Signaling Pathway
A series of molecular events inside a cell that transmits a signal from a receptor to produce a biological response.
Receptor Expression
The presence and abundance of a receptor in a cell or tissue, which influences responsiveness to ligands.
Upregulation
An increase in the expression of a gene, protein, or receptor, often leading to enhanced pathway activity.
Downregulation
A decrease in the expression of a gene, protein, or receptor, often reducing sensitivity or pathway signaling.
Gene Expression
The process by which genetic information is used to synthesize functional molecules (RNA and proteins).
Transcription
Conversion of DNA information into RNA, a key step in controlling protein production.
Translation
Conversion of RNA into protein by ribosomes, determining which proteins are produced in a cell.
Kinase
An enzyme that modifies proteins by adding phosphate groups (phosphorylation), often regulating signaling pathways.
Phosphorylation
A chemical modification involving addition of a phosphate group to a protein, altering activity or signaling.
MAPK Pathway
A major signaling pathway involved in cell growth, differentiation, stress response, and gene regulation.
PI3K/AKT Pathway
A signaling pathway involved in survival, metabolism, and growth; commonly studied in insulin and growth factor signaling.
mTOR Signaling
A central regulatory pathway controlling protein synthesis, nutrient sensing, and cell growth.
Inflammatory Cytokines
Signaling proteins (such as IL-6 and TNF-α) that modulate immune activity and inflammation in tissues.
Fibrosis
Excessive connective tissue formation in response to chronic injury or inflammation, often impacting organ function.
Extracellular Matrix (ECM)
A network of proteins and molecules surrounding cells that provides structural support and influences signaling.
Tissue Perfusion
Delivery of blood (and oxygen/nutrients) to tissue; often studied in recovery, inflammation, and repair contexts.
Neuroinflammation
Inflammatory signaling in the nervous system involving glial activation and cytokine release.
Blood–Brain Barrier (BBB)
A selective barrier that regulates which substances can enter the brain from the bloodstream.
Bioavailability
The fraction of a compound that reaches the intended site of action in an active form under defined conditions.
Half-Life
The time required for the amount of a compound to decrease by 50% through metabolism, degradation, or clearance.
Clearance
The rate at which a compound is removed from a system, often influenced by metabolism and excretion pathways.
Biodistribution
How a compound distributes across organs and tissues over time, often measured using labeled tracers.
Biomarker
A measurable indicator used to assess biological processes, pathway activity, or experimental response.
Validation
Confirmation that a method, signal, or measurement is reliable and accurately reflects what it is intended to measure.