Ripk3 Knockout H9c2(2-1) Cell Line

The Ripk3 Knockout H9c2(2-1) Cell Line is a CRISPR/Cas9-edited rat cardiomyoblast line featuring targeted disruption of the Ripk3 gene, which encodes receptor-interacting serine/threonine-protein kinase 3 (RIPK3). This loss-of-function model enables investigation of necroptosis and inflammatory signaling in a cardiac-specific context. Derived from the H9c2(2-1) subclone of BDIX embryonic rat heart tissue, the knockout retains key parental characteristics while eliminating RIPK3 expression.

H9c2(2-1) is a subclone of the H9c2 rat cardiomyoblast line, originally isolated from embryonic ventricular tissue, and retains the capacity for myogenic differentiation into multinucleated myotubes. This well-characterized line expresses cardiac markers and exhibits electrophysiological properties of cardiomyocytes, providing a physiologically relevant model for cardiac cell death, survival, and inflammation. The knockout derivative maintains this differentiation potential, enabling RIPK3 functional studies in both proliferative myoblasts and differentiated cardiac muscle cells.

RIPK3 is a central kinase in necroptosis, a regulated necrotic cell death pathway. It is activated by upstream ligands such as TNF-??, FasL, TRAIL, LPS, and dsRNA, leading to necrosome formation with RIPK1 and TRIF. Active RIPK3 phosphorylates MLKL, prompting its oligomerization, membrane translocation, and pore formation that releases DAMPs. RIPK3 also promotes inflammation via NLRP3 inflammasome activation and NF-??B-mediated cytokine production, including IL-1?? and IL-18. Interactions with ZBP1, HSP90, PGAM5, FADD, and caspase-8 modulate RIPK3-dependent signaling outcomes.

In H9c2(2-1) cells, RIPK3-mediated necroptosis contributes to myocardial ischemia-reperfusion injury and inflammatory cardiomyopathy. Knockout of Ripk3 abolishes necroptotic death induced by stimuli such as TNF-?? plus caspase inhibition or hypoxia-reoxygenation, conferring protection against cardiomyocyte loss and reducing inflammatory mediator release. This clean genetic system enables dissection of necroptosis from apoptosis or pyroptosis and supports studies of RIPK3??s role in inflammatory signaling within cardiac cells, including regulation of the NLRP3 inflammasome and NF-??B targets.

This knockout cell line is ideal for studying RIPK1-RIPK3-MLKL signaling, screening RIPK3 inhibitors, and modeling ischemia-reperfusion injury. Typical assays include western blotting for phospho-MLKL, LDH release, propidium iodide uptake, cell viability assays (MTT/CCK-8), flow cytometry, RT-qPCR for cytokines, immunofluorescence for MLKL translocation, and co-immunoprecipitation of necrosome components. Caspase activity assays distinguish necroptosis from apoptosis, with the knockout serving as a specificity control. For technical support, contact Ascent Research.