adgrl4 Antibody

What is ADGRL4/ELTD1 and what is its biological significance?

ADGRL4/ELTD1 (Adhesion G Protein-Coupled Receptor L4) is an orphan adhesion G protein-coupled receptor (aGPCR) belonging to the 33-member adhesion GPCR family. It plays a crucial role in regulating physiological and tumor angiogenesis, making it an attractive target for anti-cancer therapeutics . ADGRL4 contains large extracellular domains with adhesion motifs, a characteristic feature that distinguishes aGPCRs from other GPCR families .

To study ADGRL4, researchers should consider its expression pattern in endothelial cells and vascular smooth muscle cells, with increased expression observed in tumor vasculature . When designing experiments, it's important to note that ADGRL4 functions as a regulator of angiogenesis, affecting endothelial sprouting and vessel formation both in vitro and in vivo .

How should researchers select and validate ADGRL4 antibodies?

When selecting ADGRL4 antibodies, researchers should verify antibody specificity through validation on tissues known to express ADGRL4 positively and negatively . A methodological approach to validation includes:

• Performing western blot analysis to confirm the detection of ADGRL4 protein at the expected molecular weight (approximately 77.811 kDa for human ADGRL4)

• Using positive control tissues such as human umbilical vein endothelial cells (HUVECs), where ADGRL4 is known to be expressed

• Including negative controls lacking ADGRL4 expression

• Confirming antibody specificity through siRNA knockdown experiments, as demonstrated in studies where ADGRL4/ELTD1 silencing efficacy was determined at both transcript and protein levels

What tissue expression patterns are important to consider when using ADGRL4 antibodies?

ADGRL4 exhibits specific expression patterns that researchers should consider when designing experiments:

• ADGRL4 is detected in the majority of epithelial cells in both tumor and normal tissues

• It is highly expressed in human umbilical vein endothelial cells (HUVECs), making these cells suitable for in vitro studies

• In cancer tissues, ADGRL4 expression is significantly higher in endothelial cells and pericytes compared to healthy controls

• During development, ADGRL4 is detected in the developing metanephros of E14.5 mice

• Expression is observed in both endothelial cells and vascular smooth muscle cells, with increased expression in tumor vasculature

Understanding these expression patterns is crucial for proper experimental design and interpretation of immunostaining results.

What are the key characteristics of ADGRL4 protein structure?

ADGRL4 protein has several structural characteristics that are important for researchers to consider:

Researchers should consider these structural characteristics when designing experiments involving protein detection, localization studies, or functional analyses of ADGRL4.

How does ADGRL4/ELTD1 silencing affect endothelial cell metabolism?

ADGRL4/ELTD1 silencing has significant effects on endothelial metabolism, which researchers can investigate using the following methodological approach:

• Perform ADGRL4/ELTD1 silencing in HUVECs using two independent siRNAs

• Validate silencing efficacy at both transcript and protein levels

• Conduct transcriptional profiling followed by metabolomics using liquid chromatography-mass spectrometry

Key findings from such experiments reveal that ADGRL4/ELTD1 silencing:

• Induces expression of ATP Citrate Lyase (ACLY) and the mitochondria-to-cytoplasm citrate transporter SLC25A1

• Affects several metabolites, with cis-aconitic acid, UDP-glucoronate, fructose 2,6-diphosphate, uridine 5-diphosphate, and aspartic acid being elevated, while phosphocreatine, N-acetylglutamic acid, taurine, deoxyadenosine triphosphate, and cytidine monophosphate are depleted

• Impacts pathways including pyrimidine metabolism, alanine aspartate and glutamine metabolism, cysteine and methionine metabolism, taurine metabolism, arginine and proline metabolism, and amino and nucleotide sugar metabolism

• Inhibits lipid droplet formation, suggesting a role in lipid metabolism regulation

These findings indicate that ADGRL4/ELTD1 plays a role in regulating core components of endothelial metabolism, particularly affecting citrate transport and utilization.

What is the relationship between ADGRL4/ELTD1 and the Notch signaling pathway?

Research investigating the relationship between ADGRL4/ELTD1 and the Notch signaling pathway should employ the following methodology:

• Silence ADGRL4/ELTD1 in endothelial cells using validated siRNAs

• Analyze expression changes in Notch pathway components at both mRNA and protein levels

• Validate findings using functional assays to assess Notch pathway activity

Key research findings demonstrate that ADGRL4/ELTD1 silencing affects the Notch signaling pathway by:

• Upregulating Delta Like Canonical Notch Ligand 4 (DLL4)

• Suppressing Jagged Canonical Notch Ligand 1 (JAG1) and Hes Family BHLH Transcription Factor 2 (HES2)

These findings are particularly significant because the Notch pathway is central to endothelial cell angiogenesis. The differential regulation of DLL4 (upregulation) versus JAG1 (suppression) suggests that ADGRL4/ELTD1 may fine-tune Notch signaling to modulate angiogenic responses. When designing experiments to investigate this relationship, researchers should include appropriate readouts for Notch pathway activity and consider the temporal dynamics of these signaling events.

What role does ADGRL4/ELTD1 play in kidney development and disease?

To investigate ADGRL4/ELTD1's role in kidney development and disease, researchers should consider the following experimental approaches:

• Generate and analyze ADGRL4 knockout or conditional knockout mouse models

• Perform histological and functional assessment of kidney development and function

• Analyze ADGRL4 expression in kidney disease samples compared to healthy controls

Key research findings include:

• Adgrf5/Adgrl4 double knockout mice exhibit significantly reduced kidney function, with half dying perinatally and the remainder showing growth impairment and mortality within 3 weeks to 3 months postnatally

• These double-deficient mice develop massive proteinuria and uremia by 7 weeks of age

• Pathological features at 4 weeks include glomerular thrombotic microangiopathy, schistocytes in the subendothelial zone of glomerular capillaries, loss of endothelial fenestration, and fusion of podocyte foot processes

• Interestingly, endothelial-specific deletion of Adgrf5/Adgrl4 using VE-Cad-Cre mice resulted in no renal phenotype, suggesting a function in non-endothelial renal cell types

• ADGRL4 upregulation is associated with IgA nephropathy and lupus nephritis, while showing contradictory associations with diabetic nephropathy (upregulated in mice but not humans)

These findings suggest complex and potentially cell-type specific roles for ADGRL4 in kidney function that require further investigation.

How is ADGRL4/ELTD1 involved in cancer biology and angiogenesis?

Research into ADGRL4/ELTD1's role in cancer biology and angiogenesis should employ the following methodological approaches:

• Analyze ADGRL4 expression in cancer tissues versus normal controls using validated antibodies

• Perform functional studies in vitro using endothelial cell tube formation and sprouting assays

• Investigate the effects of ADGRL4 inhibition on tumor growth and angiogenesis in vivo

• Correlate ADGRL4 expression with clinical outcomes in cancer patients

Key research findings include:

These findings highlight ADGRL4's complex role in tumor angiogenesis and its potential as a therapeutic target, particularly in highly vascularized tumors.

What are the signaling mechanisms of ADGRL4/ELTD1 as an adhesion GPCR?

Investigating ADGRL4/ELTD1 signaling mechanisms presents unique challenges due to its classification as an orphan adhesion GPCR. Researchers should consider the following methodological approaches:

• Apply the aGPCR "Stinger/tethered-agonist Hypothesis" by designing truncated forms of ADGRL4 and peptides analogous to the proposed tethered agonist region

• Perform FRET-based second messenger assays (e.g., IP-1, cAMP) and luciferase-reporter assays (NFAT, NFKB, SRE, SRF-RE, CREB) to establish canonical GPCR activation

• Investigate potential non-canonical signaling pathways through proteomics and phosphorylation studies

Research findings indicate that:

• Unlike other aGPCRs, ADGRL4 does not couple to canonical GPCR pathways (Gαi, Gαs, Gαq, Gα12/13)

• ADGRL4/ELTD1 silencing affects expression of metabolic regulators (ACLY, SLC25A1) and influences the Notch signaling pathway

• The signaling mechanisms of ADGRL4 remain poorly understood, highlighting the need for innovative experimental approaches

These findings suggest that ADGRL4 may signal through non-canonical pathways, and further research is needed to elucidate its precise signaling mechanisms.