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The regenerative functions associated with cytokines and growth factors have immense therapeutic potential; however, their poor pharmacokinetics, resulting from structural features, hinder their effectiveness. In this study, we aimed to enhance the pharmacokinetics of growth factors by designing receptor-binding macrocyclic peptides through in vitro mRNA display and grafting them into loops of immunoglobulin's crystallizable region (Fc). As a model, we developed peptide-grafted Fc proteins with hepatocyte growth factor (HGF) functionality that exhibited a prolonged circulation half-life and could be administered subcutaneously. The Fc-based HGF mimetic alleviated liver fibrosis in a mouse model fed a choline-deficient high-fat diet, which induces hepatic features of non-alcoholic steatohepatitis, including fibrosis, showcasing its potential as a therapeutic intervention. This study provides a basis for developing growth factor and cytokine mimetics with improved pharmacokinetics, expanding their therapeutic applications.
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Epithelial tissue is at the forefront of innate immunity, playing a crucial role in the recognition and elimination of pathogens. Met is a receptor tyrosine kinase that is necessary for epithelial cell survival, proliferation, and regeneration. Here, we showed that Met is essential for the induction of cytokine production by cytosolic nonself double-stranded RNA through retinoic acid-inducible gene-I-like receptors (RLRs) in epithelial cells. Surprisingly, the tyrosine kinase activity of Met was dispensable for promoting cytokine production. Rather, the intracellular carboxy terminus of Met interacted with mitochondrial antiviral-signaling protein (MAVS) in RLR-mediated signaling to directly promote MAVS signalosome formation. These studies revealed a kinase activity-independent function of Met in the promotion of antiviral innate immune responses, defining dual roles of Met in both regeneration and immune responses in the epithelium.
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Células Epiteliales , Proteínas Tirosina Quinasas Receptoras , Inmunidad Innata , Antivirales , CitocinasRESUMEN
A fetal pituitary hormone, oxytocin which causes uterine contractions, increases throughout gestation, and its increase reaches 10-fold from week 32 afterward. Oxytocin is, on the other hand, degraded by placental leucine aminopeptidase (P-LAP) which exists in both terminal villi and maternal blood. Maternal blood P-LAP increases with advancing gestation under the control of non-genomic effects of progesterone, which is also produced from the placenta. Progesterone is converted to estrogen by CYP17A1 localized in the fetal adrenal gland and placenta at term. The higher oxytocin concentrations in the fetus than in the mother demonstrate not only fetal oxytocin production but also its degradation and/or inhibition of leakage from fetus to mother by P-LAP. Until labor onset, the pregnant uterus is quiescent possibly due to the balance between increasing fetal oxytocin and P-LAP under control of progesterone. A close correlation exists between the feto-placental and maternal units in the placental circulation, although the blood in the two circulations does not necessarily mix. Fetal maturation results in progesterone withdrawal via the CYP17A1 activation accompanied with fetal oxytocin increase. Contribution of fetal oxytocin to labor onset has been acknowledged through the recognition that the effect of fetal oxytocin in the maternal blood is strictly regulated by its degradation by P-LAP under the control of non-genomic effects of progesterone. In all senses, the fetus necessarily takes the initiative in labor onset.
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Rho in filopodia (Rif), a member of the Rho family of small GTPases, induces filopodia formation primarily on the dorsal surface of cells; however, its function remains largely unclear. Here, we show that Rif interacts with Ror1, a receptor for Wnt5a that can also induce dorsal filopodia. Our immunohistochemical analysis revealed a high frequency of coexpression of Ror1 and Rif in lung adenocarcinoma. Lung adenocarcinoma cells cultured on Matrigel established front-rear polarity with massive filopodia on their front surfaces, where Ror1 and Rif were accumulated. Suppression of Ror1 or Rif expression inhibited cell proliferation, survival, and invasion, accompanied by the loss of filopodia and cell polarity in vitro, and prevented tumor growth in vivo. Furthermore, we found that Rif was required to activate Wnt5a-Ror1 signaling at the cell surface leading to phosphorylation of the Wnt signaling pathway hub protein Dvl2, which was further promoted by culturing the cells on Matrigel. Our findings reveal a novel function of Rif in mediating Wnt5a-Ror1-Dvl2 signaling, which is associated with the formation of polarized filopodia on 3D matrices in lung adenocarcinoma cells.
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Receptor tyrosine kinases (RTKs) are generally activated through their dimerization and/or oligomerization induced by their cognate ligands, and one such RTK hepatocyte growth factor (HGF) receptor, known as MET, plays an important role in tissue regeneration. Here we show the development of ubiquitin (Ub)-based protein ligand multimers, referred to as U-bodies, which act as surrogate agonists for MET and are derived from MET-binding macrocyclic peptides. Monomeric Ub constructs (U-body) were first generated by genetic implantation of a macrocyclic peptide pharmacophore into a structural loop of Ub (lasso-grafting) and subsequent optimization of its flanking spacer sequences via mRNA display. Such U-body constructs exhibit potent binding affinity to MET, thermal stability, and proteolytic stability. The U-body constructs also partially/fully inhibited or enhanced HGF-induced MET-phosphorylation. Their multimerization to dimeric, tetrameric, and octameric U-bodies linked by an appropriate peptide linker yielded potent MET activation activity and downstream cell proliferation-promoting activity. This work suggests that lasso-grafting of macrocycles to Ub is an effective approach to devising protein-based artificial RTK agonists and it can be useful in the development of a new class of biologics for various therapeutic applications.
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Factor de Crecimiento de Hepatocito , Ubiquitina , Factor de Crecimiento de Hepatocito/metabolismo , Ubiquitina/metabolismo , Unión Proteica , Proteínas Proto-Oncogénicas c-met/metabolismo , Fosforilación , Péptidos/farmacología , Péptidos/metabolismoRESUMEN
Two-chain hepatocyte growth factor (tcHGF), the mature form of HGF, is associated with malignancy and anticancer drug resistance; therefore, its quantification is an important indicator for cancer diagnosis. In tumors, activated tcHGF hardly discharges into the systemic circulation, indicating that tcHGF is an excellent target for molecular imaging using positron emission tomography (PET). We recently discovered HGF-inhibitory peptide-8 (HiP-8) that binds specifically to human tcHGF with nanomolar affinity. The purpose of this study was to investigate the usefulness of HiP-8-based PET probes in human HGF knock-in humanized mice. 64Cu-labeled HiP-8 molecules were synthesized using a cross-bridged cyclam chelator, CB-TE1K1P. Radio-high-performance liquid chromatography-based metabolic stability analyses showed that more than 90% of the probes existed in intact form in blood at least for 15 min. In PET studies, significantly selective visualization of hHGF-overexpressing tumors versus hHGF-negative tumors was observed in double-tumor-bearing mice. The accumulation of labeled HiP-8 into the hHGF-overexpressing tumors was significantly reduced by competitive inhibition. In addition, the radioactivity and distribution of phosphorylated MET/HGF receptor were colocalized in tissues. These results demonstrate that the 64Cu-labeled HiP-8 probes are suitable for tcHGF imaging in vivo, and secretory proteins like tcHGF can be a target for PET imaging.
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Factor de Crecimiento de Hepatocito , Neoplasias , Ratones , Humanos , Animales , Factor de Crecimiento de Hepatocito/metabolismo , Péptidos/química , Neoplasias/diagnóstico por imagen , Tomografía de Emisión de Positrones/métodos , Quelantes/química , Radioisótopos de Cobre/química , Línea Celular TumoralRESUMEN
BACKGROUND: Entrectinib is an effective drug for treating solid tumors with NTRK gene rearrangement and non-small cell lung cancer (NSCLC) with ROS1 gene rearrangement. However, its efficacy is limited by tolerance and acquired resistance, the mechanisms of which are not fully understood. The growth factors produced by the tumor microenvironment, including hepatocyte growth factor (HGF) produced by tumor-associated fibroblasts, critically affect the sensitivity to targeted drugs. METHODS: We investigated whether growth factors that can be produced by the microenvironment affect sensitivity of NTRK1-rearranged colon cancer KM12SM cells and ROS1-rearranged NSCLC HCC78 cells to entrectinib both in vitro and in vivo. RESULTS: Among the growth factors assessed, HGF most potently induced entrectinib resistance in KM12SM and HCC78 cells by activating its receptor MET. HGF-induced entrectinib resistance was reversed by the active-HGF-specific macrocyclic peptide HiP-8 and the MET kinase inhibitor capmatinib in vitro. In addition, HGF-producing fibroblasts promoted entrectinib resistance in vitro (culture model) and in vivo (subcutaneous tumor model). The use of capmatinib circumvented entrectinib resistance in a subcutaneous tumor model inoculated with KM12SM and HGF-producing fibroblasts. CONCLUSION: Our findings suggest that growth factors in the tumor microenvironment, such as HGF, may induce resistance to entrectinib in tumors with NTRK1 or ROS1 rearrangements. Our results further suggest that optimally co-administering inhibitors of resistance-inducing growth factors may maximize the therapeutic efficacy of entrectinib.
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Antineoplásicos , Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Humanos , Antineoplásicos/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Factor de Crecimiento de Hepatocito/genética , Factor de Crecimiento de Hepatocito/farmacología , Neoplasias Pulmonares/patología , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Tirosina Quinasas/genética , Proteínas Proto-Oncogénicas/genética , Proteínas Tirosina Quinasas Receptoras , Microambiente TumoralRESUMEN
Short half-lives in circulation and poor transport across the blood-brain barrier limit the utility of cytokines and growth factors acting as receptor agonists. Here we show that surrogate receptor agonists with longer half-lives in circulation and enhanced transport rates across the blood-brain barrier can be generated by genetically inserting macrocyclic peptide pharmacophores into the structural loops of the fragment crystallizable (Fc) region of a human immunoglobulin. We used such 'lasso-grafting' approach, which preserves the expression levels of the Fc region and its affinity for the neonatal Fc receptor, to generate Fc-based protein scaffolds with macrocyclic peptides binding to the receptor tyrosine protein kinase Met. The Met agonists dimerized Met, inducing biological responses that were similar to those induced by its natural ligand. Moreover, lasso-grafting of the Fc region of the mouse anti-transferrin-receptor antibody with Met-binding macrocyclic peptides enhanced the accumulation of the resulting Met agonists in brain parenchyma in mice. Lasso-grafting may allow for designer protein therapeutics with enhanced stability and pharmacokinetics.
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Barrera Hematoencefálica , Péptidos , Humanos , Animales , Ratones , Encéfalo , Citocinas , SemividaRESUMEN
Ubiquitin-proteasome dysfunction contributes to obesity-related metabolic disorders, such as diabetes and fatty liver disease. However, the regulation of ubiquitin-proteasome activity by insulin remains to be elucidated. Here, we show that prolonged insulin stimulation activates proteasome function even though it reduces the ubiquitinated proteins in H4IIEC3 hepatocytes. Looking for a pathway by which insulin inhibits ubiquitination, we found that hepatic expression of ubiquitin-specific protease 14 (USP14) was upregulated in the liver of patients with insulin resistance. Indeed, the USP14-specific inhibitor IU1 canceled the insulin-mediated reduction of ubiquitinated proteins. Furthermore, insulin-induced endoplasmic reticulum (ER) stress, which was canceled by IU1, suggesting that USP14 activity is involved in insulin-induced ER stress. Co-stimulation with insulin and IU1 for 2 hours upregulated the nuclear translocation of the lipogenic transcription factor, sterol regulatory element binding protein-1c (SREBP-1c), upregulated the expression of the lipogenic gene, fatty acid synthase (Fasn), and repressed the gluconeogenic genes. In conclusion, insulin activates proteasome function even though it inhibits protein ubiquitination by activating USP14 in hepatocytes. USP14 activation by insulin inhibits mature SREBP-1c while upregulating ER stress and the expression of genes involved in gluconeogenesis. Further understanding mechanisms underlying the USP14 activation and its pleiotropic effects may lead to therapeutic development for obesity-associated metabolic disorders, such as diabetes and fatty liver disease. SIGNIFICANCE STATEMENT: This study shows that insulin stimulation inhibits ubiquitination by activating USP14, independent of its effect on proteasome activity in hepatocytes. USP14 also downregulates the nuclear translocation of the lipogenic transcription factor SREBP-1c and upregulates the expression of genes involved in gluconeogenesis. Since USP14 is upregulated in the liver of insulin-resistant patients, understanding mechanisms underlying the USP14 activation and its pleiotropic effects will help develop treatments for metabolic disorders such as diabetes and fatty liver.
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Hepatocitos , Enfermedad del Hígado Graso no Alcohólico , Complejo de la Endopetidasa Proteasomal , Proteína 1 de Unión a los Elementos Reguladores de Esteroles , Humanos , Enzimas Desubicuitinizantes/genética , Enzimas Desubicuitinizantes/metabolismo , Diabetes Mellitus/genética , Diabetes Mellitus/metabolismo , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Insulina/farmacología , Insulina/metabolismo , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Obesidad/genética , Obesidad/metabolismo , Complejo de la Endopetidasa Proteasomal/genética , Complejo de la Endopetidasa Proteasomal/metabolismo , Complejo de la Endopetidasa Proteasomal/farmacología , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/genética , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/metabolismo , Ubiquitina Tiolesterasa/genética , Ubiquitina Tiolesterasa/metabolismo , Proteasas Ubiquitina-Específicas/genética , Proteasas Ubiquitina-Específicas/metabolismo , Proteasas Ubiquitina-Específicas/farmacología , Proteínas Ubiquitinadas/genética , Proteínas Ubiquitinadas/metabolismo , Proteínas Ubiquitinadas/farmacología , Ubiquitinación , Ubiquitinas/genética , Ubiquitinas/metabolismo , Ubiquitinas/farmacologíaRESUMEN
Retinoic acid-inducible gene (RIG)-I is an essential innate immune sensor that recognises pathogen RNAs and induces interferon (IFN) production. However, little is known about how host proteins regulate RIG-I activation. Here, we show that leukocyte cell-derived chemotaxin 2 (LECT2), a hepatokine and ligand of the MET receptor tyrosine kinase is an antiviral regulator that promotes the RIG-I-mediated innate immune response. Upon binding to MET, LECT2 induces the recruitment of the phosphatase PTP4A1 to MET and facilitates the dissociation and dephosphorylation of phosphorylated SHP2 from MET, thereby protecting RIG-I from SHP2/c-Cbl-mediated degradation. In vivo, LECT2 overexpression enhances RIG-I-dependent IFN production and inhibits lymphocytic choriomeningitis virus (LCMV) replication in the liver, whereas these changes are reversed in LECT2 knockout mice. Forced suppression of MET abolishes IFN production and antiviral activity in vitro and in vivo. Interestingly, hepatocyte growth factor (HGF), an original MET ligand, inhibits LECT2-mediated anti-viral signalling; conversely, LECT2-MET signalling competes with HGF-MET signalling. Our findings reveal previously unrecognized crosstalk between MET-mediated proliferation and innate immunity and suggest that targeting LECT2 may have therapeutic value in infectious diseases and cancer.
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Factores de Restricción Antivirales , Péptidos y Proteínas de Señalización Intercelular , Proteínas Proto-Oncogénicas c-met , Animales , Factores de Restricción Antivirales/inmunología , Inmunidad Innata , Péptidos y Proteínas de Señalización Intercelular/inmunología , Leucocitos/metabolismo , Ligandos , Ratones , Proteínas Proto-Oncogénicas c-met/metabolismoRESUMEN
In pregnancy, placental circulation occurs through two independent circulation systems: foetoplacental and uterine (spiral artery)-placental lake. Crosstalk between the foetal peptide hormones, angiotensin II (A-II) and vasopressin (AVP), and their degrading placental aminopeptidases (APs), aminopeptidase A for A-II and placental leucine aminopeptidase for both AVP and oxytocin, primarily regulate placental circulation. On the other hand, placental circulation represents an arteriovenous shunt. In normal pregnancy, the blood pressure decreases, despite increased cardiac output and plasma volume, probably due to the arteriovenous shunt in the growing placenta. Actually, the foetal vasoactive hormones in the foetoplacental circulation are much higher than those in the maternal circulation throughout pregnancy. In normal pregnancy, AP activity derived from the placenta in maternal blood increases with gestation and placental growth. Foetal hypoxia increases the secretion of foetal both AVP and A-II. Although there is an increase in both AP activities in the maternal blood in normal pregnancy, their activities increase more than those in normal pregnancy during mild preeclampsia. However, both AP activities decline significantly compared than those in severe preeclampsia. This suggests that AP prevents leakage of increased foetal vasoactive hormones into the maternal blood in mild preeclampsia, and its protective role breaks down in severe preeclampsia, leading to a massive leak of the hormones into maternal circulation and consequent marked contraction of both the maternal vessels and the uterus. Consequently, AP activity in both placenta and maternal blood acts as the foeto-maternal barrier for foetal vasoactive hormones and thus contributes to the onset of preeclampsia.
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Hormonas Peptídicas , Preeclampsia , Cistinil Aminopeptidasa/fisiología , Femenino , Hormonas , Humanos , Placenta , Circulación Placentaria , EmbarazoRESUMEN
Scirrhous gastric cancer frequently develops into peritoneal carcinomatosis with malignant ascites, leading to an extremely poor prognosis. We had demonstrated that paracrine hepatocyte growth factor (HGF)-induced MET activation promotes peritoneal carcinomatosis with ascites formation. The vascular endothelial growth factor (VEGF) receptor (VEGFR)/VEGF axis facilitates tumor progression and formation of malignant ascites. This study investigated the role of MET and VEGFR2 in the development of peritoneal carcinomatosis with malignant ascites. Cabozantinib is a dual inhibitor of MET and VEGFR2. We examined the effects of cabozantinib on MET- and VEGFR2-mediated progression of peritoneal carcinomatosis in human scirrhous gastric cancer in vitro and in vivo. Cabozantinib inhibited HGF-stimulated proliferation of scirrhous cancer cell lines NUGC4 and GCIY, with a high potential to generate peritoneal carcinomatosis with ascites fluid, as well as the constitutive proliferation of MKN45 cells with MET amplification. Cabozantinib also inhibited the phosphorylation of both MET and VEGFR2 in scirrhous cancer cells and HGF- or VEGF-stimulated HUVECs. It effectively reduced ascitic fluid and prolonged the survival of NUGC4-inoculated nude mice. In clinical specimens, malignant ascites fluid from patients with peritoneal carcinomatosis contained high levels of HGF and VEGF. Our results strongly suggest that MET- and VEGFR2-mediated signaling pathways play pivotal roles in the pathogenesis of peritoneal carcinomatosis in scirrhous gastric cancer. Thus, the dual blockade of MET and VEGFR2 signaling may be a potential therapeutic maneuver for peritoneal carcinomatosis in scirrhous gastric cancer.
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Anilidas , Neoplasias Peritoneales , Proteínas Proto-Oncogénicas c-met , Piridinas , Neoplasias Gástricas , Receptor 2 de Factores de Crecimiento Endotelial Vascular , Anilidas/farmacología , Animales , Ascitis/tratamiento farmacológico , Línea Celular Tumoral , Humanos , Ratones , Ratones Desnudos , Neoplasias Peritoneales/tratamiento farmacológico , Neoplasias Peritoneales/metabolismo , Neoplasias Peritoneales/patología , Proteínas Proto-Oncogénicas c-met/antagonistas & inhibidores , Piridinas/farmacología , Transducción de Señal/efectos de los fármacos , Neoplasias Gástricas/tratamiento farmacológico , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patología , Receptor 2 de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidoresRESUMEN
Cancer invasion and metastasis are the major causes of cancer patient mortality. Various growth factors, including hepatocyte growth factor (HGF), are known to promote cancer invasion and metastasis, but the regulatory mechanisms involved are not fully understood. Here, we show that HGF-promoted migration and invasion of breast cancer cells are regulated by CUB domain-containing protein 1 (CDCP1), a transmembrane activator of SRC kinase. In metastatic human breast cancer cell line MDA-MB-231, which highly expresses the HGF receptor MET and CDCP1, we show that CDCP1 knockdown attenuated HGF-induced MET activation, followed by suppression of lamellipodia formation and cell migration/invasion. In contrast, in the low invasive/nonmetastatic breast cancer cell line T47D, which had no detectable MET and CDCP1 expression, ectopic MET expression stimulated the HGF-dependent activation of invasive activity, and concomitant CDCP1 expression activated SRC and further promoted invasive activity. In these cells, CDCP1 expression dramatically activated HGF-induced membrane remodeling, which was accompanied by activation of the small GTPase Rac1. Analysis of guanine nucleotide exchange factors revealed that ARHGEF7 was specifically required for CDCP1-dependent induction of HGF-induced invasive ability. Furthermore, immunofluorescence staining demonstrated that CDCP1 coaccumulated with ARHGEF7. Finally, we confirmed that the CDCP1-SRC axis was also crucial for HGF and ARHGEF7-RAC1 signaling in MDA-MB-231 cells. Altogether, these results demonstrate that the CDCP1-SRC-ARHGEF7-RAC1 pathway plays an important role in the HGF-induced invasion of a subset of breast cancer cells.
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Antígenos de Neoplasias , Neoplasias de la Mama , Factor de Crecimiento de Hepatocito , Factores de Intercambio de Guanina Nucleótido Rho , Familia-src Quinasas , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/metabolismo , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Moléculas de Adhesión Celular , Línea Celular Tumoral , Movimiento Celular/fisiología , Femenino , Factor de Crecimiento de Hepatocito/metabolismo , Humanos , Invasividad Neoplásica , Proteínas Proto-Oncogénicas c-met/genética , Proteínas Proto-Oncogénicas c-met/metabolismo , Factores de Intercambio de Guanina Nucleótido Rho/genética , Factores de Intercambio de Guanina Nucleótido Rho/metabolismo , Transducción de Señal , Familia-src Quinasas/genética , Familia-src Quinasas/metabolismoRESUMEN
MET, the receptor for the hepatocyte growth factor (HGF), is strongly associated with resistance to tyrosine kinase inhibitors, key drugs that are used in the therapy of non-small cell lung cancer. MET contains 11 potential N-glycosylation sites, but the site-specific roles of these N-glycans have not been elucidated. We report herein that these N-glycans regulate the proteolytic processing of MET and HGF-induced MET signaling, and that this regulation is site specific. Inhibitors of N-glycosylation were found to suppress the processing and trafficking of endogenous MET in H1975 and EBC-1 lung cancer cells and exogenous MET in CHO-K1 cells. We purified the recombinant extracellular domain of human MET and determined the site-specific N-glycan structures and occupancy using mass spectrometry. The results indicated that most sites were fully glycosylated and that the dominant population was the complex type. To examine the effects of the deletion of N-glycans of MET, we prepared endogenous MET knockout Flp-In CHO cells and transfected them with a series of N-glycan-deletion mutants of MET. The results showed that several N-glycans are implicated in the processing of MET. The findings also suggested that the N-glycans of the SEMA domain of MET positively regulate HGF signaling, and the N-glycans of the region other than the SEMA domain negatively regulate HGF signaling. Processing, cell surface expression, and signaling were significantly suppressed in the case of the all-N-glycan-deletion mutant. The overall findings suggest that N-glycans of MET affect the status and the function of the receptor in a site-specific manner.
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Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Animales , Cricetinae , Cricetulus , Glicosilación , Factor de Crecimiento de Hepatocito/metabolismo , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Proteínas Proto-Oncogénicas c-metRESUMEN
Blastocyst implantation involves multiple interactions with numerous molecules expressed in endometrial epithelial cells (EECs) during the implantation window; however, there is limited information regarding the molecular mechanism underlying the crosstalk. In blastocysts, fibronectin plays a major role in the adhesion of various types of cells by binding to extracellular matrix proteins via the Arg-Gly-Asp (RGD) motif. In EECs, RGD-recognizing integrins are important bridging receptors for fibronectin, whereas the non-RGD binding of fibronectin includes interactions with dipeptidyl peptidase IV (DPPIV)/cluster of differentiation (CD) 26. Fibronectin may also bind to aminopeptidase N (APN)/CD13, and in the endometrium, these peptidases are present in plasma membranes and lysosomal membranes. Blastocyst implantation is accompanied by lysosome exocytosis, which transports various peptidases and nutrients into the endometrial cavity to facilitate blastocyst implantation. Both DPPIV and APN are released into the uterine cavity via shedding of microvesicles (MVs) from EECs. Recently, extracellular vesicles derived from endometrial cells have been proposed to act on trophectoderm cells to promote implantation. MVs are also secreted from embryonal stem cells and may play an active role in implantation. Thus, crosstalk between the blastocyst and endometrium via extracellular vesicles is a new insight into the fundamental molecular basis of blastocyst implantation.
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Blastocisto/metabolismo , Implantación del Embrión/fisiología , Péptido Hidrolasas/metabolismo , Adhesión Celular , Membrana Celular/metabolismo , Micropartículas Derivadas de Células/fisiología , Dipeptidil Peptidasa 4/metabolismo , Transferencia de Embrión/métodos , Endometrio/metabolismo , Endometrio/fisiología , Células Epiteliales/metabolismo , Proteínas de la Matriz Extracelular/metabolismo , Vesículas Extracelulares/metabolismo , Femenino , Fibronectinas/metabolismo , Humanos , Integrinas/metabolismo , Lisosomas/metabolismo , Útero/metabolismoRESUMEN
Fast and selective recognition of molecules at the nanometer scale without labeling is a much desired but still challenging goal to achieve. Here, we show the use of high-speed atomic force microscopy (HS-AFM) for real-time and real-space recognition of unlabeled membrane receptors using tips conjugated with small synthetic macrocyclic peptides. The single-molecule recognition method is validated by experiments on the human hepatocyte growth factor receptor (hMET), which selectively binds to the macrocyclic peptide aMD4. By testing and comparing aMD4 synthesized with linkers of different lengths and rigidities, we maximize the interaction between the functionalized tip and hMET added to both a mica surface and supported lipid bilayers. Phase contrast imaging by HS-AFM enables us to discriminate nonlabeled hMET against the murine MET homologue, which does not bind to aMD4. Moreover, using ligands and linkers of small size, we achieve minimal deterioration of the spatial resolution in simultaneous topographic imaging. The versatility of macrocyclic peptides in detecting unlimited types of membrane receptors with high selectivity and the fast imaging by HS-AFM broaden the range of future applications of this method for molecular recognition without labeling.
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Compuestos Macrocíclicos/química , Péptidos/química , Proteínas Proto-Oncogénicas c-met/análisis , Silicatos de Aluminio/química , Animales , Humanos , Ligandos , Membrana Dobles de Lípidos/química , Compuestos Macrocíclicos/síntesis química , Ratones , Microscopía de Fuerza Atómica , Estructura Molecular , Nanotecnología , Imagen Óptica , Péptidos/síntesis química , Propiedades de SuperficieRESUMEN
Lasso-grafting (LG) technology is a method for generating de novo biologics (neobiologics) by genetically implanting macrocyclic peptide pharmacophores, which are selected in vitro against a protein of interest, into loops of arbitrary protein scaffolds. In this study, we have generated a neo-capsid that potently binds the hepatocyte growth factor receptor MET by LG of anti-MET peptide pharmacophores into a circularly permuted variant of Aquifex aeolicus lumazine synthase (AaLS), a self-assembling protein nanocapsule. By virtue of displaying multiple-pharmacophores on its surface, the neo-capsid can induce dimerization (or multimerization) of MET, resulting in phosphorylation and endosomal internalization of the MET-capsid complex. This work demonstrates the potential of the LG technology as a synthetic biology approach for generating capsid-based neobiologics capable of activating signaling receptors.
RESUMEN
NK1, a splicing variant of hepatocyte growth factor (HGF), binds to and activates Met receptor by forming an NK1 dimer and 2:2 complex with Met. Although the structural mechanism underlying Met activation by HGF remains incompletely resolved, it has been proposed that the NK1 dimer structure participates in this activation. We investigated the NK1 dimer interface's role in Met activation by HGF. Because N127, V140, and K144 are closely involved in the head-to-tail NK1 dimer formation, mutant NK1 proteins with replacement of these residues by alanine were prepared. In Met tyrosine phosphorylation assays, N127-NK1, V140-NK1, and K144-NK1 showed 8.3%, 23.8%, and 52.2% activity, respectively, compared with wild-type NK1. Although wild-type NK1 promoted cell migration and scattering, N127-NK1, V140-NK1, and K144-NK1 hardly or marginally promoted them, indicating loss of activity of these mutant NK1 proteins to activate Met. In contrast, mutant HGFs (N127-HGF, V140-HGF, and K144-HGF) with the same amino acid replacements as in NK1 induced Met tyrosine phosphorylation and biological responses at levels comparable to those of wild-type HGF. These results indicate that the structural basis responsible for NK1-dependent Met dimer formation and activation differs from, or is at least distinguishable from, the structural basis responsible for HGF-dependent Met activation.
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Factor de Crecimiento de Hepatocito/química , Proteínas Proto-Oncogénicas c-met/metabolismo , Animales , Sitios de Unión , Línea Celular Tumoral , Perros , Células HEK293 , Factor de Crecimiento de Hepatocito/genética , Factor de Crecimiento de Hepatocito/metabolismo , Humanos , Células de Riñón Canino Madin Darby , Mutación , Unión Proteica , Multimerización de Proteína , Proteínas Proto-Oncogénicas c-met/química , Transducción de SeñalRESUMEN
Protein engineering has great potential for devising multifunctional recombinant proteins to serve as next-generation protein therapeutics, but it often requires drastic modifications of the parental protein scaffolds e.g., additional domains at the N/C-terminus or replacement of a domain by another. A discovery platform system, called RaPID (Random non-standard Peptides Integrated Discovery) system, has enabled rapid discovery of small de novo macrocyclic peptides that bind a target protein with high binding specificity and affinity. Capitalizing on the optimized binding properties of the RaPID-derived peptides, here we show that RaPID-derived pharmacophore sequences can be readily implanted into surface-exposed loops on recombinant proteins and maintain both the parental peptide binding function(s) and the host protein function. We refer to this protein engineering method as lasso-grafting and demonstrate that it can endow specific binding capacity toward various receptors into a diverse set of scaffolds that includes IgG, serum albumin, and even capsid proteins of adeno-associated virus, enabling us to rapidly formulate and produce bi-, tri-, and even tetra-specific binder molecules.
Asunto(s)
Péptidos/química , Péptidos/farmacología , Ingeniería de Proteínas/métodos , Proteínas de la Cápside/química , Proteínas Portadoras/química , Línea Celular , Dependovirus , Humanos , Inmunoglobulina G/química , Modelos Moleculares , Albúmina Sérica/química , Bibliotecas de Moléculas PequeñasRESUMEN
Compensatory growth of organs after loss of their mass and/or function is controlled by hepatocyte growth factor (HGF), but the underlying regulatory mechanisms remain elusive. Here, we show that CUB domain-containing protein 1 (CDCP1) promotes HGF-induced compensatory renal growth. Using canine kidney cells as a model of renal tubules, we found that HGF-induced temporal up-regulation of Src activity and its scaffold protein, CDCP1, and that the ablation of CDCP1 robustly abrogated HGF-induced phenotypic changes, such as morphological changes and cell growth/proliferation. Mechanistic analyses revealed that up-regulated CDCP1 recruits Src into lipid rafts to activate STAT3 associated with the HGF receptor Met, and activated STAT3 induces the expression of matrix metalloproteinases and mitogenic factors. After unilateral nephrectomy in mice, the Met-STAT3 signaling is transiently up-regulated in the renal tubules of the remaining kidney, whereas CDCP1 ablation attenuates regenerative signaling and significantly suppresses compensatory growth. These findings demonstrate that CDCP1 plays a crucial role in controlling compensatory renal growth by focally and temporally integrating Src and Met signaling.