamine.[ Individual neurons in these pathways are referred to as dopamine neurons. Dopamine neurons have axons that run the entire length of the pathway. The neurons' somata produce the enzymes that synthesize dopamine, and they are then transmitted via the projecting axons to their synaptic destinations, where most of the dopamine is produced. Dopaminergic nerve cell bodies in such areas as the substantia nigra pars compacta tend to be pigmented due to the presence of the black pigment melanin. Dopaminergic pathways are involved in many functions such as executive function, learning, reward, motivation, and neuroendocrine control. Dysfunction of these pathways and nuclei may be involved in multiple diseases and disorders such as Parkinson's disease, attention deficit hyperactivity disorder, obsessive compulsive disorder, addiction,[6] and restless legs syndrome (RLS)

The Wnt signaling pathway is an ancient and evolutionarily conserved pathway that regulates crucial aspects of cell fate determination, cell migration, cell polarity, neural patterning and organogenesis during embryonic development. The role of Wnt signaling in carcinogenesis has most prominently been described for colorectal cancer, but aberrant Wnt signaling is observed in many more cancer entities.The Wnts are secreted glycoproteins and comprise a large family of nineteen proteins in humans hinting to a daunting complexity of signaling regulation, function and biological output. To date major signaling branches downstream of the Fz receptor have been identified including a canonical or Wnt/β-catenin dependent pathway and the non-canonical or β-catenin-independent pathway which can be further divided into the Planar Cell Polarity and the Wnt/Ca2+ pathways, and these branches are being actively dissected at the molecular and biochemical levels.