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1.
Int J Mol Sci ; 23(8)2022 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-35457148

RESUMO

Exceeded mechanical stress leads to a sublethal injury to anterior cruciate ligament (ACL) fibroblasts, and it will hinder cell mobility and ACL regeneration, and even induce osteoarthritis. The mechano growth factor (MGF) could be responsible for mechanical stress and weakening its negative effects on cell physiological behaviors. In this study, effects of MGF on cell mobility and relevant molecules expression in injured ACL fibroblasts were detected. After an injurious mechanical stretch, the analysis carried out, at 0 and 24 h, respectively, showed that the cell area, roundness, migration, and adhesion of ACL fibroblasts were reduced. MGF (10, 100 ng/mL) treatment could improve cell area, roundness and promote cell migration and adhesion capacity compared with the injured group without MGF. Further study indicated that cell mobility-relevant molecules (PAK1/2, Cdc42, Rac1, RhoA, and ROCK1) expression in ACL fibroblasts was down-regulated at 0 or 24 h after injurious stretch (except Rac1 and RhoA at 0 h). Similarly, MGF improved cell mobility-relevant molecule expression, especially the ROCK1 expression level in ACL fibroblasts at 0 or 24 h after injurious stretch. Protein expression of ROCK1 in injured ACL fibroblasts was also reduced and could be recovered by MGF treatment. In a rabbit partial ACL transection (ACLT) model, ACL exhibited poor regenerative capacity in collagen and extracellular matrix (ECM) synthesis after partial ACLT for 2 or 4 weeks, and MGF remarkably accelerated ACL regeneration and restored its mechanical loading capacity after partial ACLT for four weeks. Our findings suggest that MGF weakens the effects of pathological stress on cell mobility of ACL fibroblasts and accelerates ACL repair, and might be applied as a future treatment approach to ACL rupture in the clinic.


Assuntos
Lesões do Ligamento Cruzado Anterior , Ligamento Cruzado Anterior , Animais , Lesões do Ligamento Cruzado Anterior/metabolismo , Movimento Celular , Colágeno/metabolismo , Fibroblastos/metabolismo , Humanos , Coelhos , Quinases Ativadas por p21/metabolismo , Proteínas rac1 de Ligação ao GTP/metabolismo , Quinases Associadas a rho/metabolismo , Proteína rhoA de Ligação ao GTP/metabolismo
2.
Int J Biochem Cell Biol ; 146: 106207, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35385780

RESUMO

Metastatic Breast Cancer has a poor 25% survival rate and currently there are no clinical therapeutics which target metastasis. 'Migrastatics' are a new drug class which target migration pathway effector proteins in order to inhibit cancer cell invasion and metastasis. The p21-activated kinases (PAKs) are essential drivers of breast cancer cell migration and invasion through their regulation of actin cytoskeletal dynamics. Therefore, the PAKs present as attractive migrastatic candidates. Here we review how PAKs regulate distinct aspects of breast cancer actin dynamics focussing on cytoskeletal reorganisation, cell:matrix adhesion, actomyosin contractility and degradative invasion. Lastly, we discuss the introduction of PAK migrastatics into the well-honed breast cancer clinical pipeline.


Assuntos
Actinas , Neoplasias da Mama , Actinas/metabolismo , Neoplasias da Mama/metabolismo , Citoesqueleto/metabolismo , Feminino , Humanos , Quinases Ativadas por p21/genética , Quinases Ativadas por p21/metabolismo
3.
Int J Mol Sci ; 23(6)2022 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-35328758

RESUMO

The intrinsic inductive properties of atoms or functional groups depend on the chemical properties of either electron-withdrawing groups (EWGs) or electron-donating groups (EDGs). This study aimed to evaluate in silico methods to determine whether changes in chemical properties of the compound by single atomic substitution affect the biological activity of target proteins and whether the results depend on the properties of the functional groups. We found an imidazo[4,5-b]pyridine-based PAK4 inhibitor, compound 1, as an initial hit compound with the well-defined binding mode for PAK4. In this study, we used both experimental and in silico methods to investigate the effect of atomic substitution on biological activity to optimize the initial hit compound. In biological assays, in the case of EWG, as the size of the halogen atom became smaller and the electronegativity increased, the biological activity IC50 value ranged from 5150 nM to inactive; in the case of EDG, biological activity was inactive. Furthermore, we analyzed the interactions of PAK4 with compounds, focusing on the hinge region residues, L398 and E399, and gatekeeper residues, M395 and K350, of the PAK4 protein using molecular docking studies and fragment molecular orbital (FMO) methods to determine the differences between the effect of EWG and EDG on the activity of target proteins. These results of the docking score and binding energy did not explain the differences in biological activity. However, the pair-interaction energy obtained from the results of the FMO method indicated that there was a difference in the interaction energy between the EWG and EDG in the hinge region residues, L398 and E399, as well as in M395 and K350. The two groups with different properties exhibited opposite electrostatic energy and charge transfer energy between L398 and E399. Additionally, we investigated the electron distribution of the parts interacting with the hinge region by visualizing the molecular electrostatic potential (MEP) surface of the compounds. In conclusion, we described the properties of functional groups that affect biological activity using an in silico method, FMO.


Assuntos
Quinases Ativadas por p21 , Simulação de Acoplamento Molecular , Eletricidade Estática , Quinases Ativadas por p21/metabolismo
4.
Mol Cancer ; 21(1): 69, 2022 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-35255921

RESUMO

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is a common invasive malignancy worldwide with poor clinical outcomes. Increasing amount of long non-coding RNAs (lncRNAs) have been reported to be involved in cancer development. However, lncRNAs that are functional in ESCC and the underlying molecular mechanisms remain largely unknown. METHODS: Transcriptomic analysis was performed to identify dysregulated lncRNAs in ESCC tissue samples. The high expression of LINC00680 in ESCC was validated by RT-qPCR, and the oncogenic functions of LINC00680 was investigated by cell proliferation, colony formation, migration and invasion assays in ESCC cells in vitro and xenografts derived from ESCC cells in mice. RNA-seq, competitive endogenous RNA (ceRNA) network analysis, and luciferase reporter assays were carried out to identify LINC00680 target genes and the microRNAs (miRNAs) bound to LINC00680. Antisense oligonucleotides (ASOs) were used for in vivo treatment. RESULTS: Transcriptome profiling revealed that a large number of lncRNAs was dysregulated in ESCC tissues. Notably, LINC00680 was highly expressed, and upregulation of LINC00680 was associated with large tumor size, advanced tumor stage, and poor prognosis. Functionally, knockdown of LINC00680 restrained ESCC cell proliferation, colony formation, migration, and invasion in vitro and inhibited tumor growth in vivo. Mechanistically, LINC00680 was found to act as a ceRNA by sponging miR-423-5p to regulate PAK6 (p21-activated kinase 6) expression in ESCC cells. The cell viability and motility inhibition induced by LINC00680 knockdown was significantly reversed upon PAK6 restoration and miR-423-5p inhibition. Furthermore, ASO targeting LINC00680 substantially suppressed ESCC both in vitro and in vivo. CONCLUSIONS: An oncogenic lncRNA, LINC00680, was identified in ESCC, which functions as a ceRNA by sponging miR-423-5p to promote PAK6 expression and ESCC. LINC00680/miR-423-5p/PAK6 axis may serve as promising diagnostic and prognostic biomarkers and therapeutic targets for ESCC.


Assuntos
Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , MicroRNAs , RNA Longo não Codificante , Quinases Ativadas por p21 , Animais , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Progressão da Doença , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/patologia , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Quinases Ativadas por p21/genética , Quinases Ativadas por p21/metabolismo
5.
Neuroscience ; 490: 155-170, 2022 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-35306145

RESUMO

Intracerebral hemorrhage (ICH) is a hemorrhagic stroke with a high mortality and disability rate. Neurological impairment after ICH is closely associated with neuronal axon damage. Serine/threonine-protein kinase p21 activated kinase 1 (PAK1) participates in cytoskeletal remodeling and regulates the F-actin and G-actin ratio in neuronal axons, but the function of PAK1 after ICH remains unclear. We established an in vivo rat ICH model by autologous whole blood injection into the right basal ganglia and an in vitro neuron oxyhemoglobin intervention. The results showed that the phosphorylated PAK1 level increased while the PAK1 expression level unchanged after ICH, After PAK1 knockdown, PAK1 and phosphorylated PAK1 levels were both reduced. Meanwhile, downstream proteins LIMK1 and cofilin expression levels were unchanged while phosphorylated LIMK1 and phosphorylated cofilin were decreased. F-actin/G-actin ratio decreased after PAK1 knockdown. Moreover, PAK1 knockdown improved short- and long-term neurobehavioral impairments in rats. In vitro, phosphorylated PAK1 expression increased after oxyhemoglobin intervention. After PAK1 knockdown, the axon length of neurons increased while F-actin/G-actin ratio decreased. Spersman correlation analysis showed a negative correlation between phospho-PAK1 fluorescence intensity and neuronal axon length. Knockdown of PAK1 increased the live/dead cell ratio and promoted neurons survival. Our study showed that PAK1 is involved in ICH early secondary brain injury by affecting F-actin/G-actin ratio through the PAK1/LIMK1/cofilin pathway. PAK1 may be an essential target for early secondary brain injury intervention after ICH.


Assuntos
Fatores de Despolimerização de Actina , Lesões Encefálicas , Fatores de Despolimerização de Actina/metabolismo , Actinas/metabolismo , Animais , Axônios/metabolismo , Lesões Encefálicas/metabolismo , Hemorragia Cerebral/metabolismo , Homeostase , Quinases Lim/metabolismo , Oxiemoglobinas/metabolismo , Fosforilação , Ratos , Quinases Ativadas por p21/metabolismo
6.
Front Endocrinol (Lausanne) ; 13: 821849, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35222279

RESUMO

Skeletal muscle accounts for ~80% of insulin-stimulated glucose uptake. The Group I p21-activated kinase 1 (PAK1) is required for the non-canonical insulin-stimulated GLUT4 vesicle translocation in skeletal muscle cells. We found that the abundances of PAK1 protein and its downstream effector in muscle, ARPC1B, are significantly reduced in the skeletal muscle of humans with type 2 diabetes, compared to the non-diabetic controls, making skeletal muscle PAK1 a candidate regulator of glucose homeostasis. Although whole-body PAK1 knockout mice exhibit glucose intolerance and are insulin resistant, the contribution of skeletal muscle PAK1 in particular was unknown. As such, we developed inducible skeletal muscle-specific PAK1 knockout (skmPAK1-iKO) and overexpression (skmPAK1-iOE) mouse models to evaluate the role of PAK1 in skeletal muscle insulin sensitivity and glucose homeostasis. Using intraperitoneal glucose tolerance and insulin tolerance testing, we found that skeletal muscle PAK1 is required for maintaining whole body glucose homeostasis. Moreover, PAK1 enrichment in GLUT4-myc-L6 myoblasts preserves normal insulin-stimulated GLUT4 translocation under insulin resistance conditions. Unexpectedly, skmPAK1-iKO also showed aberrant plasma insulin levels following a glucose challenge. By applying conditioned media from PAK1-enriched myotubes or myoblasts to ß-cells in culture, we established that a muscle-derived circulating factor(s) could enhance ß-cell function. Taken together, these data suggest that PAK1 levels in the skeletal muscle can regulate not only skeletal muscle insulin sensitivity, but can also engage in tissue crosstalk with pancreatic ß-cells, unveiling a new molecular mechanism by which PAK1 regulates whole-body glucose homeostasis.


Assuntos
Diabetes Mellitus Tipo 2 , Quinases Ativadas por p21 , Animais , Diabetes Mellitus Tipo 2/metabolismo , Glucose/metabolismo , Homeostase , Camundongos , Músculo Esquelético/metabolismo , Transdução de Sinais , Quinases Ativadas por p21/genética , Quinases Ativadas por p21/metabolismo
7.
Microbiol Spectr ; 10(1): e0226521, 2022 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-35138149

RESUMO

Avian hepatitis E virus (HEV) causes liver diseases and multiple extrahepatic disorders in chickens. However, the mechanisms involved in avian HEV entry remain elusive. Herein, we identified the RAS-related protein 1b (Rap1b) as a potential HEV-ORF2 protein interacting candidate. Experimental infection of chickens and cells with an avian HEV isolate from China (CaHEV) led to upregulated expression and activation of Rap1b both in vivo and in vitro. By using CaHEV capsid as mimic of virion to treat cell in vitro, it appears that the interaction between the viral capsid and Rap1b promoted cell membrane recruitment of the downstream effector Rap1-interacting molecule (RIAM). In turn, RIAM further enhanced Talin-1 membrane recruitment and retention, which led to the activation of integrin α5/ß1, as well as integrin-associated membrane protein kinases, including focal adhesion kinase (FAK). Meanwhile, FAK activation triggered activation of downstream signaling molecules, such as Ras-related C3 botulinum toxin substrate 1 RAC1 cell division cycle 42 (CDC42), p21-activated kinase 1 (PAK1), and LIM domain kinase 1 (LIMK1). Finally, F-actin rearrangement induced by Cofilin led to the formation of lamellipodia, filopodia, and stress fibers, contributes to plasma membrane remodeling, and might enhance CaHEV virion internalization. In conclusion, our data suggested that Rap1b activation was triggered during CaHEV infection and appeared to require interaction between CaHEV-ORF2 and Rap1b, thereby further inducing membrane recruitment of Talin-1. Membrane-bound Talin-1 then activates key Integrin-FAK-Cofilin cascades involved in modulation of actin kinetics, and finally leads to F-actin rearrangement and membrane remodeling to potentially facilitate internalization of CaHEV virions into permissive cells. IMPORTANCE Rap1b is a multifunctional protein that is responsible for cell adhesion, growth, and differentiation. The inactive form of Rap1b is phosphorylated and distributed in the cytoplasm, while active Rap1b is prenylated and loaded with GTP to the cell membrane. In this study, the activation of Rap1b was induced during the early stage of avian HEV infection under the regulation of PKA and SmgGDS. Continuously activated Rap1b recruited its effector RIAM to the membrane, thereby inducing the membrane recruitment of Talin-1 that led to the activation of membrane α5/ß1 integrins. The triggering of the signaling pathway-associated Integrin α5/ß1-FAK-CDC42&RAC1-PAK1-LIMK1-Cofilin culminated in F-actin polymerization and membrane remodeling that might promote avian HEV virion internalization. These findings suggested a novel mechanism that is potentially utilized by avian HEV to invade susceptible cells.


Assuntos
Citoesqueleto/metabolismo , Hepatite Viral Animal/metabolismo , Hepevirus/patogenicidade , Doenças das Aves Domésticas/metabolismo , Proteínas Virais/metabolismo , Internalização do Vírus , Proteínas rap de Ligação ao GTP/metabolismo , Actinas/genética , Actinas/metabolismo , Animais , Galinhas , Citoesqueleto/genética , Citoesqueleto/virologia , Hepatite Viral Animal/genética , Hepatite Viral Animal/virologia , Hepevirus/genética , Interações Hospedeiro-Patógeno , Doenças das Aves Domésticas/genética , Doenças das Aves Domésticas/virologia , Ligação Proteica , Proteínas Virais/genética , Proteína cdc42 de Ligação ao GTP/genética , Proteína cdc42 de Ligação ao GTP/metabolismo , Quinases Ativadas por p21/genética , Quinases Ativadas por p21/metabolismo , Proteínas rap de Ligação ao GTP/genética
8.
J Alzheimers Dis ; 86(3): 1255-1273, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35180113

RESUMO

BACKGROUND: Several recent findings have revealed that targeting of cell cycle reentry and (or) progression may provide an opportunity for the therapeutic intervention of Alzheimer's disease (AD). FOXG1 has been shown to play important roles in pattern formation, cell proliferation, and cell specification. Thus far, the roles of FoxG1 and its involvement in AD are largely unknown. OBJECTIVE: Our study aimed to explore the intervention effect of FOXG1 on AD pathology and its potential mechanism with a particular focus on cell cycle regulation. METHODS: We investigated the association of Foxg1 gene variants with AD-like behavioral deficits, p21 expression, neuronal apoptosis, and amyloid-ß (Aß) aggregate formation; we further determined whether targeting FOXG1-regulated cell cycle has therapeutic potential in AD. RESULTS: Paralleling AD-like behavioral abnormalities, neuronal apoptosis, and Aß deposits, a significant reduction in the expression of FOXG1 was observed in APP/PS1 mice at 6 months of age. Using the APP/PS1;Foxg1fl/fl-CreAAV mouse line, we found that FOXG1 potentially antagonized cell cycle reentry by negatively regulating the levels of p21-activated kinase (PAK3). By reducing p21cip1-mediated arrest at the G2 stage and regulating cyclin A1- and cyclin B-dependent progression patterns of the cell cycle, FOXG1 blocked neuronal apoptosis and Aß deposition. CONCLUSION: These results indicate that FOXG1 contributes to the regulation of the neuronal cell cycle, thereby affecting brain abnormalities in AD. An elevation of the FOXG1 level, either pharmacologically or through other means, could present a therapeutic strategy for AD.


Assuntos
Doença de Alzheimer , Fatores de Transcrição Forkhead , Proteínas do Tecido Nervoso , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Doença de Alzheimer/terapia , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Ciclo Celular , Modelos Animais de Doenças , Fatores de Transcrição Forkhead/metabolismo , Humanos , Camundongos , Camundongos Transgênicos , Proteínas do Tecido Nervoso/metabolismo , Presenilina-1/metabolismo , Quinases Ativadas por p21/metabolismo
9.
Mol Cancer Res ; 20(5): 699-711, 2022 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-35082167

RESUMO

Because loss of the NF2 tumor suppressor gene results in p21-activated kinase (Pak) activation, PAK inhibitors hold promise for the treatment of NF2-deficient tumors. To test this possibility, we asked if loss of Pak2, a highly expressed group I PAK member, affects the development of malignant mesothelioma in Nf2;Cdkn2a-deficient (NC) mice and the growth properties of NC mesothelioma cells in culture. In vivo, deletion of Pak2 resulted in a markedly decreased incidence and delayed onset of both pleural and peritoneal malignant mesotheliomas in NC mice. In vitro, Pak2 deletion decreased malignant mesothelioma cell viability, migration, clonogenicity, and spheroid formation. RNA-sequencing analysis demonstrated downregulated expression of Hedgehog and Wnt pathway genes in NC;Pak2-/- mesothelioma cells versus NC;Pak2+/+ mesothelioma cells. Targeting of the Hedgehog signaling component Gli1 or its target gene Myc inhibited cell viability and spheroid formation in NC;P+/+ mesothelioma cells. Kinome profiling uncovered kinase changes indicative of EMT in NC;Pak2-/- mesothelioma cells, suggesting that Pak2-deficient malignant mesotheliomas can adapt by reprogramming their kinome in the absence of Pak activity. The identification of such compensatory pathways offers opportunities for rational combination therapies to circumvent resistance to anti-PAK drugs. IMPLICATIONS: We provide evidence supporting a role for PAK inhibitors in treating NF2-deficient tumors. NF2-deficient tumors lacking Pak2 eventually adapt by kinome reprogramming, presenting opportunities for combination therapies to bypass anti-PAK drug resistance.


Assuntos
Mesotelioma Maligno , Mesotelioma , Animais , Proteínas Hedgehog/genética , Humanos , Mesotelioma/tratamento farmacológico , Mesotelioma/genética , Camundongos , Via de Sinalização Wnt , Quinases Ativadas por p21/genética , Quinases Ativadas por p21/metabolismo
10.
Brain Res ; 1778: 147781, 2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35016853

RESUMO

Leucine-rich repeat kinase 2 (LRRK2) has taken center stage in Parkinson's disease (PD) research as mutations cause familial PD and more common variants increase lifetime risk for disease. One unique feature in LRRK2 is the coexistence of GTPase/Roc (Ras of complex) and kinase catalytic functions, bridged by a COR (C-terminal Of Roc) platform for dimerization. Multiple PD mutations are located within the Roc/GTPase domain and concomitantly lead to defective GTPase activity and augmented kinase activity in cells, supporting a crosstalk between GTPase and kinase domains. In addition, biochemical and structural data highlight the importance of Roc as a molecular switch modulating LRRK2 monomer-to-dimer equilibrium and building the interface for interaction with binding partners. Here we review the effects of PD Roc mutations on LRRK2 function and discuss the importance of Roc as a hub for multiple molecular interactions relevant for the regulation of cytoskeletal dynamics and intracellular trafficking pathways. Among the well-characterized Roc interactors, we focused on the cytoskeletal-related kinase p21-activated kinase 6 (PAK6). We report the affinity between LRRK2-Roc and PAK6 measured by microscale thermophoresis (MST). We further show that PAK6 can modulate LRRK2-mediated phosphorylation of RAB substrates in the presence of LRRK2 wild-type (WT) or the PD G2019S kinase mutant but not when the PD Roc mutation R1441G is expressed. These findings support a mechanism whereby mutations in Roc might affect LRRK2 activity through impaired protein-protein interaction in the cell.


Assuntos
Proteínas 14-3-3/metabolismo , GTP Fosfo-Hidrolases/metabolismo , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/metabolismo , Doença de Parkinson/metabolismo , Domínios e Motivos de Interação entre Proteínas , Quinases Ativadas por p21/metabolismo , Humanos , Fosforilação
11.
Protein Cell ; 13(1): 6-25, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-33306168

RESUMO

The serine/threonine p21-activated kinases (PAKs), as main effectors of the Rho GTPases Cdc42 and Rac, represent a group of important molecular switches linking the complex cytoskeletal networks to broad neural activity. PAKs show wide expression in the brain, but they differ in specific cell types, brain regions, and developmental stages. PAKs play an essential and differential role in controlling neural cytoskeletal remodeling and are related to the development and fate of neurons as well as the structural and functional plasticity of dendritic spines. PAK-mediated actin signaling and interacting functional networks represent a common pathway frequently affected in multiple neurodevelopmental and neurodegenerative disorders. Considering specific small-molecule agonists and inhibitors for PAKs have been developed in cancer treatment, comprehensive knowledge about the role of PAKs in neural cytoskeletal remodeling will promote our understanding of the complex mechanisms underlying neurological diseases, which may also represent potential therapeutic targets of these diseases.


Assuntos
Citoesqueleto/enzimologia , Doenças do Sistema Nervoso/enzimologia , Neurônios/enzimologia , Transdução de Sinais , Quinases Ativadas por p21/metabolismo , Animais , Citoesqueleto/genética , Humanos , Doenças do Sistema Nervoso/genética , Quinases Ativadas por p21/genética
12.
J Cell Biochem ; 123(2): 375-389, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34750857

RESUMO

P21-activated kinases (PAKs) regulate processes associated with cytoskeletal rearrangements, such as cell division, adhesion, and migration. The possible regulatory role of PAKs in cell metabolism has not been well explored, but increasing evidence suggests that a cell metabolic phenotype is related to cell interactions with the microenvironment. We analyzed the impact of PAK inhibition by small molecule inhibitors, small interfering RNA, or gene knockout on the rates of mitochondrial respiration and aerobic glycolysis. Pharmacological inhibition of PAK group I by IPA-3 induced a strong decrease in metabolic rates in human adherent cancer cell lines, leukemia/lymphoma cell lines, and primary leukemia cells. The immediate effect of FRAX597, which inhibits PAK kinase activity, was moderate, indicating that PAK nonkinase functions are essential for cell metabolism. Selective downregulation or deletion of PAK2 was associated with a shift toward oxidative phosphorylation. In contrast, PAK1 knockout resulted in increased glycolysis. However, the overall metabolic capacity was not substantially reduced by PAK1 or PAK2 deletion, possibly due to partial redundancy in PAK1/PAK2 regulatory roles or to activation of other compensatory mechanisms.


Assuntos
Mitocôndrias/enzimologia , Proteínas de Neoplasias/metabolismo , Neoplasias/enzimologia , Microambiente Tumoral , Quinases Ativadas por p21/metabolismo , Células HEK293 , Células HeLa , Humanos , Mitocôndrias/genética , Proteínas de Neoplasias/genética , Neoplasias/genética , Quinases Ativadas por p21/genética
13.
Biol Rev Camb Philos Soc ; 97(2): 615-639, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34811887

RESUMO

p21-activated kinases (PAKs) are a family of cell division control protein 42/ras-related C3 botulinum toxin substrate 1 (Cdc42/Rac1)-activated serine/threonine kinases. Group I PAKs (PAK1-3) have distinct activation mechanisms from group II PAKs (PAK4-6) and are the focus of this review. In transformed cancer cells, PAKs regulate a variety of cellular processes and molecular pathways which are also important for myelin formation and repair in the central nervous system (CNS). De novo mutations in group I PAKs are frequently seen in children with neurodevelopmental defects and white matter anomalies. Group I PAKs regulate virtually every aspect of neuronal development and function. Yet their functions in CNS myelination and remyelination remain incompletely defined. Herein, we highlight the current understanding of PAKs in regulating cellular and molecular pathways and discuss the status of PAK-regulated pathways in oligodendrocyte development. We point out outstanding questions and future directions in the research field of group I PAKs and oligodendrocyte development.


Assuntos
Bainha de Mielina , Quinases Ativadas por p21 , Sistema Nervoso Central , Bainha de Mielina/metabolismo , Quinases Ativadas por p21/genética , Quinases Ativadas por p21/metabolismo
14.
Cell Death Differ ; 29(4): 818-831, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34799729

RESUMO

Cholangiocarcinoma (CCA), consisting of three subtypes-intrahepatic (iCCA), perihilar (pCCA), and distal (dCCA), is a highly aggressive cancer arising from the bile duct and has an extremely poor prognosis. Pemigatinib is the only FDA-approved targeted drug for CCA, and the CCA treatment options are substantially insufficient considering its poor prognosis and increasing morbidity. Here, we performed next-generation sequencing (NGS) of 15 pCCAs and 16 dCCAs and detected the expression of SMAD4, a frequently mutated gene, in 261 CCAs. By univariate and multivariate analyses, we identified Smad4 as a favorable prognostic biomarker in iCCA and pCCA. With in vitro and in vivo experiments, we demonstrated that Smad4 suppressed CCA proliferation, migration and invasion by inhibiting ß-catenin-S675 phosphorylation and intranuclear translocation. We applied LC-MS/MS and multiple biochemical techniques and identified PP1A as the phosphatase in Smad4-mediated dephosphorylation of PAK1-T423, which is responsible for ß-catenin-S675 phosphorylation. Moreover, we demonstrated that MYO18A is the PP1-interacting protein of PP1A for substrate recognition in CCA. MYO18A interacts with PP1A via its RVFFR motif and interacts with Smad4 via CC domain. Patients with coexpression of MYO18A and Smad4 have a more favorable prognosis than other patients. Smad4 enhances Pemigatinib efficiency, and Smad4 knockdown results in Pemigatinib resistance. In conclusion, coexpression of Smad4 and MYO18A is a favorable prognostic indicator for iCCA and pCCA. The Smad4-MYO18A-PP1A complex dephosphorylates PAK1-T423 and thus inhibits ß-catenin-S675 phosphorylation and its intranuclear localization. Smad4 suppresses CCA proliferation, migration, invasion, and sensitivity to Pemigatinib by governing the phosphorylation and intracellular localization of ß-catenin.


Assuntos
Neoplasias dos Ductos Biliares , Colangiocarcinoma , Neoplasias dos Ductos Biliares/tratamento farmacológico , Neoplasias dos Ductos Biliares/genética , Ductos Biliares Intra-Hepáticos/metabolismo , Ductos Biliares Intra-Hepáticos/patologia , Colangiocarcinoma/tratamento farmacológico , Colangiocarcinoma/genética , Cromatografia Líquida , Humanos , Morfolinas , Miosinas/metabolismo , Fosforilação , Pirimidinas , Pirróis , Proteína Smad4/metabolismo , Espectrometria de Massas em Tandem , beta Catenina/metabolismo , Quinases Ativadas por p21/genética , Quinases Ativadas por p21/metabolismo
15.
Toxicol Lett ; 355: 160-169, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34843874

RESUMO

Two new psychoactive substances (NPSs) classified as phenethylamines, namely 2-((2-(4-Iodo-2,5-dimethoxyphenyl)ethylamino)methyl)phenol (25I-NBOH) and 2-(((2-(4-chloro-2,5-dimethoxyphenyl)ethyl)amino)methyl)phenol (25C-NBOH), are being abused by people seeking recreational hallucinogens. These NPSs may cause serious health problems as their adverse effects are not known in most cases. Therefore, in the present study, we evaluated the cardiotoxicity of 25I-NBOH and 25C-NBOH using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, rat electrocardiography (ECG), Langendorff test, and human ether-a-go-go-related gene (hERG) assay. Furthermore, we analyzed the expression levels of p21 CDC42/RAC1-activated kinase 1 (PAK1), which is known to play various roles in the cardiovascular system. In the MTT assay, treatment with 25I-NBOH or 25C-NBOH dramatically decreased viability of H9c2 cardiomyocytes. Meanwhile, these two compounds significantly increased QT intervals and RR intervals in the rat ECG measurement. 25I-NBOH down-regulated the PAK1 protein expression in rat primary cardiomyocytes as well as H9c2 cells. However, 25C-NBOH had no effect on the PAK1 expression in H9c2 cells. In an in-depth study, 25I-NBOH inhibited potassium channels in the hERG assay, but in ex vivo test, the substance did not affect the left ventricular developed pressure (LVDP) and heart rate of the isolated rat hearts. Taken together, these results suggest that both 25I-NBOH and 25C-NBOH may have adverse cardiovascular effect. Further investigation would be needed to determine which factors mainly influence the relationship between PAK1 expression and cardiotoxicity.


Assuntos
Cardiopatias/induzido quimicamente , Miócitos Cardíacos/efeitos dos fármacos , Psicotrópicos/toxicidade , Compostos de Amônio Quaternário/toxicidade , Animais , Células CHO , Linhagem Celular , Cricetulus , Redução da Medicação , Canal de Potássio ERG1/genética , Canal de Potássio ERG1/metabolismo , Eletrocardiografia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Estrutura Molecular , Compostos de Amônio Quaternário/administração & dosagem , Ratos , Ratos Sprague-Dawley , Quinases Ativadas por p21/genética , Quinases Ativadas por p21/metabolismo
16.
Mol Biol Cell ; 33(1): ar9, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34788129

RESUMO

The ability of cells to sense chemical gradients is essential during development, morphogenesis, and immune responses. Although much is known about chemoattraction, chemorepulsion remains poorly understood. Proliferating Dictyostelium cells secrete a chemorepellent protein called AprA. AprA prevents pseudopod formation at the region of the cell closest to the source of AprA, causing the random movement of cells to be biased away from the AprA. Activation of Ras proteins in a localized sector of a cell cortex helps to induce pseudopod formation, and Ras proteins are needed for AprA chemorepulsion. Here we show that AprA locally inhibits Ras cortical activation through the G protein-coupled receptor GrlH, the G protein subunits Gß and Gα8, Ras protein RasG, protein kinase B, the p21-activated kinase PakD, and the extracellular signal-regulated kinase Erk1. Diffusion calculations and experiments indicate that in a colony of cells, high extracellular concentrations of AprA in the center can globally inhibit Ras activation, while a gradient of AprA that naturally forms at the edge of the colony allows cells to activate Ras at sectors of the cell other than the sector of the cell closest to the center of the colony, effectively inducing both repulsion from the colony and cell differentiation. Together, these results suggest that a pathway that inhibits local Ras activation can mediate chemorepulsion.


Assuntos
Inibição de Migração Celular/fisiologia , Dictyostelium/efeitos dos fármacos , Dictyostelium/metabolismo , Inibição de Migração Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Quimiotaxia/efeitos dos fármacos , Quimiotaxia/fisiologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Proteínas de Protozoários/metabolismo , Pseudópodes/efeitos dos fármacos , Pseudópodes/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais/efeitos dos fármacos , Quinases Ativadas por p21/metabolismo , Proteínas ras/metabolismo
17.
Cell Death Differ ; 29(1): 14-27, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34262144

RESUMO

Colorectal cancer (CRC) is the third most diagnosed cancer and the second leading cause of cancer-related deaths. However, there are few effective therapeutic targets for CRC patients. Here, we found that CDK15 was highly expressed in human CRC and negatively correlated with patient prognosis and overall survival in tissue microarray. Knockdown of CDK15 suppressed cell proliferation and anchorage-independent growth of CRC cells and inhibited tumor growth in cell line-derived xenograft (CDX) model. Importantly, knockout of CDK15 in mice retarded AOM/DSS-induced tumorigenesis and CDK15 silencing by lentivirus significantly suppressed tumor progression in patient-derived xenograft (PDX) model. Mechanistically, CDK15 could bind PAK4 and phosphorylate PAK4 at S291 site. Phosphorylation of PAK4 at the S291 residue promoted cell proliferation and anchorage-independent growth through ß-catenin/c-Myc, MEK/ERK signaling pathway in CRC. Moreover, inhibition of PAK4 reversed the tumorigenic function of CDK15 in CRC cells and pharmacological targeting PAK4 suppressed tumor growth in PDX models. Thus, our data reveal the pivotal role of CDK15 in CRC progression and demonstrate CDK15 promotes CRC tumorigenesis by phosphorylating PAK4. Hence, the CDK15-PAK4 axis may serve as a novel therapeutic target for CRC.


Assuntos
Neoplasias Colorretais , Quinases Ciclina-Dependentes/metabolismo , beta Catenina , Animais , Neoplasias Colorretais/metabolismo , Humanos , Sistema de Sinalização das MAP Quinases , Camundongos , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Transdução de Sinais , beta Catenina/metabolismo , Quinases Ativadas por p21/genética , Quinases Ativadas por p21/metabolismo
18.
Br J Cancer ; 126(7): 1037-1046, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34912075

RESUMO

BACKGROUND: Due to the high recurrence and low 5-year survival rates of esophageal squamous cell carcinoma (ESCC) after treatment, the discovery of novel drugs for recurrence chemoprevention is of particular importance. METHODS: We screened the FDA-approved drug library and found that Nuplazid, an atypical antipsychotic that acts as an effective 5-HT 2 A receptor inverse agonist, could potentially exert anticancer effects in vitro and in vivo on ESCC. RESULTS: Pull-down results indicated that Nuplazid binds with p21-activated kinase 4 (PAK4), and a kinase assay showed that Nuplazid strongly suppressed PAK4 kinase activity. Moreover, Nuplazid exhibited inhibitory effects on ESCC in vivo. CONCLUSIONS: Our findings indicate that Nuplazid can suppress ESCC progression through targeting PAK4.


Assuntos
Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Linhagem Celular Tumoral , Proliferação de Células , Neoplasias Esofágicas/metabolismo , Carcinoma de Células Escamosas do Esôfago/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Piperidinas , Ureia/análogos & derivados , Quinases Ativadas por p21/metabolismo
19.
Reprod Biol Endocrinol ; 19(1): 181, 2021 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-34879863

RESUMO

BACKGROUND: The quality of the early embryo is vital to embryonic development and implantation. As a highly conserved serine/threonine kinase, p21-activated kinase 2 (Pak2) participates in diverse biologic processes, especially in cytoskeleton remodeling and cell apoptosis. In mice, Pak2 knock out and endothelial depletion of Pak2 showed embryonic lethality. However, the role of Pak2 in preimplantation embryos remains unelucidated. METHODS: In the present work, Pak2 was reduced using a specific small interfering RNA in early mouse embryos, validating the unique roles of Pak2 in spindle assembly and DNA repair during mice early embryonic development. We also employed immunoblotting, immunostaining, in vitro fertilization (IVF) and image quantification analyses to test the Pak2 knockdown on the embryonic development progression, spindle assembly, chromosome alignment, oxidative stress, DNA lesions and blastocyst cell apoptosis. Areas in chromatin with γH2AX were detected by immunofluorescence microscopy and serve as a biomarker of DNA damages. RESULTS: We found that Pak2 knockdown significantly reduced blastocyst formation of early embryos. In addition, Pak2 reduction led to dramatically increased abnormal spindle assembly and chromosomal aberrations in the embryos. We noted the overproduction of reactive oxygen species (ROS) with Pak2 knockdown in embryos. In response to DNA double strand breaks (DSBs), the histone protein H2AX is specifically phosphorylated at serine139 to generate γH2AX, which is used to quantitative DSBs. In this research, Pak2 knockdown also resulted in the accumulation of phosphorylated γH2AX, indicative of increased embryonic DNA damage. Commensurate with this, a significantly augmented rate of blastocyst cell apoptosis was detected in Pak2-KD embryos compared to their controls. CONCLUSIONS: Collectively, our data suggest that Pak2 may serve as an important regulator of spindle assembly and DNA repair, and thus participate in the development of early mouse embryos.


Assuntos
Quebras de DNA de Cadeia Dupla , Desenvolvimento Embrionário/genética , Estresse Oxidativo/genética , Quinases Ativadas por p21/genética , Animais , Apoptose/genética , Feminino , Técnicas de Silenciamento de Genes , Camundongos , Gravidez , RNA Interferente Pequeno , Espécies Reativas de Oxigênio/metabolismo , Quinases Ativadas por p21/metabolismo
20.
Int J Mol Sci ; 22(23)2021 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-34884932

RESUMO

Acetyl-CoA carboxylase (ACC) is the first enzyme regulating de novo lipid synthesis via the carboxylation of acetyl-CoA into malonyl-CoA. The inhibition of its activity decreases lipogenesis and, in parallel, increases the acetyl-CoA content, which serves as a substrate for protein acetylation. Several findings support a role for acetylation signaling in coordinating signaling systems that drive platelet cytoskeletal changes and aggregation. Therefore, we investigated the impact of ACC inhibition on tubulin acetylation and platelet functions. Human platelets were incubated 2 h with CP640.186, a pharmacological ACC inhibitor, prior to thrombin stimulation. We have herein demonstrated that CP640.186 treatment does not affect overall platelet lipid content, yet it is associated with increased tubulin acetylation levels, both at the basal state and after thrombin stimulation. This resulted in impaired platelet aggregation. Similar results were obtained using human platelets that were pretreated with tubacin, an inhibitor of tubulin deacetylase HDAC6. In addition, both ACC and HDAC6 inhibitions block key platelet cytoskeleton signaling events, including Rac1 GTPase activation and the phosphorylation of its downstream effector, p21-activated kinase 2 (PAK2). However, neither CP640.186 nor tubacin affects thrombin-induced actin cytoskeleton remodeling, while ACC inhibition results in decreased thrombin-induced reactive oxygen species (ROS) production and extracellular signal-regulated kinase (ERK) phosphorylation. We conclude that when using washed human platelets, ACC inhibition limits tubulin deacetylation upon thrombin stimulation, which in turn impairs platelet aggregation. The mechanism involves a downregulation of the Rac1/PAK2 pathway, being independent of actin cytoskeleton.


Assuntos
Acetil-CoA Carboxilase/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Trombina/farmacologia , Tubulina (Proteína)/metabolismo , Acetil-CoA Carboxilase/metabolismo , Acetilação , Citoesqueleto de Actina/metabolismo , Plaquetas/efeitos dos fármacos , Plaquetas/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Microtúbulos/efeitos dos fármacos , Microtúbulos/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Fosforilação/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Trombina/metabolismo , Quinases Ativadas por p21/metabolismo , Proteínas rac1 de Ligação ao GTP/metabolismo
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