Cytokines

Key Biological Properties: Visfatin is involved in various physiological processes, including inflammation, apoptosis, and metabolism . It exhibits pro-inflammatory and immunomodulating properties .

Expression Patterns: Visfatin is ubiquitously expressed in various tissues, including skeletal muscles, liver, cardiomyocytes, and brain cells . It is also found in white blood cells and adipocytes .

Tissue Distribution: Visfatin is predominantly expressed in visceral fat compared to subcutaneous fat . It is also present in the heart, liver, kidneys, muscle, brain, spleen, bone marrow, and placenta .

Primary Biological Functions: Visfatin plays a crucial role in NAD biosynthesis, which is essential for cellular metabolism and energy production . It also has insulin-mimetic effects, facilitating glucose uptake in adipocytes and myocytes .

Role in Immune Responses: Visfatin activates human leukocytes and induces cytokine production, including IL-1β, TNF-α, and IL-6 . It enhances the immune response by increasing the surface expression of costimulatory molecules and promoting the activation of monocytes .

Pathogen Recognition: Visfatin is involved in the innate immune response by regulating the synthesis of certain inflammatory cytokines .

Mechanisms with Other Molecules and Cells: Visfatin interacts with various signaling pathways, including NF-κB, phosphatidylinositol 3-kinase (PI3K), and MAPK-related pathways . It binds to the insulin receptor and activates downstream signaling cascades, such as tyrosine phosphorylation and protein kinase β activation .

Binding Partners: Visfatin binds to the insulin receptor at a site distinct from that of insulin, causing hypoglycemia by reducing glucose release from liver cells and stimulating glucose utilization in adipocytes and myocytes .

Downstream Signaling Cascades: Visfatin activates several intracellular signaling pathways, including the PI3K/AKT signaling pathway, Hippo signaling pathway, and Rap1 signaling pathway .

Transcriptional Regulation: Visfatin expression is regulated by various factors, including anti-diabetic thiazolidinediones, insulin, and glucose . It is also influenced by hormones such as progesterone, estradiol, and human chorionic gonadotropin .

Post-Translational Modifications: Visfatin undergoes post-translational modifications that affect its activity and stability. These modifications include phosphorylation and acetylation .

Biomedical Research: Visfatin is a valuable biomarker in metabolic and inflammatory diseases. It is used in research to study its role in obesity, diabetes, and cardiovascular diseases .

Diagnostic Tools: Visfatin levels are measured in clinical settings to assess metabolic health and diagnose conditions such as type 2 diabetes mellitus and atherosclerosis .

Therapeutic Strategies: Targeting visfatin’s enzymatic activity and signaling pathways offers potential therapeutic strategies for treating metabolic disorders and inflammatory diseases .

Development: Visfatin plays a role in embryonic development and is expressed in the placenta, where it regulates trophoblast function and placental development .

Aging: Visfatin levels are associated with age-related metabolic changes and may influence the aging process through its effects on NAD biosynthesis and cellular metabolism .

Disease: Visfatin is implicated in various diseases, including obesity, type 2 diabetes mellitus, cardiovascular diseases, and inflammatory conditions . Its dysregulation is linked to pathological conditions such as polycystic ovary syndrome and pregnancy disorders .