ITLN - Intelectin (Omentin) | Elisa - Clia - Antibody - Protein

Background:

Intelectin, also known as omentin, is a protein encoded by the ITLN gene. It belongs to the intelectin family of lectins, which are carbohydrate-binding proteins involved in immune regulation, host defense, and metabolic homeostasis. Intelectin was first identified as a novel lectin-like protein expressed in the intestinal mucosa of mice. Subsequent research revealed its expression in various tissues and its association with metabolic and inflammatory processes. Intelectin is expressed in a variety of tissues, including the intestine, adipose tissue, and endothelial cells. It is particularly abundant in visceral adipose tissue, where it is predominantly secreted by adipocytes (fat cells). Its expression levels can be influenced by various factors, including obesity, inflammation, and insulin sensitivity. Intelectin plays a role in metabolic regulation and glucose homeostasis. It has been implicated in insulin sensitivity, adipocyte differentiation, and lipid metabolism. Higher levels of intelectin expression have been associated with improved insulin sensitivity and reduced risk of metabolic disorders such as obesity and type 2 diabetes. Intelectin exhibits also anti-inflammatory properties by modulating immune responses and suppressing inflammation. It can inhibit the production of pro-inflammatory cytokines and chemokines and promote the polarization of macrophages toward an anti-inflammatory phenotype, thereby attenuating inflammatory response. Intelectin may play a role in vascular function and endothelial health. It has been shown to regulate endothelial cell proliferation, migration, and angiogenesis, suggesting potential implications for cardiovascular health and disease. Alterations in intelectin expression have been implicated in metabolic disorders such as obesity, insulin resistance, and type 2 diabetes. Lower levels of intelectin expression are associated with increased adiposity, impaired glucose metabolism, and a higher risk of metabolic complications.

Protein Structure:

Intelectins are characterized by their unique carbohydrate recognition domains, which allow them to bind to specific sugars. They form disulfide-linked homotrimers and have the following structural features:

• Carbohydrate Recognition Domain (CRD): Essential for binding galactofuranose-containing glycans on microbial surfaces.
• Signal Peptide: Directs the protein to the secretory pathway.
• Disulfide Bonds: Stabilize the trimeric structure, crucial for its function.

Classification and Subtypes:

Intelectins belong to a class of lectins known as X-type lectins. In humans, the primary subtypes are:

• ITLN1 (Intelectin-1 or Omentin-1): Predominantly found in omental adipose tissue and the small intestine.
• ITLN2 (Intelectin-2 or Omentin-2): Less well-characterized but shares similar functions with ITLN1.

Function and Biological Significance:

Intelectins play several crucial roles in the body:

• Innate Immunity: They bind to specific carbohydrates on the surface of pathogens, facilitating their recognition and clearance by the immune system. This helps in protecting the body against bacterial and viral infections.
• Metabolic Regulation: ITLN1 is involved in glucose metabolism and insulin sensitivity. Higher levels of ITLN1 are associated with improved insulin sensitivity and anti-inflammatory effects, making it a significant player in metabolic health.
• Cell Adhesion and Signaling: Intelectins can influence cell-cell interactions and signaling pathways, impacting processes such as inflammation and tissue repair.

Interactions:

• Pathogens: ITLN1 binds to microbial glycans, aiding in the immune response against bacteria and viruses.
• Adipokines: ITLN1 interacts with other adipokines, influencing metabolic processes and inflammation.
• Cell Surface Receptors: It can interact with receptors on immune cells, modulating their activity and promoting pathogen clearance.

Clinical Issues:

• Metabolic Disorders: Altered levels of ITLN1 are linked to metabolic diseases like obesity, type 2 diabetes, and metabolic syndrome. Lower levels of ITLN1 are often observed in individuals with these conditions.
• Inflammatory Diseases: Due to its anti-inflammatory properties, dysregulation of ITLN1 is associated with inflammatory diseases, including cardiovascular diseases and inflammatory bowel disease.
• Cancer: Emerging evidence suggests that intelectins may play a role in tumor biology, although the mechanisms are not fully understood. They could influence tumor growth and metastasis through their effects on inflammation and metabolism.

Summary:

Intelectins, particularly ITLN1 (Omentin-1), are multifunctional proteins involved in innate immunity, metabolic regulation, and inflammatory processes. They recognize and bind specific carbohydrates on pathogens, enhancing immune defense. Additionally, ITLN1 plays a crucial role in metabolic health, influencing insulin sensitivity and inflammatory responses. Alterations in intelectin levels are associated with various clinical conditions, including metabolic disorders, inflammatory diseases, and potentially cancer, making them important biomarkers and potential therapeutic targets.