CDB15:0001068 MFGE8 — ITGAV

Experimentally validated in Human, Mouse; Orthology-inferred in Human, Rat, Frog, Zebrafish, Chicken, Macaque, Pig, Dog, Cow, Chimp, Horse, Marmoset, Sheep, Mouse

Title

Journal:; Year Published:

Abstract

Essential role for MFG-E8 as ligand for alphavbeta5 integrin in diurnal retinal phagocytosis.

Proceedings of the National Academy of Sciences of the United States of America, 2007; PubMed, Mus Musculus Mfge8 — Mus Musculus Itgav

ABSTRACT: The integrin receptor alphavbeta5 controls two independent forms of interactions of the retinal pigment epithelium (RPE) with adjacent photoreceptor outer segments that are essential for vision. Alphavbeta5 localizes specifically to apical microvilli of the RPE and contributes to retinal adhesion that maintains RPE contacts with intact outer segments at all times. Additionally, alphavbeta5 synchronizes diurnal bursts of RPE phagocytosis that clear photoreceptor outer segment fragments (POS) shed in a circadian rhythm. Dependence of retinal phagocytosis and adhesion on alphavbeta5 receptors suggests that the extracellular matrix ensheathing RPE microvilli contains ligands for this integrin. Here we studied mice lacking expression of functional MFG-E8 to test the contribution of this integrin ligand to alphavbeta5 functions in the retina. Lack of MFG-E8 only minimally reduced retinal adhesion. In contrast, lack of MFG-E8, like lack of alphavbeta5 receptor, eliminated alphavbeta5 downstream signaling involving the engulfment receptor MerTK and peak POS phagocytosis, both of which follow light onset in wild-type retina. MFG-E8-deficient RPE in primary culture retained normal epithelial morphology and levels of apical alphavbeta5 receptors, but showed impaired binding and engulfment of isolated POS. Soluble or POS-bound recombinant MFG-E8 was sufficient to fully restore phagocytosis by MFG-E8-deficient RPE. Furthermore, MFG-E8 supplementation strongly increased POS binding by wild-type and MerTK-deficient RPE, but did not affect POS binding by RPE lacking alphavbeta5. Thus, MFG-E8 stimulates rhythmic POS phagocytosis by ligating apical alphavbeta5 receptors of the RPE. These results identify MFG-E8 as the first extracellular ligand in the retina that is essential for diurnal POS phagocytosis.

Mfge8 promotes obesity by mediating the uptake of dietary fats and serum fatty acids.

Nature medicine, 2014; PubMed, Homo sapiens MFGE8 — Homo sapiens ITGAV

ABSTRACT: Fatty acids are integral mediators of energy storage, membrane formation and cell signaling. The pathways that orchestrate uptake of fatty acids remain incompletely understood. Expression of the integrin ligand Mfge8 is increased in human obesity and in mice on a high-fat diet, but its role in obesity is unknown. We show here that Mfge8 promotes the absorption of dietary triglycerides and the cellular uptake of fatty acid and that Mfge8-deficient (Mfge8(-/-)) mice are protected from diet-induced obesity, steatohepatitis and insulin resistance. Mechanistically, we found that Mfge8 coordinates fatty acid uptake through αvβ3 integrin- and αvβ5 integrin-dependent phosphorylation of Akt by phosphatidylinositide-3 kinase and mTOR complex 2, leading to translocation of Cd36 and Fatp1 from cytoplasmic vesicles to the cell surface. Collectively, our results imply a role for Mfge8 in regulating the absorption and storage of dietary fats, as well as in the development of obesity and its complications.

Basic Information on MFGE8

Ligand Name: milk fat globule EGF and factor V/VIII domain containing

Other Symbols: SPAG10, SED1, EDIL1, BA46, OAcGD3S, HsT19888, MFG-E8, hP47

Ligand Location: secreted based on hpa, perplexity, uniprot

HGNC Gene Symbol Report: MFGE8

GeneCards: MFGE8

HGNC Gene Group: unknown

Functional Annotations for MFGE8

Gene Ontologies: PAN-GO, AmiGO 2

Expression Profile: Human Protein Atlas (RNA and protein), Human Cell Atlas (RNA), GEPIA cancer vs normal (RNA), GeneCards (RNA and protein)

Disease Annotations: MalaCards, OMIM, Open Targets Platform, DISEASES (text mining), AI summary (LLM)

Interactions with other Receptors for MFGE8

MFGE8 — ITGB3 ・ MFGE8 — ITGA8 ・ MFGE8 — ITGB1 ・ MFGE8 — ITGB5

Basic Information on ITGAV

Receptor Name: integrin subunit alpha V

Other Symbols: VNRA, MSK8, VTNR, CD51

Receptor Location: cell membrane based on perplexity, uniprot

HGNC Gene Symbol Report: ITGAV

GeneCards: ITGAV

HGNC Gene Group: CD molecules, Integrins

Functional Annotations for ITGAV

Gene Ontologies: PAN-GO, AmiGO 2

Expression Profile: Human Protein Atlas (RNA and protein), Human Cell Atlas (RNA), GEPIA cancer vs normal (RNA), GeneCards (RNA and protein)

Disease Annotations: MalaCards, OMIM, Open Targets Platform, DISEASES (text mining), AI summary (LLM)

Interactions with other Ligands for ITGAV

ADAM15 — ITGAV ・ ADAM9 — ITGAV ・ ANGPTL3 — ITGAV ・ AZGP1 — ITGAV ・ COL1A1 — ITGAV ・ COL4A3 — ITGAV ・ CCN1 — ITGAV ・ EDIL3 — ITGAV ・ FBN1 — ITGAV ・ FGA — ITGAV ・ FGB — ITGAV ・ FGG — ITGAV ・ FN1 — ITGAV ・ IBSP — ITGAV ・ ICAM4 — ITGAV ・ L1CAM — ITGAV ・ LAMA4 — ITGAV ・ NID1 — ITGAV ・ SPP1 — ITGAV ・ TGFB1 — ITGAV ・ TNC — ITGAV ・ VTN — ITGAV ・ CX3CL1 — ITGAV ・ CXCL12 — ITGAV ・ FNDC5 — ITGAV ・ PLA2G2A — ITGAV ・ ADAM23 — ITGAV ・ AGRN — ITGAV ・ ANGPT2 — ITGAV ・ CCN3 — ITGAV ・ CD40LG — ITGAV ・ COL18A1 — ITGAV ・ COMP — ITGAV ・ DMP1 — ITGAV ・ EGFL7 — ITGAV ・ FBLN2 — ITGAV ・ FCER2 — ITGAV ・ FGF1 — ITGAV ・ FGF2 — ITGAV ・ HMGB1 — ITGAV ・ IGF1 — ITGAV ・ IGF2 — ITGAV ・ IL1B — ITGAV ・ NRG1 — ITGAV ・ PECAM1 — ITGAV ・ PLAUR — ITGAV ・ POSTN — ITGAV ・ PTN — ITGAV ・ TGFB3 — ITGAV ・ THBS1 — ITGAV ・ THY1 — ITGAV ・ VWF — ITGAV