Eva1a Antibody

What is EVA1A and what are its primary functions in cellular processes?

EVA1A, also known as TMEM166 (transmembrane protein 166) or FAM176A (family with sequence similarity 176), is a lysosome and endoplasmic reticulum-associated protein that functions as a regulator of programmed cell death, mediating both autophagy and apoptosis . This highly conserved protein is 152 amino acids long with a molecular weight of approximately 17.5 kDa . EVA1A stimulates autophagy by interacting with the WD repeats of ATG16L1 and functions downstream of the BECN1 complex while positioned upstream of ATG16L1 . It may be responsible for ATG12-5/16L1 recruitment to the isolation membrane and is potentially a component of the autophagosomal membrane closely related to autophagosome development and maturation .

What tissue expression patterns does EVA1A exhibit?

EVA1A demonstrates a cell- and tissue-specific expression pattern. It is primarily expressed in the lung, kidney, liver, pancreas, and placenta, but shows minimal or no expression in the heart and skeletal muscle . Notably, EVA1A expression is significantly decreased in many types of human tumors, including gastric cancer, esophagus cancer, adrenal cortical carcinoma, pituitary adenoma, and parathyroid adenoma, suggesting its potential role as a tumor suppressor .

What are the common applications for EVA1A antibodies in research?

EVA1A antibodies are primarily used in the following research applications:

Western Blot and Immunohistochemistry are the most widely used applications for EVA1A antibodies in research settings . For immunostaining, samples are typically fixed with 4% paraformaldehyde, permeabilized with 0.1% Triton X-100, and blocked with 5% goat serum before incubation with primary EVA1A antibodies .

How is EVA1A involved in cardiovascular disease research?

EVA1A plays a significant role in cardiovascular pathologies, particularly in atherosclerosis and cardiac remodeling. Hemodynamic wall shear stress (WSS) exerted on the endothelium by flowing blood determines the spatial distribution of atherosclerotic lesions . EVA1A expression is differentially regulated in areas of disturbed flow (DF) with low WSS compared to areas of undisturbed flow (UF) with high WSS .

Research indicates that EVA1A improves atherosclerosis through increasing re-endothelialization of injured arteries by promoting endothelial cell migration via the Rac1/Cdc42/Arpc1b pathway . EVA1A deletion accelerates atherosclerosis development, as evidenced by increased lesion formation and neointimal hyperplasia . Additionally, EVA1A ameliorates cardiac remodeling by inhibiting cardiac hypertrophy and fibrosis through promoting autophagy via inhibition of the mTOR pathway .

How can researchers effectively study EVA1A's dual role in autophagy and apoptosis?

Studying EVA1A's dual role requires careful experimental design with appropriate controls:

• Time-course experiments: Autophagy often precedes apoptosis in EVA1A overexpression models, so temporal studies are crucial .

• Dual labeling strategies: Co-staining with autophagy markers (LC3, ATG16L1) and apoptosis markers (active caspase-3) allows distinction between the two processes .

• Pharmacological manipulation: Using autophagy inhibitors (chloroquine, 3-methyladenine) or apoptosis inhibitors (Z-VAD-FMK) helps delineate which pathway is predominant.

• Genetic approaches: siRNA silencing of EVA1A in vitro or morpholinos in zebrafish models helps understand EVA1A-dependent processes .

• Stress conditions: Comparing EVA1A function under different stress conditions (nutrient deprivation, oxidative stress) reveals context-dependent roles.

Research has demonstrated that EVA1A overexpression inhibits tumor cell proliferation and induces both autophagy and apoptosis even under nutrient-rich conditions, with autophagy typically preceding cell death .

What are the optimal validation strategies for EVA1A antibodies?

Proper validation of EVA1A antibodies requires multiple complementary approaches:

• Positive and negative tissue controls: Using tissues known to express EVA1A (lung, kidney, liver) versus those with minimal expression (heart, skeletal muscle) .

• Genetic knockdown/knockout verification: Testing antibody specificity using siRNA-treated cells or knockout models. Researchers have validated EVA1A antibodies using siRNA in human endothelial cells and morpholinos in zebrafish models .

• Western blot analysis: Confirming the detection of a single band at the expected molecular weight (17.5 kDa) .

• Peptide competition assay: Pre-incubating the antibody with the immunizing peptide should abolish specific staining.

• Cross-reactivity testing: Evaluating antibody performance across species when conducting comparative studies (EVA1A is conserved in humans, chimpanzees, rats, mice, and dogs) .

How does EVA1A expression correlate with cancer progression?

EVA1A expression profiles in cancer tissues reveal important patterns:

Expression profile analyses indicate that EVA1A protein levels in most cancer tissues are negative or lower compared with normal tissues . In vivo and in vitro experiments demonstrate that EVA1A overexpression inhibits tumor cell proliferation and induces both autophagy and apoptosis, suggesting EVA1A functions as a tumor suppressor . The restoration of EVA1A in certain cancer cell lines can induce cell death through both autophagy and apoptosis pathways, indicating EVA1A could potentially be combined with chemotherapy in cancer treatment .

What role does EVA1A play in liver pathologies?

EVA1A-mediated autophagy has significant implications in liver diseases:

• Acute Liver Failure (ALF): EVA1A-mediated autophagy improves ALF by maintaining mitochondrial homeostasis. Research with EVA1A knockout mice showed that reduction of autophagy led to mitochondrial swelling in ALF, causing insufficient ATP production and hepatocyte apoptosis .

• Hepatic Ischemia/Reperfusion (I/R) Injury: EVA1A improves hepatic I/R injury by inhibiting NLRP3 inflammasome activation through inducing autophagy in Kupffer cells .

• Therapeutic potential: Overexpression of EVA1A using adeno-associated virus (AAV-EVA1A) or treatment with the autophagy inducer rapamycin can increase autophagy and improve liver injury in EVA1A knockout mice with ALF, suggesting therapeutic applications .

How should researchers design experiments to investigate EVA1A's role in endothelial dysfunction?

When studying EVA1A in endothelial cells, researchers should consider the following experimental design elements:

• Flow conditions: Implement models that simulate both disturbed flow (DF) with low WSS and undisturbed flow (UF) with high WSS to study differential EVA1A expression .

• In vivo models: Use wire-injured carotid arteries in mouse models, particularly EVA1A knockout mice and endothelial cell-specific EVA1A knockout mice to assess re-endothelialization capacity .

• Atherosclerosis models: Consider EVA1A−/−ApoE−/− mice to study the role of EVA1A in atherosclerosis progression .

• Molecular pathway investigation: Examine the Rac1/Cdc42/Arpc1b pathway components, as proteomic analysis has identified Arpc1b as a downstream target of EVA1A in endothelial cells .

• Migration assays: Conduct in vitro migration assays with EVA1A silencing (si-EVA1A) or overexpression (Ad5-EVA1A) to assess functional impacts on endothelial cell behavior .

What are the optimal immunostaining protocols for EVA1A detection?

For optimal detection of EVA1A in immunostaining applications, researchers should follow these guidelines:

• Fixation: Use 4% paraformaldehyde for tissue and cell samples to maintain protein structure and epitope accessibility .

• Permeabilization: Apply 0.1% Triton X-100 in PBS to allow antibody access to intracellular EVA1A .

• Blocking: Block with 5% goat serum in PBS for 1 hour to minimize non-specific binding .

• Primary antibody incubation: Incubate samples with anti-EVA1A antibody for 16 hours at 4°C for optimal binding .

• Secondary detection: Use appropriate AlexaFluor-conjugated secondary antibodies (AlexaFluor488 or AlexaFluor568) for visualization, with a 2-hour incubation at room temperature .

• Nuclear counterstaining: Apply DAPI or To-Pro-3 for nuclear visualization .

• Mounting: Mount samples in ProLong Gold or similar medium for preservation and visualization .

How can researchers quantify EVA1A expression in tissue samples?

For accurate quantification of EVA1A expression in tissues:

• En face staining: For vascular tissues, use en face staining to assess endothelial cell expression of EVA1A at different regions (e.g., inner curvature vs. outer curvature of aortic arch) .

• Co-staining strategy: Always co-stain with cell-type specific markers (e.g., CD31 for endothelial cells) to accurately identify target cells .

• Image acquisition: Use confocal microscopy for high-resolution imaging and z-stack acquisition to capture the full tissue depth .

• Analysis software: Employ software like Fiji for quantitative analysis of fluorescence intensity and calculation of positive cell frequencies .

• Reference standards: Include control samples with known EVA1A expression levels to normalize between experimental batches.

• Blinded analysis: Conduct blinded quantification to prevent observer bias in fluorescence intensity measurements.

How does EVA1A mechanistically contribute to autophagy regulation?

EVA1A contributes to autophagy regulation through specific molecular interactions:

• ATG16L1 interaction: EVA1A stimulates autophagy by directly interacting with the WD repeats of ATG16L1, a key component of the autophagy machinery .

• Position in autophagy pathway: EVA1A acts downstream of the BECN1 complex and upstream of ATG16L1 .

• Recruitment function: EVA1A may be responsible for ATG12-5/16L1 recruitment to the isolation membrane, a critical step in autophagosome formation .

• Autophagosomal membrane incorporation: EVA1A potentially functions as a component of the autophagosomal membrane itself, contributing to autophagosome development and maturation .

• Pathway regulation: In various disease contexts, EVA1A regulates autophagy through inhibition of the mTOR/RPS6KB1 pathway or the PIK3CA-AKT/mTOR pathway .

This mechanistic understanding provides researchers with specific targets for investigating EVA1A's functions in different cellular contexts and disease models.

What experimental approaches are most effective for studying EVA1A-mediated pathways?

To effectively study EVA1A-mediated pathways, researchers should consider these approaches:

• Protein interaction studies: Use co-immunoprecipitation with EVA1A antibodies followed by mass spectrometry to identify novel interaction partners.

• Pathway analysis: Evaluate the status of known downstream pathways (mTOR/RPS6KB1, Rac1/Cdc42/Arpc1b, PIK3CA-AKT/mTOR, Hippo) when manipulating EVA1A expression .

• Genetic manipulation: Employ CRISPR/Cas9, shRNA, or siRNA approaches for precise genetic manipulation of EVA1A .

• Animal models: Utilize EVA1A knockout mice, zebrafish morpholino models, or tissue-specific knockouts to study in vivo effects .

• Rescue experiments: Perform rescue experiments with wild-type or mutant EVA1A to confirm specificity of observed phenotypes.

• Pharmacological modulation: Combine EVA1A studies with autophagy inducers (rapamycin) or inhibitors (chloroquine) to understand pathway interactions .

These approaches can be systematically combined to develop a comprehensive understanding of EVA1A's role in various physiological and pathological contexts.