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1.
Mol Carcinog ; 63(2): 286-300, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37888201

RESUMO

Bladder cancer is a common kind of urinary system cancer, in which bladder urothelial carcinoma (BLCA) comprises approximately 90% of all bladder cancer types. In our previous study, we discovered KLHDC7B in urine exosomal messenger RNA (mRNA) as a prospective molecular marker for bladder cancer detection. To systematically study the role and mechanism of KLHDC7B in BLCA, we focused on the most common type of BLCA in this study. First, we used RNA sequencing to discover that KLHDC7B was considerably increased in BLCA patients' urine exosomes compared to healthy controls. Then, we validated this result in an independent cohort and identified it as an effective tool for diagnosing and distinguishing high-grade and low-grade BLCA. Finally, we studied the role and mechanism of KLHDC7B in BLCA at the cellular level, providing a functional basis for its expression as a novel laboratory diagnostic biomarker for BLCA exosomal mRNA, which has important theoretical and clinical significance.


Assuntos
Carcinoma de Células de Transição , Neoplasias da Bexiga Urinária , Humanos , Apoptose/genética , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma de Células de Transição/patologia , Proliferação de Células/genética , RNA Mensageiro/genética , Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/diagnóstico , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia
2.
Innovation (Camb) ; 5(1): 100540, 2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38144039

RESUMO

MXenes have aroused intensive enthusiasm because of their exotic properties and promising applications. However, to date, they are usually synthesized by etching technologies. Developing synthetic technologies provides more opportunities for innovation and may extend unexplored applications. Here, we report a bottom-up gas-phase synthesis of Cl-terminated MXene (Ti2CCl2). The gas-phase synthesis endows Ti2CCl2 with unique surface chemistry, high phase purity, and excellent metallic conductivity, which can be used to accelerate polysulfide conversion kinetics and dramatically prolong the cyclability of Li-S batteries. In-depth mechanistic analysis deciphers the origin of the formation of Ti2CCl2 and offers a paradigm for tuning MXene chemical vapor deposition. In brief, the gas-phase synthesis transforms the synthesis of MXenes and unlocks the hardly achieved potentials of MXenes.

3.
Front Immunol ; 14: 1292839, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37954614

RESUMO

Human epithelial growth factor receptor-2 (HER2) plays an oncogenic role in numerous tumors, including breast, gastric, and various other solid tumors. While anti-HER2 therapies are approved for the treatment of HER2-positive tumors, a necessity persists for creating novel HER2-targeted agents to resolve therapeutic resistance. Utilizing a synthetic nanobody library and affinity maturation, our study identified four anti-HER2 nanobodies that exhibited high affinity and specificity. These nanobodies recognized three distinct epitopes of HER2-ECD. Additionally, we constructed VHH-Fc and discovered that they facilitated superior internalization and showed moderate growth inhibition. Compared to the combination of trastuzumab and pertuzumab, the VHH-Fc combos or their combination with trastuzumab demonstrated greater or comparable antitumor activity in both ligand-independent and ligand-driven tumors. Most remarkably, A9B5-Fc, which targeted domain I of HER2-ECD, displayed significantly enhanced trastuzumab-synergistic antitumor efficacy compared to pertuzumab under trastuzumab-resistant conditions. Our findings offer anti-HER2 nanobodies with high affinity and non-overlapping epitope recognition. The novel nanobody-based HER2-targeted antibody, A9B5-Fc, binding to HER2-ECD I, mediates promising receptor internalization. It possesses the potential to serve as a potent synergistic partner with trastuzumab, contributing to overcoming acquired resistance.


Assuntos
Neoplasias , Anticorpos de Domínio Único , Humanos , Trastuzumab/farmacologia , Trastuzumab/uso terapêutico , Receptor ErbB-2 , Anticorpos de Domínio Único/farmacologia , Anticorpos de Domínio Único/uso terapêutico , Ligantes , Neoplasias/patologia , Epitopos
4.
Cancers (Basel) ; 15(13)2023 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-37444603

RESUMO

The persistent threat of cancer necessitates the development of improved and more efficient therapeutic strategies that limit damage to healthy tissues. Targeted alpha therapy (TαT), a novel form of radioimmuno-therapy (RIT), utilizes a targeting vehicle, commonly antibodies, to deliver high-energy, but short-range, alpha-emitting particles specifically to cancer cells, thereby reducing toxicity to surrounding normal tissues. Although full-length antibodies are often employed as targeting vehicles for TαT, their high molecular weight and the presence of an Fc-region lead to a long blood half-life, increased bone marrow toxicity, and accumulation in other tissues such as the kidney, liver, and spleen. The discovery of single-domain antibodies (sdAbs), or nanobodies, naturally occurring in camelids and sharks, has introduced a novel antigen-specific vehicle for molecular imaging and TαT. Given that nanobodies are the smallest naturally occurring antigen-binding fragments, they exhibit shorter relative blood half-lives, enhanced tumor uptake, and equivalent or superior binding affinity and specificity. Nanobody technology could provide a viable solution for the off-target toxicity observed with full-length antibody-based TαT. Notably, the pharmacokinetic properties of nanobodies align better with the decay characteristics of many short-lived α-emitting radionuclides. This review aims to encapsulate recent advancements in the use of nanobodies as a vehicle for TαT.

5.
Huan Jing Ke Xue ; 44(5): 2661-2670, 2023 May 08.
Artigo em Chinês | MEDLINE | ID: mdl-37177939

RESUMO

Excess sludge is rich in organic matter but also contains heavy metals, pathogens, and harmful substances. In this study, hydroaluminite and excess sludge were used as raw materials to reduce the risk of heavy metals leaching from sludge by coagulation and co-pyrolysis, and its phosphate adsorption characteristics were studied. The results showed that the leaching amount of Zn, Cu, Cd, and Ni in sludge biochar decreased with the increase in the hydroaluminite dosage. The sludge biochar composite (1:1HB800), prepared by co-pyrolysis of hydroaluminite and excess sludge with a mass ratio of 1:1 as well as rich in calcium and aluminum, had lowest leaching risk of heavy metals and showed the high adsorption capacity for phosphate. The process could be fitted by the Langmuir adsorption isotherm (R2=0.93), and the maximum phosphate adsorption capacity at 25℃ was 51.38 mg·g-1. The pseudo second-order kinetic model could well describe the adsorption process of 1:1HB800 for high concentration phosphate, and its adsorption rate was controlled by both surface adsorption and particle diffusion. Compared with that in the neutral solution, 1:1HB800 had better phosphate capacity in the acidic and alkaline aqueous solutions, which was related to the leaching amount of calcium/aluminum in 1:1HB800 and the existence form of aluminum under the different pH conditions. FTIR, XRD, SEM, zero potential point, and Ca2+/Al3+ leaching experiments indicated that the main adsorption mechanisms for phosphate by 1:1HB800 were co-precipitation (interaction between Ca2+/Al3+ and phosphate), ligand exchange (hydroxyl), and electrostatic interaction. Therefore, 1:1HB800 can provide a feasible alternative for the removal of phosphate in aqueous solutions and also provide a potential new method for the resource utilization and harmless treatment of excess sludge.

7.
Pharmacol Ther ; 239: 108296, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36208791

RESUMO

Trop2 is a transmembrane glycoprotein and calcium signal transducer with limited expression in normal human tissues. It is consistently overexpressed in a variety of malignant tumors and participates in several oncogenic signaling pathways that lead to tumor development, invasion, and metastasis. As a result, Trop2 has become an attractive therapeutic target in cancer treatment. The anti-Trop2 antibody-drug conjugate (Trodelvy™, sacituzumab govitecan) has been approved to treat metastatic triple-negative breast cancer. However, it is still unclear whether the success observed in Trop2-positive breast cancer could be replicated in other tumor types, owing to the differences in the expression levels and functions of Trop2 across cancer types. In this review, we summarize the recent progress on the structures and functions of Trop2 and highlight the potential diagnostic and therapeutic value of Trop2 beyond breast cancer. In addition, the promising novel Trop2-targeted agents in the clinic were discussed, which will likely alter the therapeutic landscape of Trop2-positive tumors in the future.


Assuntos
Antineoplásicos , Neoplasias de Mama Triplo Negativas , Humanos , Antígenos de Neoplasias/metabolismo , Moléculas de Adesão Celular/metabolismo , Moléculas de Adesão Celular/uso terapêutico , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico
8.
Mol Med Rep ; 24(2)2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34080029

RESUMO

Long non­coding RNA ILF3 divergent transcript (ILF3­AS1) displays a tumor­suppressing effect. StarBase predicted that the potential target microRNA (miR) of ILF3­AS1 was miR­454­3p; therefore, the present study investigated the effect of ILF3­AS1 and its target miR­454­3p on cervical cancer (CC). Gene Expression Profiling Interactive Analysis was used to predict the expression of ILF3­AS1 in CC and the overall survival rate of patients. The present study demonstrated that ILF3­AS1 expression was significantly downregulated in human CC tissues and cells compared with adjacent tissues (ANTs) and normal cervical epithelial cells (NCEs), respectively. Patients with CC with high ILF3­AS1 expression displayed higher survival rates compared with patients with low ILF3­AS1 expression. Cell viability, apoptosis, migration and invasion were detected by performing Cell Counting Kit­8, flow cytometry, wound healing and Transwell assays, respectively. Compared with the negative control (NC) group, ILF3­AS1 overexpression significantly inhibited CC cell viability and migration, but significantly increased CC cell apoptosis. Moreover, ILF3­AS1 overexpression significantly upregulated E­Cadherin expression levels, but significantly downregulated N­Cadherin and snail family transcriptional repressor 1 expression levels compared with the NC group. miR­454­3p expression was negatively correlated with ILF3­AS1, and highly expressed in CC tissues and cells compared with ANTs and NCEs, respectively. PTEN, which was predicted and verified as the target gene for miR­454­3p, was significantly downregulated in CC tissues and cells compared with ANTs and NCEs, respectively. ILF3­AS1 expression was positively correlated with PTEN expression, and ILF3­AS1 overexpression partially reversed the inhibitory effect of miR­454­3p on PTEN expression. In conclusion, the present study indicated that ILF3­AS1 inhibited CC cell proliferation and migration, and promoted CC cell apoptosis by inhibiting epithelial­mesenchymal transition, and ILF3­AS1 overexpression partially reversed the inhibitory effect of miR­454­3p on PTEN expression.


Assuntos
Proteínas do Fator Nuclear 90/genética , Proteínas do Fator Nuclear 90/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Neoplasias do Colo do Útero/genética , Adulto , Apoptose/genética , Linhagem Celular , Movimento Celular/genética , Proliferação de Células/genética , Bases de Dados Genéticas , Regulação para Baixo/genética , Transição Epitelial-Mesenquimal/genética , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Invasividade Neoplásica/genética , PTEN Fosfo-Hidrolase/metabolismo , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/patologia
9.
Front Oncol ; 11: 667212, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33987102

RESUMO

BACKGROUND: The recent discovery of miRNAs and lncRNAs in urine exosomes has emerged as promising diagnostic biomarkers for bladder cancer (BCa). However, mRNAs as the direct products of transcription has not been well evaluated in exosomes as biomarkers for BCa diagnosis. The purpose of this study was to identify tumor progression-related mRNAs and lncRNAs in urine exosomes that could be used for detection of BCa. METHODS: RNA-sequencing was performed to identify tumor progression-related biomarkers in three matched superficial tumor and deep infiltrating tumor regions of muscle-invasive bladder cancer (MIBC) specimens, differently expressed mRNAs and lncRNAs were validated in TCGA dataset (n = 391) in the discovery stage. Then candidate RNAs were chosen for evaluation in urine exosomes of a training cohort (10 BCa and 10 healthy controls) and a validation cohort (80 BCa and 80 healthy controls) using RT-qPCR. The diagnostic potential of the candidates were evaluated by receiver operating characteristic (ROC) curves. RESULTS: RNA sequencing revealed 8 mRNAs and 32 lncRNAs that were significantly upregulated in deep infiltrating tumor region. After validation in TCGA database, 10 markedly dysregulated RNAs were selected for further investigation in urine exosomes, of which five (mRNAs: KLHDC7B, CASP14, and PRSS1; lncRNAs: MIR205HG and GAS5) were verified to be significantly dysregulated. The combination of the five RNAs had the highest AUC to disguising the BCa (0.924, 95% CI, 0.875-0.974) or early stage BCa patients (0.910, 95% CI, 0.850 to 0.971) from HCs. The expression levels of these five RNAs were correlated with tumor stage, grade, and hematuria degrees. CONCLUSIONS: These findings highlight the potential of urine exosomal mRNAs and lncRNAs profiling in the early diagnosis and provide new insights into the molecular mechanisms involved in BCa.

10.
Front Pharmacol ; 12: 572463, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33828480

RESUMO

Inhibition of activated macrophages is an alternative therapeutic strategy for asthma. We investigated whether a coumarin compound, osthole, isolated from Cnidium monnieri (L.) Cuss, alleviated macrophage activation in vivo and in vitro. Osthole could reduce expression of a marker of activated macrophages, cluster of differentiation (CD)206, in an ovalbumin-challenge model of asthma in mice. Osthole could also inhibit infiltration of inflammatory cells, collagen deposition and production of proinflammatory cytokines [interleukin (IL)-1ß, tumor necrosis factor-ɑ, macrophage migration inhibitory factor (MIF)] in asthmatic mice. In vitro, expression of phosphorylated-IĸBɑ, MIF and M2 cytokines (Ym-1, Fizz-1, arginase-1) in IL-4-induced macrophages decreased upon exposure to the NF-ĸB inhibitor MG-132. In our short hairpin (sh)RNA-MIF-knockdown model, reduced expression of M2 cytokines was detected in the IL-4 + shRNA-MIF group. Osthole could attenuate the proliferation and migration of an IL-4-induced rat alveolar macrophages line (NR8383). Osthole could reduce IL-4-induced translocation of nuclear factor-kappa B (NF-ĸB) in NR8383 cells. Collectively, our results suggest that osthole ameliorates macrophage activation in asthma by suppressing the NF-ĸB/MIF signaling pathway, and might be a potential agent for treating asthma.

11.
Allergy Asthma Immunol Res ; 13(1): 88-105, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33191679

RESUMO

PURPOSE: Recent studies have demonstrated that macrophage migration inhibitory factor (MIF) is of importance in asthmatic inflammation. The role of MIF in modulating airway remodeling has not yet been thoroughly elucidated to date. In the present study, we hypothesized that MIF promoted airway remodeling by intensifying airway smooth muscle cell (ASMC) autophagy and explored the specific mechanisms. METHODS: MIF knockdown in the lung tissues of C57BL/6 mice was conducted by instilling intratracheally adeno-associated virus (AAV) vectors (MIF-mutant AAV9) into mouse lung tissues. Mice genetically deficient in the autophagy marker ATG5 (ATG5+/-) was used to detect the role of autophagy in ovalbumin (OVA)-asthmatic murine models. Moreover, to block the expression of MIF and CD74 in vitro models, inhibitors, antibodies and lentivirus transfection techniques were employed. RESULTS: First, MIF knockdown in the lung tissues of mice showed markedly reduced airway remodeling in OVA murine mice models. Secondly, ASMC autophagy was increased in the OVA-challenged models. Mice genetically deficient in the autophagy marker ATG5 (ATG5+/-) that were primed and challenged with OVA showed lower airway remodeling than genetically wild-type asthmatic mice. Thirdly, MIF can induce ASMC autophagy in vitro. Moreover, the cellular source of MIF which promoted ASMC autophagy was macrophages. Finally, MIF promoted ASMC autophagy in a CD74-dependent manner. CONCLUSIONS: MIF can increase asthmatic airway remodeling by enhancing ASMC autophagy. Macrophage-derived MIF can promote ASMC autophagy by targeting CD74.

12.
Cancer Commun (Lond) ; 41(2): 91-108, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33377623

RESUMO

Bladder cancer (BC) is a heterogeneous disease that characterized by genomic instability and a high mutation rate. Heterogeneity in tumor may partially explain the diversity of responses to targeted therapies and the various clinical outcomes. A combination of cytology and cystoscopy is the standard methodology for BC diagnosis, prognosis, and disease surveillance. However, genomics analyses of single tumor-biopsy specimens may underestimate the mutational burden of heterogeneous tumors. Liquid biopsy, as a promising technology, enables analysis of tumor components in the bodily fluids, such as blood and urine, at multiple time points and provides a minimally invasive approach that can track the evolutionary dynamics and monitor tumor heterogeneity. In this review, we describe the multiple faces of BC heterogeneity at the genomic and transcriptional levels and how they affect clinical care and outcomes. We also summarize the outcomes of liquid biopsy in BC, which plays a potential role in revealing tumor heterogeneity. Finally, we discuss the challenges that must be addressed before liquid biopsy can be widely used in clinical treatment.


Assuntos
Adenocarcinoma , Neoplasias Pancreáticas , Neoplasias da Bexiga Urinária , Biomarcadores Tumorais , Humanos , Biópsia Líquida , Neoplasias Pancreáticas/diagnóstico , Estudos Prospectivos , Neoplasias da Bexiga Urinária/diagnóstico
13.
Protein Sci ; 30(3): 558-570, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33314411

RESUMO

Protein engineering through directed evolution is an effective way to obtain proteins with novel functions with the potential applications as tools for diagnosis or therapeutics. Many natural proteins have undergone directed evolution in vitro in the test tubes in the laboratories worldwide, resulting in the numerous protein variants with novel or enhanced functions. we constructed here an SH2 variant library by randomizing 8 variable residues in its phosphotyrosine (pTyr) binding pocket. Selection of this library by a pTyr peptide led to the identification of SH2 variants with enhanced affinities measured by EC50. Fluorescent polarization was then applied to quantify the binding affinities of the newly identified SH2 variants. As a result, three SH2 variants, named V3, V13 and V24, have comparable binding affinities with the previously identified SH2 triple-mutant superbinder. Biolayer Interferometry assay was employed to disclose the kinetics of the binding of these SH2 superbinders to the phosphotyrosine peptide. The results indicated that all the SH2 superbinders have two-orders increase of the dissociation rate when binding the pTyr peptide while there was no significant change in their associate rates. Intriguingly, though binding the pTyr peptide with comparable affinity with other SH2 superbinders, the V3 does not bind to the sTyr peptide. However, variant V13 and V24 have cross-reactivity with both pTyr and sTyr peptides. The newly identified superbinders could be utilized as tools for the identification of pTyr-containing proteins from tissues under different physiological or pathophysiological conditions and may have the potential in the therapeutics.


Assuntos
Evolução Molecular Direcionada/métodos , Fosfotirosina , Proteínas Proto-Oncogênicas c-fyn , Proteínas Recombinantes , Domínios de Homologia de src/genética , Sítios de Ligação/genética , Técnicas de Visualização da Superfície Celular , Escherichia coli/genética , Humanos , Biblioteca de Peptídeos , Fosfotirosina/química , Fosfotirosina/metabolismo , Ligação Proteica/genética , Engenharia de Proteínas , Proteínas Proto-Oncogênicas c-fyn/química , Proteínas Proto-Oncogênicas c-fyn/genética , Proteínas Proto-Oncogênicas c-fyn/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
14.
Sci Rep ; 10(1): 14892, 2020 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-32913210

RESUMO

The incidence and mortality of primary liver cancer are very high and resection of tumor is the most crucial treatment for it. We aimed to assess the efficacy and safety of combined use of transversus abdominis plane (TAP) block and laryngeal mask airway (LMA) during implementing Enhanced Recovery After Surgery (ERAS) programs for patients with primary liver cancer. This was a prospective, evaluator-blinded, randomized, controlled parallel-arm trial. A total of 96 patients were enrolled (48 in each group). Patients in the control group received general anesthesia with endotracheal intubation, while patients in the TAP + LMA group received general anesthesia with LMA and an ultrasound-guided subcostal TAP block. The primary end-point was postoperative time of readiness for discharge. The secondary end-points were postoperative pain intensity, time to first flatus, quality of recovery (QoR), complications and overall medical cost. Postoperative time of readiness for discharge in the TAP + LMA group [7 (5-11) days] was shorter than that of the control group [8 (5-13) days, P = 0.004]. The postoperative apioid requirement and time to first flatus was lower in the TAP + LMA group [(102.8 ± 12.4) µg, (32.7 ± 5.8) h, respectively] than the control group [(135.7 ± 20.1) µg, P = 0.000; (47.2 ± 7.6) h, P = 0.000; respectively]. The QoR scores were significantly higher in the TAP + LMA group than the control group. The total cost for treatment in the TAP + LMA group [(66,608.4 ± 6,268.4) CNY] was lower than that of the control group [(84,434.0 ± 9,436.2) CNY, P = 0.000]. There was no difference in complications between these two groups. The combined usage of a TAP block and LMA is a simple, safe anesthesia method during implementing ERAS programs for patients with primary liver cancer. It can alleviate surgical stress, accelerate recovery and reduce medical cost.


Assuntos
Músculos Abdominais/inervação , Recuperação Pós-Cirúrgica Melhorada , Máscaras Laríngeas , Neoplasias Hepáticas/cirurgia , Bloqueio Nervoso/métodos , Humanos , Medição da Dor , Dor Pós-Operatória/diagnóstico , Estudos Prospectivos
15.
Exp Cell Res ; 394(1): 112135, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32535035

RESUMO

Podocytes are actin-rich epithelial cells whose effacement and detachment are the main cause of glomerular disease. Crk family proteins: Crk1/2 and CrkL are reported to be important intracellular signaling proteins that are involved in many biological processes. However, the roles of them in maintaining podocyte morphology and function remain poorly understood. In this study, specific knocking down of Crk1/2 and CrkL in podocytes caused abnormal cell morphology, actin cytoskeleton rearrangement and dysfunction in cell adhesion, spreading, migration, and viability. The p130Cas, focal adhesion kinase, phosphatidylinositol 3-kinase/Akt, p38 and JNK signaling pathways involved in these alterations. Furthermore, knocking down CrkL alone conferred a more modest phenotype than did the Crk1/2 knockdown and the double knockdown. Kidney biopsy specimens from patients with focal segmental glomerulosclerosis and minimal change nephropathy showed downregulation of Crk1/2 and CrkL in glomeruli. In zebrafish embryos, Crk1/2 and CrkL knockdown compromised the morphology and caused abnormal glomerular development. Thus, our results suggest that Crk1/2 and CrkL expression are important in podocytes; loss of either will cause podocyte dysfunction, leading to foot process effacement and podocyte detachment.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Podócitos/metabolismo , Podócitos/patologia , Proteínas Proto-Oncogênicas c-crk/metabolismo , Citoesqueleto de Actina/metabolismo , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Glomerulosclerose Segmentar e Focal/genética , Glomerulosclerose Segmentar e Focal/metabolismo , Humanos , Nefropatias/metabolismo , Glomérulos Renais/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo
16.
J Mol Biol ; 432(4): 1169-1182, 2020 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-31954129

RESUMO

The interleukin-18 subfamily belongs to the interleukin-1 family and plays an important role in modulating innate and adaptive immune responses. Dysregulation of IL-18 has been implicated in or correlated with numerous diseases, including inflammatory diseases, autoimmune disorders, and cancer. Thus, blockade of IL-18 signaling may offer therapeutic benefits in many pathological settings. Here, we report the development of synthetic human antibodies that target human IL-18Rß and block IL-18-mediated IFN-γ secretion by inhibiting NF-κB and MAPK dependent pathways. The crystal structure of a potent antagonist antibody in complex with IL-18Rß revealed inhibition through an unexpected allosteric mechanism. Our findings offer a novel means for therapeutic intervention in the IL-18 pathway and may provide a new strategy for targeting cytokine receptors.


Assuntos
Interleucina-18/química , Interleucina-18/metabolismo , Ensaio de Imunoadsorção Enzimática , Células HEK293 , Humanos , Interferon gama/metabolismo , Interleucina-18/imunologia , NF-kappa B/metabolismo , Estrutura Secundária de Proteína , Transdução de Sinais
18.
Mol Cell Proteomics ; 18(2): 372-382, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30482845

RESUMO

Src homology 2 (SH2) domains play an essential role in cellular signal transduction by binding to proteins phosphorylated on Tyr residue. Although Tyr phosphorylation (pY) is a prerequisite for binding for essentially all SH2 domains characterized to date, different SH2 domains prefer specific sequence motifs C-terminal to the pY residue. Because all SH2 domains adopt the same structural fold, it is not well understood how different SH2 domains have acquired the ability to recognize distinct sequence motifs. We have shown previously that the EF and BG loops that connect the secondary structure elements on an SH2 domain dictate its specificity. In this study, we investigated if these surface loops could be engineered to encode diverse specificities. By characterizing a group of SH2 variants selected by different pY peptides from phage-displayed libraries, we show that the EF and BG loops of the Fyn SH2 domain can encode a wide spectrum of specificities, including all three major specificity classes (p + 2, p + 3 and p + 4) of the SH2 domain family. Furthermore, we found that the specificity of a given variant correlates with the sequence feature of the bait peptide used for its isolation, suggesting that an SH2 domain may acquire specificity by co-evolving with its ligand. Intriguingly, we found that the SH2 variants can employ a variety of different mechanisms to confer the same specificity, suggesting the EF and BG loops are highly flexible and adaptable. Our work provides a plausible mechanism for the SH2 domain to acquire the wide spectrum of specificity observed in nature through loop variation with minimal disturbance to the SH2 fold. It is likely that similar mechanisms may have been employed by other modular interaction domains to generate diversity in specificity.


Assuntos
Proteínas Proto-Oncogênicas c-fyn/química , Animais , Cristalografia por Raios X , Variação Genética , Humanos , Ligantes , Modelos Moleculares , Biblioteca de Peptídeos , Estrutura Secundária de Proteína , Proteínas Proto-Oncogênicas c-fyn/genética , Domínios de Homologia de src
19.
J Mol Biol ; 431(2): 336-350, 2019 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-30471255

RESUMO

Hydrophobic cores are often viewed as tightly packed and rigid, but they do show some plasticity and could thus be attractive targets for protein design. Here we explored the role of different functional pressures on the core packing and ligand recognition of the SH3 domain from human Fyn tyrosine kinase. We randomized the hydrophobic core and used phage display to select variants that bound to each of three distinct ligands. The three evolved groups showed remarkable differences in core composition, illustrating the effect of different selective pressures on the core. Changes in the core did not significantly alter protein stability, but were linked closely to changes in binding affinity and specificity. Structural analysis and molecular dynamics simulations revealed the structural basis for altered specificity. The evolved domains had significantly reduced core volumes, which in turn induced increased backbone flexibility. These motions were propagated from the core to the binding surface and induced significant conformational changes. These results show that alternative core packing and consequent allosteric modulation of binding interfaces could be used to engineer proteins with novel functions.


Assuntos
Regulação Alostérica/fisiologia , Ligação Proteica/fisiologia , Proteínas Proto-Oncogênicas c-fyn/metabolismo , Domínios de Homologia de src/fisiologia , Sequência de Aminoácidos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Ligantes , Simulação de Dinâmica Molecular , Conformação Proteica
20.
Structure ; 25(10): 1598-1610.e3, 2017 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-28890361

RESUMO

SH3 domains are protein modules that mediate protein-protein interactions in many eukaryotic signal transduction pathways. The majority of SH3 domains studied thus far act by binding to proline-rich sequences in partner proteins, but a growing number of studies have revealed alternative recognition mechanisms. We have comprehensively surveyed the specificity landscape of human SH3 domains in an unbiased manner using peptide-phage display and deep sequencing. Based on ∼70,000 unique binding peptides, we obtained 154 specificity profiles for 115 SH3 domains, which reveal that roughly half of the SH3 domains exhibit non-canonical specificities and collectively recognize a wide variety of peptide motifs, most of which were previously unknown. Crystal structures of SH3 domains with two distinct non-canonical specificities revealed novel peptide-binding modes through an extended surface outside of the canonical proline-binding site. Our results constitute a significant contribution toward a complete understanding of the mechanisms underlying SH3-mediated cellular responses.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Proteínas/química , Proteínas/metabolismo , Análise de Sequência de Proteína/métodos , Animais , Humanos , Modelos Moleculares , Biblioteca de Peptídeos , Peptídeos/metabolismo , Ligação Proteica , Conformação Proteica , Proteínas/genética , Domínios de Homologia de src
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