Target Interpretation | Cytokine AREG
Basic Information of AREG
AREG (Amphiregulin) is an important member of the epidermal growth factor (EGF) family. It was first isolated from the culture medium of the human breast cancer cell line MCF-7. The name "Amphiregulin" derives from its bidirectional regulatory effect on cell growth: it promotes cell proliferation at low concentrations and inhibits cell growth at high concentrations.The AREG gene is located on human chromosome 4q13.3, encoding a precursor protein that is a transmembrane glycoprotein containing 252 amino acids. After cleavage by proteases, the precursor protein releases a biologically active soluble mature peptide. This mature peptide contains an epidermal growth factor-like domain homologous to other members of the EGF family, which is critical for AREG to bind to its corresponding receptors and exert biological functions.
Mechanism of Action of AREG
Amphiregulin (AREG) exerts its biological effects mainly by binding to the epidermal growth factor receptor (EGFR, also known as HER1). In addition, it can also bind to HER4 (erbB4). When AREG binds to EGFR or HER4, it causes receptor dimerization, which in turn activates the tyrosine kinase activity of the intracellular domain of the receptor, leading to the phosphorylation of tyrosine residues on the receptor itself.The phosphorylated receptor can further activate a series of downstream signal transduction pathways, mainly including the Ras-Raf-MEK-ERK MAPK pathway, PI3K-Akt pathway, and JAK-STAT pathway, etc. The activation of the Ras-Raf-MEK-ERK MAPK pathway can promote cell proliferation, differentiation, and migration; the PI3K-Akt pathway plays an important role in cell survival, anti-apoptosis, and the regulation of cell metabolism; the JAK-STAT pathway is involved in various physiological processes such as cell growth, differentiation, and immune regulation. Through the synergistic effect of these signaling pathways, AREG achieves the regulation of various biological behaviors of cells.
Association of AREG with Diseases
CAREG is abnormally expressed in various cancers and is closely related to the occurrence, development, invasion and metastasis of cancer. In breast cancer, the high expression of AREG can promote the proliferation and metastasis of breast cancer cells by activating EGFR and its downstream signaling pathways, and at the same time enhance the resistance of tumor cells to chemotherapy drugs. In colorectal cancer, AREG can be secreted by stromal cells and tumor cells in the tumor microenvironment, promoting the growth of tumor cells and angiogenesis through autocrine and paracrine means, and accelerating tumor progression. In addition, abnormal expression of AREG has also been confirmed to be associated with poor clinical prognosis in various cancers such as lung cancer, stomach cancer and ovarian cancer.ancer
Inflammatory Diseases
AREG plays an important regulatory role in inflammatory responses. In chronic inflammatory diseases such as rheumatoid arthritis, synovial cells can secrete AREG, which promotes the proliferation of synovial cells and the release of inflammatory factors (such as IL-6, TNF-α, etc.) by activating the EGFR signaling pathway, thereby aggravating joint inflammatory damage and bone destruction. During the onset of asthma, AREG can be secreted by airway epithelial cells and inflammatory cells, participating in processes such as the proliferation of airway smooth muscle cells, airway remodeling, and mucus secretion, thereby exacerbating the pathological changes of asthma.Skin Diseases
AREG plays a significant role in maintaining the normal physiological functions of the skin and in the occurrence and development of skin diseases. During the process of wound healing, AREG is secreted by keratinocytes and others, which can promote the proliferation and migration of keratinocytes, accelerate the re-epithelialization of the wound surface, and facilitate wound healing. In psoriasis, the expression level of AREG is elevated. It can stimulate the excessive proliferation and abnormal differentiation of keratinocytes by activating the EGFR signaling pathway, and also promote the infiltration of inflammatory cells, participating in the formation of psoriasis lesions.Detection of AREG
Samples for Detection
AREG's testing sample sources are quite extensive, including serum, plasma, tissue samples, and cell culture media, etc. Serum and plasma samples can be used to detect the levels of AREG in the circulation, reflecting the overall state of the body. Tissue samples can be used to detect the expression localization and expression level of AREG in specific tissues through immunohistochemistry and other methods, which is helpful for understanding the role of AREG in tissue lesions. Cell culture medium can be used to detect the ability of cells to secrete AREG.
Detection Methods
Enzyme-Linked Immunosorbent Assay (ELISA): This is one of the commonly used methods for detecting AREG, which has the advantages of simple operation, high sensitivity and good specificity. The principle is to coat the anti-AREG antibody on the microplate. After adding the sample to be tested, the AREG in the sample will bind to the coated antibody. Then, the enzyme-labeled secondary antibody is added to form an antibody-antigen-enzyme-labeled secondary antibody complex. Finally, the content of AREG in the sample is determined based on the absorbance value by adding the substrate for color development.
Western Blot(WB): This method can be used to detect the expression level of AREG protein in tissues or cells. The process involves first performing electrophoresis to separate the proteins in the sample, then transferring them onto nitrocellulose membranes or polyvinylidene fluoride membranes. Specific antibodies are used to bind to the AREG proteins on the membranes, and then enzymes or fluorescently labeled secondary antibodies are employed for detection. The expression level of AREG can be semi-quantitatively analyzed based on the gray value of the bands.
Immunohistochemistry (IHC): Mainly used to detect the localization and expression of AREG in tissue sections. By binding specific antibodies against AREG to AREG antigens in tissue sections and then using chromogenic agents for color development, the distribution and expression intensity of AREG in tissue cells can be observed under a microscope, which is helpful for studying the role of AREG in histopathological processes.Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR): This method is used to detect the expression level of AREG mRNA, thereby indirectly reflecting the synthesis of AREG. The principle is to convert mRNA into cDNA through reverse transcription, and then perform PCR amplification using cDNA as a template. During the amplification process, the amount of amplification products is monitored in real time through the accumulation of fluorescence signals. Finally, the relative expression level of AREG mRNA in the sample is calculated based on the amplification curve.
The above-mentioned detection methods each have their own advantages and disadvantages. In actual research, the appropriate detection method can be selected based on the research purpose, sample type, and experimental conditions, etc.
