IGF2

Insulin-like Growth Factor 1 (IGF-1)

Insulin-like Growth Factor 1 (IGF-1) is a protein that in humans is encoded by the IGF1 gene. It is a hormone similar in molecular structure to insulin and plays an important role in childhood growth and continues to have anabolic effects in adults.

Structure

IGF-1 is a small protein with a molecular weight of approximately 7.6 kDa. It consists of 70 amino acids in a single chain with three intramolecular disulfide bridges. The structure of IGF-1 is similar to that of insulin, and it is part of a family of proteins known as the insulin-like growth factors.

Function

IGF-1 is primarily produced in the liver as an endocrine hormone and is also produced in target tissues in a paracrine/autocrine fashion. It is a major mediator of the effects of growth hormone (GH). IGF-1 stimulates systemic body growth and has growth-promoting effects on almost every cell in the body, especially skeletal muscle, cartilage, bone, liver, kidney, nerve, skin, and lungs.

IGF-1 is involved in cell growth, differentiation, and survival. It binds to the IGF-1 receptor (IGF1R) and activates intracellular signaling pathways, including the PI3K/AKT pathway and the MAPK/ERK pathway, which are critical for cell proliferation and survival.

Clinical Significance

IGF-1 levels are used as a diagnostic tool in various conditions. Elevated levels of IGF-1 can indicate acromegaly, a condition caused by excess growth hormone. Conversely, low levels of IGF-1 can be indicative of growth hormone deficiency or malnutrition.

IGF-1 has been studied for its potential role in aging and longevity. Some research suggests that lower levels of IGF-1 may be associated with increased lifespan, while others indicate that IGF-1 is necessary for maintaining muscle mass and function in older adults.

Therapeutic Uses

Recombinant IGF-1 is used in the treatment of growth failure in children with severe primary IGF-1 deficiency. It is also being investigated for its potential in treating muscle wasting diseases, diabetes, and other conditions.

Research

Ongoing research is exploring the role of IGF-1 in cancer, as it can promote cell proliferation and inhibit apoptosis, potentially contributing to tumor growth. The IGF-1 signaling pathway is a target for cancer therapy development.

Also see

• Growth hormone
• Insulin
• IGF-1 receptor
• Acromegaly
• Growth hormone deficiency