NETO2 promotes melanoma progression via activation of the Ca2+/CaMKII signaling pathway / 医学前沿

Melanoma is the most aggressive cutaneous tumor. Neuropilin and tolloid-like 2 (NETO2) is closely related to tumorigenesis. However, the functional significance of NETO2 in melanoma progression remains unclear. Herein, we found that NETO2 expression was augmented in melanoma clinical tissues and associated with poor prognosis in melanoma patients. Disrupting NETO2 expression markedly inhibited melanoma proliferation, malignant growth, migration, and invasion by downregulating the levels of calcium ions (Ca2+) and the expression of key genes involved in the calcium signaling pathway. By contrast, NETO2 overexpression had the opposite effects. Importantly, pharmacological inhibition of CaMKII/CREB activity with the CaMKII inhibitor KN93 suppressed NETO2-induced proliferation and melanoma metastasis. Overall, this study uncovered the crucial role of NETO2-mediated regulation in melanoma progression, indicating that targeting NETO2 may effectively improve melanoma treatment.

Effects of CaMKII phosphorylation on myocardial ischemia-reperfusion injury in rats / 中华急诊医学杂志

Objective:To explore the effects of calcium/calmodulin dependent protein kinase II (CaMKII) on myocardial ischemia-reperfusion injury in vitro, and apoptosis and autophagy of myocardial cells in isolated rats.Methods:Seventy female SD rats (250-280 g) with normal electrocardiogram were selected to establish the myocardial IR injury model by Langendorff perfusion system. These SD rats were randomly divided into five groups (n=14): cardiac ischemia reperfusion group (IR group), CaMKII phosphorylation activator group (IR+ isoproterenol group), CaMKII phosphorylation inhibitor analogue group (IR+KN92 group), CaMKII phosphorylation inhibitor group (IR+KN93 group), and control group. After reperfusion, the left ventricular function and myocardial morphology were measured to assess the myocardial injury, and TUNEL was performed to assess the apoptosis index. Western blot was used to determine the phosphorylation levels of CaMKII and PLN (p-CaMKII/CaMKII and p-PLN/PLN), and the expression levels of apoptosis-related proteins Bax, Bcl-2, cleaved caspase-3, and autophagy marker proteins LC3II/LC3I, Beclin-1 and P62.Results:Compared with the control group, the left ventricular function of the IR group was decreased, morphological arrangement of myocardial fibers was disordered, and the apoptosis index was increased. The levels of p-CaMKII/CaMKII, p-PLN/PLN, cleaved caspase-3, Bax/Bcl-2, LC3II/LC3I, and Beclin-1 were increased significantly, while the level of P62 was decreased significantly, and apoptosis and autophagy were increased significantly (all P<0.05). Compared with the IR group, the myocardial damage of rats in the IR+KN93 group was significantly improved, the apoptosis index was decreased, and the expression of p-CaMKII/CaMKII, p-PLN/PLN, Cleaved Caspase-3, Bax/Bcl-2, LC3II/LC3I and Beclin-1 were significantly decreased and the level of p62 was remarkable increased, and apoptosis and autophagy decreased significantly (all P< 0.05). Compared with the IR group, the left ventricular function was further decreased in the IR+ isoproterenol group, while the levels of apoptosis and autophagy were further increased ( P < 0.05), while there was no significant difference in myocardial indexes between the IR+ KN92 group and the IR group ( P > 0.05). Conclusions:Inhibition of CaMKII phosphorylation attenuates isolated myocardial ischemia-reperfusion injury by reducing apoptosis and autophagy.

Targeting redox-altered plasticity to reactivate synaptic function: A novel therapeutic strategy for cognitive disorder

Redox-altered plasticity refers to redox-dependent reversible changes in synaptic plasticity

CaMKII-smad1 promotes axonal regeneration of peripheral nerves / 中国组织工程研究

BACKGROUND: Axons do not regenerate after central nervous system injury in mammals. It is mainly caused by the inhibitory microenvironment at the site of damage and the weakened self-regeneration ability. Studies have found that peripheral nervous system has certain regeneration ability after injury, so we explore the methods of central nervous system repair by studying the genes promoting peripheral nervous system regeneration. As one of the important protein kinase families of neurons, CaMKII up-regulation can improve the ability of neuron regeneration. Similarly, acute depletion of the Smad1 protein in adult mice also prevented axon regeneration in vivo. These genes can directly or indirectly regulate neuronal axon regeneration, but exactly how they regulate neuronal regeneration is still unclear. OBJECTIVE: To study the effects of CaMKII-Smad1 signaling pathway on axon regeneration of dorsal root ganglion neurons by intraperitoneal injection of CaMKII inhibitor and activator, and explored the mechanism of CaMKII and Smad1 in regulating axon regeneration of dorsal root ganglion neurons. METHODS: Totally 40 ICR mice were randomly divided into four groups: KN93 control group, KN93 experimental group, CdCl2 control group and CdCl2 experimental group. Dorsal root ganglion tissue was taken for in vitro culture after 7 days of continuous administration of CaMKII inhibitor KN93 and activator CdCl2. The length of axonal regeneration of dorsal root ganglion neurons was statistically analyzed after 3 days. Protein expression of p-Smad1 in dorsal root ganglion neurons was detected using western blot assay. RESULTS AND CONCLUSION: (1) Compared with the KN93 control group, axonal regeneration of dorsal root ganglion neurons was inhibited, and the p-Smad1 protein expression was decreased in the KN93 experimental group, showing significant differences. (2) Compared with the CdCl2 control group, axonal regeneration of dorsal root ganglion neurons was promoted, and p-Smad1 protein expression was increased in the CdCl2 experimental group, showing significant differences. (3) The results showed that the CaMKII-Smad1 signaling pathway had a regulatory effect on axonal regeneration of dorsal root ganglion neurons.

Ca2+/Calmodulin-dependent kinase II delta B is essential for cardiomyocyte hypertrophy and complement gene expression after LPS and HSP60 stimulation in vitro

Inflammation plays an important role in the development of cardiovascular diseases (CVDs), suggesting that the immune system is a target of therapeutic interventions used for treating CVDs. This study evaluated mechanisms underlying inflammatory response and cardiomyocyte hypertrophy associated with bacterial lipopolysaccharide (LPS)- or heat shock protein 60 (HSP60)-induced Toll-like receptor (TLR) stimulation and the effect of a small interfering RNA (siRNA) against Ca2+/calmodulin-dependent kinase II delta B (CaMKIIδB) on these outcomes. Our results showed that treatment with HSP60 or LPS (TLR agonists) induced cardiomyocyte hypertrophy and complement system C3 and factor B gene expression. In vitro silencing of CaMKIIδB prevented complement gene transcription and cardiomyocyte hypertrophy associated with TLR 2/4 activation but did not prevent the increase in interleukin-6 and tumor necrosis factor-alfa gene expression in primary cultured cardiomyocytes. Moreover, CaMKIIδB silencing attenuated nuclear factor-kappa B expression. These findings supported the hypothesis that CaMKIIδB acts as a link between inflammation and cardiac hypertrophy. Furthermore, the present study is the first to show that extracellular HSP60 activated complement gene expression through CaMKIIδB. Our results indicated that a stress stimulus induced by LPS or HSP60 treatment promoted cardiomyocyte hypertrophy and initiated an inflammatory response through the complement system. However, CaMKIIδB silencing prevented the cardiomyocyte hypertrophy independent of inflammatory response induced by LPS or HSP60 treatment.

Research progress of RNA-binding motif protein 20 in cardiomyopathy / 中国药理学通报

Cardiomyopathy is a heterogeneous heart disease characterized by abnormalities in myocardial structure and function, which ultimately leads to heart failure even death. RNA-binding motif protein 20 (RBM 20) is a family of serine/arginine-rich proteins, highly expressed in heart. It plays an important role in the assembly and alternative splicing of RNA spliceosome, and participates in the development of cardiomyopathy. RBM 20 regulates the alternative splicing of Titin, RyR 2, LDB 3, CaMKIIô, CACNA1C involved in diastolic function, sarcomere assembly and ion transport. In this review, the role of RBM 20 in cardiomyopathy and the regulatory mechanisms of RBM 20 is summarized.

A study on mechanisms of CaMKII mediated 20-HETE-induced apoptosis in neonatal rat cardiomyocytes / 实用医学杂志

Objective To study the effect of 20-HETE on apoptosis in cultured neonatal rat cardiomyo-cytes and investigate its mechanism. Methods Neonatal rat cardiomyocytes were cultured in vitro.CCK-8 method was used to detect the cell activity and TUNEL assay was performed to analyze the cell apoptosis. Flou-3/AM la-belled assay was applied to measure the concentration of intracellular calcium([Ca2+]i). Western blot was per-formed to measure the expressions of RyR2,SERCA2a,CaMKII and phospho-CaMKII. Results Treatment with 20-HETE reduced the activity of cardiomyocytes and induced cell apoptosis obviously,while KN-93,an inhibitor of CaMKII,blocked the effects of 20-HETE. Treatment with 20-HETE significantly increased cardiomyocytes [Ca2+]i,up-regulated the expression of RyR2,and down-regulated the expression of SERCA2a,which could be blocked by KN-93. 20-HETE also increased the expressions of CaMKII and phospho-CaMKII in cardiomyocytes, indicating 20-HETE played a role in activating the CaMKII signaling pathway. Conclusions 20-HETE leads to altered functions of cardiac sarcoplasmic reticulum calcium-transport protein RyR2 and SERCA2a via activating the CaMKII signaling pathway,which causes calcium overload and induces apoptosis in neonatal rat cardiomyocytes.

Protective effects of kaempferol against cardiac sinus node dysfunction via CaMKII deoxidization / 대한해부학회지

Kaempferol exerts cardioprotective actions through incompletely understood mechanisms. This study investigated the molecular mechanisms underlying the cardioprotective effects of kaempferol in sinus node dysfunction (SND) heart. Here, we demonstrate that angiotensin II (Ang II) infusion causes SND through oxidized calmodulin kinase II (CaMKII). In contrast to this, kaempferol protects sinus node against Ang II-induced SND. Ang II evoked apoptosis with caspase-3 activation in sinus nodal cells. However, kaempferol lowered the CaMKII oxidization and the sinus nodal cell death. To block the CaMKII oxidization, gene of p47phox, a cytosolic subunit of NADPH oxidase, was deleted using Cas9 KO plasmid. In the absence of p47phox, sinus nodal cells were highly resistance to Ang II-induced apoptosis, suggesting that oxidized-CaMKII contributed to sinus nodal cell death. In Langendorff heart from Ang II infused mice, kaempferol preserved normal impulse formation at right atrium. These data suggested that kaempferol protects sinus node via inhibition of CaMKII oxidization and may be useful for preventing SND in high risk patients.

Simultaneous deletion of floxed genes mediated by CaMKIIalpha-Cre in the brain and in male germ cells: application to conditional and conventional disruption of Goalpha

The Cre/LoxP system is a well-established approach to spatially and temporally control genetic inactivation. The calcium/calmodulin-dependent protein kinase II alpha subunit (CaMKIIalpha) promoter limits expression to specific regions of the forebrain and thus has been utilized for the brain-specific inactivation of the genes. Here, we show that CaMKIIalpha-Cre can be utilized for simultaneous inactivation of genes in the adult brain and in male germ cells. Double transgenic Rosa26(+/stop-lacZ)::CaMKIIalpha-Cre(+/Cre) mice generated by crossing CaMKIIalpha-Cre(+/Cre) mice with floxed ROSA26 lacZ reporter (Rosa26(+/stop-lacZ)) mice exhibited lacZ expression in the brain and testis. When these mice were mated to wild-type females, about 27% of the offspring were whole body blue by X-gal staining without inheriting the Cre transgene. These results indicate that recombination can occur in the germ cells of male Rosa26(+/stop-lacZ)::CaMKIIalpha-Cre(+/Cre) mice. Similarly, when double transgenic Gnao(+/f)::CaMKIIalpha-Cre(+/Cre) mice carrying a floxed Go-alpha gene (Gnao(f/f)) were backcrossed to wild-type females, approximately 22% of the offspring carried the disrupted allele (Gnao(Delta)) without inheriting the Cre transgene. The Gnao(Delta/Delta) mice closely resembled conventional Go-alpha knockout mice (Gnao(-/-)) with respect to impairment of their behavior. Thus, we conclude that CaMKIIalpha-Cre mice afford recombination for both tissue- and time-controlled inactivation of floxed target genes in the brain and for their permanent disruption. This work also emphasizes that extra caution should be exercised in utilizing CaMKIIalpha-Cre mice as breeding pairs.

CaMKII Inhibitor KN-62 Blunts Tumor Response to Hypoxia by Inhibiting HIF-1alpha in Hepatoma Cells

In rapidly growing tumors, hypoxia commonly develops due to the imbalance between O2 consumption and supply. Hypoxia Inducible Factor (HIF)-1alpha is a transcription factor responsible for tumor growth and angiogenesis in the hypoxic microenvironment; thus, its inhibition is regarded as a promising strategy for cancer therapy. Given that CamKII or PARP inhibitors are emerging anticancer agents, we investigated if they have the potential to be developed as new HIF-1alpha-targeting drugs. When treating various cancer cells with the inhibitors, we found that a CamKII inhibitor, KN-62, effectively suppressed HIF-1alpha specifically in hepatoma cells. To examine the effect of KN-62 on HIF-1alpha-driven gene expression, we analyzed the EPO-enhancer reporter activity and mRNA levels of HIF-1alpha downstream genes, such as EPO, LOX and CA9. Both the reporter activity and the mRNA expression were repressed by KN-62. We also found that KN-62 suppressed HIF-1alpha by impairing synthesis of HIF-1alpha protein. Based on these results, we propose that KN-62 is a candidate as a HIF-1alpha-targeting anticancer agent.

Effect and potential mechanism of replenishing the kidney and eliminating phlegm therapy on CaMKⅡ-? activities of AD rat model / 中华中医药杂志

Objective:To observe the effect of replenishing the kidney and eliminating phlegm therapy on calciumlcalmodulin-dependent protein kinase Ⅱ(CaMKⅡ-?) activities of AD rat model,and explore the potential mechanism.Methods:AD model was established by injection of ibotenic acid(IBO) and 25-35 ?-amyloid peptide(A?25-35) into basal nucleus of Meynert.After injecting for two weeks,Bushen Huatan Decoction was administered by oral gavage of high,middle and low dosages.Huperzine A-Zhulin Antun tablets served as control drug.Normal group,model group and blank group were administered with isovolumetric saline water.After treating for four weeks,hybridization in situ was used to observe the change of CaMK Ⅱ in hippocamp.Results:The expression of CaMKⅡ-? in model group was more than that in normal group(P