CTRP3 alleviates cardiac ischemia/reperfusion injury via LAMP1/JIP2/JNK signaling pathway

Abstract

Background: C1q/tumor necrosis factor-related protein 3 (CTRP3) has been reported to be a crucial regulator in myocardial infarction. Nevertheless, the potential molecular mechanism of CTRP3 in ischemia/reperfusion (I/R) injury remains largely unclear. Methods: The cell model of myocardial I/R injury was established by oxygen-glucose deprivation/reoxygenation (OGD/R) of rat cardiomyocyte H9C2. Expression of CTRP3 and lysosomal-associated membrane protein 1 (LAMP1) was detected in H9C2 cells treated with oxygen-glucose deprivation/reoxygenation (OGD/R). H9C2 cells were transfected with overexpression plasmids of CTRP3 (pcDNA-CTRP3) and LAMP1 (pcDNA-LAMP1), or CTRP3 small interfering RNA (si-CTRP3) or/and pcDNA-LAMP1, and cell proliferation, apoptosis and oxidative stress were testified. Co-IP assay was performed to validate the relationship among CTRP3, LAMP1 and JIP2. The role of CTRP3 and LAMP1 in JIP2/JNK pathway was evaluated with Western blot assay. Furthermore, in vivo myocardial I/R injury model was constructed to investigate the effect of CTRP3. Results: Overexpression of CTRP3 and LAMP1 both significantly promoted cell proliferation, inhibited apoptosis and the production of reactive oxygen species (ROS), malondialdehyde (MAD) and cardiac troponin (cTn-I), while silencing CTRP3 exerted the opposite effects, and LAMP1 overexpression reversed the effect of silencing CTRP3 on the aspects above. CTRP3 interacted with LAMP1, and both CTRP3 and LAMP1 bound with JIP2. SP600125 (JNK inhibitor) could restore the effects of CTRP3 or LAMP1 overexpression on the expression of JIP2 and phosphorylated-JNK (p-JNK), proliferation and apoptosis. Moreover, overexpression of CTRP3 improved cardiac I/R injury in vivo . Conclusion: CTRP3 alleviates cardiac I/R injury by elevating LAMP1 and activating JIP2/JNK signaling pathway, which may serve as a potential therapeutic target for I/R injury.

Complement 1q/Tumor Necrosis Factor-Related Proteins (CTRPs): Structure, Receptors and Signaling

“…CTRP3 protects from pressure overload-induced cardiac hypertrophy and heart dysfunction by the inhibition of the p38/CREB/ER stress pathway [62]. Furthermore, as already described in the receptor section, there is evidence that CTRP3 is cardioprotective through LAMP1-mediated activation of the JNK pathway [111,112]. CTRP15 shows anti-apoptotic and anti-inflammatory functions in the heart and in macrophages by AMPK-independent activation of the sphingosine-1phosphate (S1P)/cAMP/Akt signaling pathway [57].…”

“…CTRP3 was found to interact with the lysosomal-associated membrane protein 1 (LAMP1) in rat H4IIE hepatoma cells [18]. This interaction has also been confirmed in murine H9c2 cells where CTRP3 and LAMP1 promote proliferation and inhibit apoptosis in response to oxygen-glucose deprivation/reoxygenation treatment [111]. Moreover, there is evidence from inhibitor studies and coimmunoprecipitation experiments that CTRP3 and LAMP1 signal by JIP2/NUMB-assisted activation of cJun N-terminal kinases to protect from I/R injury [111,112].…”

“…This interaction has also been confirmed in murine H9c2 cells where CTRP3 and LAMP1 promote proliferation and inhibit apoptosis in response to oxygen-glucose deprivation/reoxygenation treatment [111]. Moreover, there is evidence from inhibitor studies and coimmunoprecipitation experiments that CTRP3 and LAMP1 signal by JIP2/NUMB-assisted activation of cJun N-terminal kinases to protect from I/R injury [111,112]. Via its second C1q domain, which also mediates oligomerization of the molecule, CTRP4 interacts with nucleolin.…”