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Oncostatin M (OSM) is a pleiotropic cytokine belonging to the Interleukin-6 (IL-6) family; it participates in various inflammatory responses, such as wound healing, liver regeneration, and bone remodeling. In addition to OSM, members of the IL-6 family include IL-6, Leukemia Inhibitory Factor (LIF), IL-11, IL-27, IL-31, Cardiotrophin-1 (CT-1), Ciliary Neurotrophic Factor (CNTF), and Cardiotrophin-like Cytokine 1 (CLCF1). OSM is widely expressed *in vivo*, and it can be produced by a variety of immune cells, including T cells, monocytes/macrophages, and neutrophils.

The receptor complexes of the IL-6 receptor family all contain the GP130 subunit. The receptor complexes for OSM are heterodimers; based on the identity of the second subunit within the complex, these receptors can be classified into two types: Type I and Type II. The Type I OSM receptor complex consists of the α-subunit GP130 and the β-subunit LIFRβ (LIF Receptor β-subunit), whereas the Type II OSM receptor complex consists of the α-subunit GP130 and the β-subunit OSMRβ (OSM Receptor β-subunit). When OSM and the two subunits of its receptor complex are simultaneously present, OSM first forms a low-affinity heterodimer with GP130; this heterodimer then recruits and binds to either OSMR or LIFR, thereby activating multiple signaling pathways, including the JAK/STAT, MAPK, JNK, and PI3K/AKT pathways.

The OSMR & IL6ST Dimerization CHO Reporter Gene Drug Target Model effectively simulates the *in vivo* signal transduction process of OSM; the underlying principle is illustrated in the figure below.

Figure 1. Schematic Diagram of the OSMR & IL6ST Dimerization CHO Cell Model

Figure 2. Recombinant OSMR&IL6ST Dimerization CHO stably expressing OSMR&IL6ST.

Figure 3. Dose Response of Recombinant Human OSM in OSMR&IL6ST Dimerization CHO( C52).

Figure 4. Inhibition of Recombinant Human OSM induced OSMR&IL6ST Dimerization by OSMR Blocking Ab in OSMR&IL6ST Dimerization CHO (C52).

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  CHO-K1 Human OMSR&IL6ST Dimerization Cell 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.