Committed to providing comprehensive support for global drug development

G protein-coupled receptors (GPCRs) are transmembrane protein receptors characterized by their interaction with a diverse array of ligands, including endogenous neurotransmitters and hormones, as well as exogenous natural and synthetic compounds. Upon binding to a receptor, agonists trigger the activation of signaling pathways; conversely, antagonists block agonist-mediated receptor activation. Inverse agonists, in addition to interfering with agonists much like antagonists do, also suppress the constitutive activity of the receptor. 

Glucose-dependent insulinotropic polypeptide (also known as gastric inhibitory polypeptide, GIP), glucagon-like peptide-1 (GLP-1), and glucagon (GCG) are peptide hormones responsible for maintaining glucose homeostasis. Their cognate receptors—GIPR, GLP-1R, and GCGR—belong to the Class B1 family of G protein-coupled receptors (GPCRs). The gastric inhibitory polypeptide receptor (GIPR) is the specific receptor for GIP; it is a GPCR characterized by the presence of seven transmembrane domains. Upon binding to the GIP hormone, it enhances the synthesis and secretion of insulin by pancreatic beta cells in a glucose-dependent manner. GIPRs located on pancreatic beta cells play a pivotal role in the signaling cascade that ultimately leads to the release of insulin in response to elevated blood glucose levels.

The HEK293 Human GIPR CRE-Luc Cell Line model accurately simulates the in vivo signal transduction process of GIPR. The underlying principle is illustrated in the figure below.

Figure 1. Schematic diagram of the HEK293 Human GIPR CRE-Luc Cell Line model

Figure 2. Recombinant GIPR/CRE-Luc/HEK293 stably expressing human GIPR.

Figure 3. Dose Response of GIP in GIPR CRE-Luc HEK293(C37).

Figure 4. HTRF cAMP Assay with GIPR CRE-Luc HEK293(C37).

Cell Resuscitation
1)Rapidly thaw the frozen cells in a 37 °C water bath for approximately 60 seconds. Once thawed (which may take slightly less or more than 60 seconds), immediately transfer the cell suspension from the cryovial into a 15 mL centrifuge tube containing 10 mL of pre-warmed HEK293 Human GIPR CRE-Luc Cell Line complete culture medium.
2)Centrifuge cells at 1000 rpm for 5 min to remove medium, then resuspend cells in 5 mL of pre-warmed complete medium.
3)Transfer the cell suspension into a T25 culture flask and incubate at 37 °C with 5% CO₂.
4)After approximately 24–36 hours, replace the medium or passage the cells to remove non-adherent dead cells.

Subculturing procedure
1)When the cell density reaches the appropriate confluency for passaging, wash the cells with PBS, then add 1 mL trypsin to detach the cells. When more than 80% of the cells detach upon gently tapping the culture flask, add complete culture medium to terminate digestion. Gently pipette to obtain a single-cell suspension, transfer to a 15 mL centrifuge tube, and centrifuge at 1000 rpm for 5 minutes.

2)Discard supernatant after centrifugation. Resuspend cells in fresh medium to a single-cell suspension and transfer to a new culture flask for continued growth.

Cell Freezing
After trypsinization and centrifugation of cells from each T75 flask or 10 cm culture dish, discard the supernatant. Add 2 mL of cryopreservation medium (90% FBS + 10% DMSO), gently resuspend thoroughly, and aliquot into two cryovials. Immediately place the cryovials into a controlled-rate freezing container (e.g., Nalgene 5100-0001), fill with isopropanol to the indicated level, and store at −80 °C. After 24 hours, transfer the cryovials to liquid nitrogen for long-term storage.