RESUMEN
The survival promoting peptide Y-P30 has documented neuroprotective effects as well as cell survival and neurite outgrowth promoting activity in vitro and in vivo. Previous work has shown that multimerization of the peptide with pleiotrophin (PTN) and subsequent binding to syndecan (SDC) -2 and -3 is involved in its neuritogenic effects. In this study we show that Y-P30 application regulates the nuclear localization of the SDC binding partner Calcium/calmodulin-dependent serine kinase (CASK) in neuronal primary cultures during development. In early development at day in vitro (DIV) 8 when mainly SDC-3 is expressed supplementation of the culture medium with Y-P30 reduces nuclear CASK levels whereas it has the opposite effect at DIV 18 when SDC-2 is the dominant isoform. In the nucleus CASK regulates gene expression via its association with the T-box transcription factor T-brain-1 (Tbr-1) and we indeed found that gene expression of downstream targets of this complex, like the GluN2B NMDA-receptor, exhibits a corresponding down- or up-regulation at the mRNA level. The differential effect of Y-P30 on the nuclear localization of CASK correlates with its ability to induce shedding of the ectodomain of SDC-2 but not -3. shRNA knockdown of SDC-2 at DIV 18 and SDC-3 at DIV 8 completely abolished the effect of Y-P30 supplementation on nuclear CASK levels. During early development a protein knockdown of SDC-3 also attenuated the effect of Y-P30 on axon outgrowth. Taken together these data suggest that Y-P30 can control the nuclear localization of CASK in a SDC-dependent manner.
Asunto(s)
Guanilato-Quinasas/metabolismo , Péptidos/metabolismo , Sindecano-2/metabolismo , Sindecano-3/metabolismo , Animales , Western Blotting , Células COS , Núcleo Celular/efectos de los fármacos , Núcleo Celular/genética , Núcleo Celular/metabolismo , Células Cultivadas , Chlorocebus aethiops , Expresión Génica/efectos de los fármacos , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Células HEK293 , Humanos , Microscopía Fluorescente , Proteínas del Tejido Nervioso/metabolismo , Neuronas/citología , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Péptidos/farmacología , Unión Proteica , Interferencia de ARN , Ratas , Ratas Long-Evans , Receptores de N-Metil-D-Aspartato/genética , Receptores de N-Metil-D-Aspartato/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sindecano-2/genética , Sindecano-3/genética , Proteínas de Dominio T Box/metabolismo , Factores de TiempoRESUMEN
OBJECTIVE: To investigate effects of Saikosaponin D (SSd) on syndecan-2, matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases-2 (TIMP-2) in livers of rat with hepatocellular carcinoma (HCC). METHODS: Male SD rats were divided into control (n=10), model (n=20) and SSd (n=20) groups, and model and SSd groups given intragastric 0.2% (w/v) N-diethylnitrosamine to induce HCC. SSd group received 0.03% (w/v) SSd in saline. Liver samples were analysed immunohistochemically for syndecan-2, MMP-2, MMP-13 and TIMP-2 at 16 weeks. RESULTS: The model group had more malignant nodules than the SSd group; all model-group HCC cells were grade III; SSd-group HCC cells were grades I-II. Controls showed normal hepatic cell phenotypes and no syndecan-2+ staining. Syndecan-2+ staining was greater in the model group (35.2%, P < or = 0.001) than in controls or the SSd group (16.5%, P < or = 0.001). The model group had more intense MMP-2+ staining than controls (0.37 vs 0.27, P< or =0.01) or the SSd group (0.31 vs 0.37, P< or =0.05); and higher MMP-13+ staining (72.55%) than in controls (12.55%, P< or =0.001) and SSd group (20.18%, P< or =0.01). The model group also had more TIMP-2+ staining (57.2%) than controls (20.9%, P< or =0.001) and SSd group (22.7%, P< or=0.001). Controls and SSd group showed no difference in TIMP-2+ rates. CONCLUSION: SSd inhibited HCC development, and downregulated expression of syndecan-2, MMP-2, MMP-13 and TIMP-2 in rat HCC liver tissue.