RESUMO
Classical swine fever (CSF), caused by classical swine fever virus (CSFV), is an important and highly infectious pig disease worldwide. Kinesin-1, a molecular motor responsible for transporting cargo along the microtubule, has been demonstrated to be involved in the infections of diverse viruses. However, the role of kinesin-1 in the CSFV life cycle remains unknown. Here, we first found that Kif5B played a positive role in CSFV entry by knockdown or overexpression of Kif5B. Subsequently, we showed that Kif5B was associated with the endosomal and lysosomal trafficking of CSFV in the early stage of CSFV infection, which was reflected by the colocalization of Kif5B and Rab7, Rab11, or Lamp1. Interestingly, trichostatin A (TSA) treatment promoted CSFV proliferation, suggesting that microtubule acetylation facilitated CSFV endocytosis. The results of chemical inhibitors and RNA interference showed that Rac1 and Cdc42 induced microtubule acetylation after CSFV infection. Furthermore, confocal microscopy revealed that cooperation between Kif5B and dynein help CSFV particles move in both directions along microtubules. Collectively, our study shed light on the role of kinesin motor Kif5B in CSFV endocytic trafficking, indicating the dynein/kinesin-mediated bidirectional CSFV movement. The elucidation of this study provides the foundation for developing CSFV antiviral drugs. IMPORTANCE The minus end-directed cytoplasmic dynein and the plus end-directed kinesin-1 are the molecular motors that transport cargo on microtubules in intracellular trafficking, which plays a notable role in the life cycles of diverse viruses. Our previous studies have reported that the CSFV entry host cell is dependent on the microtubule-based motor dynein. However, little is known about the involvement of kinesin-1 in CSFV infection. Here, we revealed the critical role of kinesin-1 that regulated the viral endocytosis along acetylated microtubules induced by Cdc42 and Rac1 after CSFV entry. Mechanistically, once CSFV transported by dynein met an obstacle, it recruited kinesin-1 to move in reverse to the anchor position. This study extends the theoretical basis of intracellular transport of CSFV and provides a potential target for the control and treatment of CSFV infection.
Assuntos
Vírus da Febre Suína Clássica , Peste Suína Clássica , Cinesinas , Animais , Vírus da Febre Suína Clássica/fisiologia , Dineínas/metabolismo , Endocitose , Cinesinas/genética , Cinesinas/metabolismo , Microtúbulos/metabolismo , Microtúbulos/virologia , Suínos , Internalização do Vírus , Replicação Viral/efeitos dos fármacos , Inibidores da Síntese de Proteínas/farmacologia , Transporte ProteicoRESUMO
ALK-positive histiocytosis is a rare histiocytic disease characterized by ALK positivity. It was first described in 2008 as a systemic disease in infants. The disease often shows positivity for CD68 and CD163 on immunohistochemistry, and genomic analysis frequently reveals KIF5B::ALK fusions. ALK-positive histiocytosis typically follows an indolent course and has a promising prognosis, with conventional treatments usually being effective. Here, we report a rare case of ALK-positive histiocytosis with exclusive involvement of the central nervous system in a 33-year-old Asian adult woman. Although cranial MRI suggested a meningioma, immunohistochemical workup showed that the ALK-positive tumor cells expressed macrophage/histiocyte markers such as CD163 and CD68. Additionally, second-generation sequencing revealed a KIF5B::ALK fusion. Our case highlights the importance of the differential diagnosis in adult central nervous system tumors, emphasizing the combination of morphology, immunophenotype, and molecular approach with ALK status evaluation to confirm a diagnosis of ALK-positive histiocytosis. This case also expands the clinicopathologic spectrum of ALK-positive histiocytosis.
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BACKGROUND: RET fusions are rare oncogenic drivers in non-small cell lung cancer (NSCLC). While activating RET rearrangements are found in NSCLC patients harboring epidermal growth factor receptor (EGFR) genetic alterations at resistance to EGFR inhibitors, the extent to which co-occurring genomic alterations exist and how they might affect prognosis or therapy response is poorly understood. METHODS: Targeted next-generation sequencing (NGS) was used to assess 380 baseline patients with primary RET fusions and 71 EGFR-mutated NSCLC patients who acquired RET fusions after developing resistance to EGFR-tyrosine kinase inhibitors (EGFR-TKIs). RESULTS: Primary RET fusions were more likely associated with females and younger age, with KIF5B being the predominant fusion partner. In baseline patients, both SMAD4 (5.3% vs. 0.0%, P = 0.044) and MYC copy-number gain variants (6.9% vs. 0.0%, P = 0.009) were more frequently co-mutated with KIF5B-RET than CCDC6-RET. By contrast, CDKN2A (11.3% vs. 2.4%, P = 0.003) mutations were significantly enriched in CCDC6-RET-rearranged baseline patients. A significant increase in the proportion of CCDC6-RET was observed in acquired RET-rearranged patients (47.3% vs. 22.5%, P < 0.001). The median progression-free survival (PFS) of patients harboring RB1 and TP53 double-mutations (5.5 vs. 10.0 months, P = 0.020) or ERBB2 amplification (5.6 vs. 10.0 months, P = 0.041) was significantly shorter than the wild-type counterparts. Moreover, we identified that RET fusions were more likely associated with acquired resistance (AR) to third-generation EGFR-TKIs than previous generations of EGFR-TKIs. CONCLUSIONS: In conclusion, we depicted the mutational profiles of NSCLC patients who harbor RET fusions at baseline or after resistance to EGFR-TKIs. Furthermore, our results suggest that RET fusions mediate secondary resistance to third-generation EGFR-TKIs and might be associated with poor prognosis in patients with NSCLC.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Proteínas Proto-Oncogênicas c-ret/genética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Receptores ErbB/genética , Receptores ErbB/metabolismo , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Mutação , Oncogenes , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas c-ret/metabolismoRESUMO
Kyphomelic dysplasia is a heterogeneous group of skeletal dysplasias characterized by severe bowing of the limbs associated with other variable findings, such as narrow thorax and abnormal facies. We searched for the genetic etiology of this disorder. Four individuals diagnosed with kyphomelic dysplasia were enrolled. We performed whole-exome sequencing and evaluated the pathogenicity of the identified variants. All individuals had de novo heterozygous variants in KIF5B encoding kinesin-1 heavy chain: two with c.272A>G:p.(Lys91Arg), one with c.584C>A:p.(Thr195Lys), and the other with c.701G>T:p.(Gly234Val). All variants involved conserved amino acids in or close to the ATPase activity-related motifs in the catalytic motor domain of the KIF5B protein. All individuals had sharp angulation of the femora and humeri, distinctive facial features, and neonatal respiratory distress. Short stature was observed in three individuals. Three developed postnatal osteoporosis with subsequent fractures, two showed brachycephaly, and two were diagnosed with optic atrophy. Our findings suggest that heterozygous KIF5B deleterious variants cause a specific form of kyphomelic dysplasia. Furthermore, alterations in kinesins cause various symptoms known as kinesinopathies, and our findings also extend the phenotypic spectrum of kinesinopathies.
Assuntos
Anormalidades Múltiplas , Doenças do Desenvolvimento Ósseo , Nanismo , Cinesinas , Osteocondrodisplasias , Anormalidades Múltiplas/genética , Doenças do Desenvolvimento Ósseo/genética , Nanismo/diagnóstico , Nanismo/genética , Humanos , Recém-Nascido , Cinesinas/genética , Osteocondrodisplasias/diagnóstico , Osteocondrodisplasias/genéticaRESUMO
BACKGROUND: Pulmonary sarcomatoid carcinoma (PSC) is a rare and unconventional non-small-cell lung cancer (NSCLC) that appears to be aggressive, with a poor prognosis and response to conventional treatment. Approximately 30% of PSCs have potentially targetable genomic alterations, but few studies have involved RET gene fusions, and corresponding targeted therapies are lacking. CASE PRESENTATION: In this report, we describe a patient with PSC harboring a KIF5B-RET gene fusion who was initially diagnosed with stage IVb lung cancer. Due to the poor performance status, the patient was unable to tolerate any radiotherapy or chemotherapy. Based on the next-generation sequencing (NGS) result of RET gene fusion, the patient was treated with pralsetinib. Two months after the treatment, the patient achieved a partial response. CONCLUSIONS: Our case indicates that RET is one of the main driver oncogenes of PSC and provides useful information for precise RET inhibitor administration in the future. Thus, the use of comprehensive genomic profiling may provide important treatment options for PSC.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Carcinoma , Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/uso terapêutico , Proteínas Proto-Oncogênicas c-ret/genética , Proteínas Proto-Oncogênicas c-ret/uso terapêuticoRESUMO
AIMS: Histiocytoses are a heterogeneous group of localized or disseminated diseases. Clinical presentation and patients' outcome vary greatly, ranging from mild to life-threatening disorders. Rare cases of systemic or localized histiocytosis harboring ALK rearrangement have been reported. METHODS: Two cases of CNS histiocytosis were thoroughly investigated by implementing multiple molecular tests, i.e. FISH, RT-qPCR, NGS analysis. RESULTS: In a 10-month old girl (patient #1), MRI showed two left hemispheric lesions and a right fronto-mesial lesion histologically consisting of a moderately cellular infiltrative proliferation, composed by CD68(PGM1)+/CD163+ spindle cells. ALK 5'/3'-imbalance and a KIF5B(exon 24)-ALK(exon 20) fusion were documented by RT-qPCR and NGS analysis, respectively. A subsequent CT scan showed multiple hepatic and pulmonary lesions. The patient was started on chemotherapy (vinblastine) associated to an ALK-inhibitor (Alectinib) with remarkable response. In a 11-year-old girl (patient #2), MRI showed a right frontal 1.5 cm lesion. Neuropathological examination revealed a histiocytic proliferation composed by medium sized CD68(PGM1)+/HLA-DR+ cells, showing moderate ALK1 positivity. ALK rearrangement and a KIF5B(exon 24)-ALK(exon 20) fusion were demonstrated also in this case. Subsequent CT, 18F-FDG-PET and MRI scans showed the presence of a single right femoral lesion, proved to be a fibrous cortical defect. CONCLUSIONS: In ALK-histiocytoses, CNS involvement may occur as part of a systemic disease or, rarely, as its only primary disease localization, which could remain otherwise asymptomatic. The diagnosis often relies on neuropathological examination of brain biopsy, which may pose a diagnostic challenge due to the variable histopathological features. An integrated histological and molecular approach in such cases is recommended.
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Quinase do Linfoma Anaplásico/metabolismo , Sistema Nervoso Central/patologia , Histiocitose/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Biópsia/métodos , Sistema Nervoso Central/efeitos dos fármacos , Criança , Feminino , Histiocitose/diagnóstico , Histiocitose/patologia , Humanos , Lactente , Receptores Proteína Tirosina Quinases/efeitos dos fármacos , Receptores Proteína Tirosina Quinases/metabolismoRESUMO
RET is a transmembrane growth factor receptor. Aberrantly activated RET is found in several types of human cancer and is a target for treating RET aberration-associated cancer. Multiple clinically relevant RET protein-tyrosine kinase inhibitors (TKIs) have been identified, but how TKIs bind to RET is unknown except for vandetanib. Nintedanib is a RET TKI that inhibits the vandetanib-resistant RET(G810A) mutant. Here, we determined the X-ray co-crystal structure of RET kinase domain-nintedanib complex to 1.87 Å resolution and a RET(G810A) kinase domain crystal structure to 1.99 Å resolution. We also identified a vandetanib-resistant RET(L881V) mutation previously found in familial medullary thyroid carcinoma. Drug-sensitivity profiling of RET(L881V) revealed that it remains sensitive to nintedanib. The RET-nintedanib co-crystal structure disclosed that Leu-730 in RET engages in hydrophobic interactions with the piperazine, anilino, and phenyl groups of nintedanib, providing a structural basis for explaining that the p.L730V mutation identified in nine independently isolated cell lines resistant to nintedanib. Comparisons of RET-nintedanib, RET(G810A), and RET-vandetanib crystal structures suggested that the solvent-front Ala-810 makes hydrophobic contacts with a methyl group and aniline in nintedanib and blocks water access to two oxygen atoms of vandetanib, resulting in an energetic penalty for burying polar groups. Of note, even though the p.L881V mutation did not affect sensitivity to nintedanib, RET(L881V) was resistant to nintedanib analogs lacking a phenyl group. These results provide structural insights into resistance of RET mutants against the TKIs nintedanib and vandetanib.
Assuntos
Indóis/química , Piperidinas/química , Inibidores de Proteínas Quinases/química , Proteínas Proto-Oncogênicas c-ret/química , Quinazolinas/química , Animais , Sítios de Ligação , Linhagem Celular Tumoral , Cristalografia por Raios X , Resistencia a Medicamentos Antineoplásicos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Indóis/metabolismo , Camundongos , Simulação de Dinâmica Molecular , Mutagênese Sítio-Dirigida , Piperidinas/metabolismo , Inibidores de Proteínas Quinases/metabolismo , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-ret/genética , Proteínas Proto-Oncogênicas c-ret/metabolismo , Quinazolinas/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/genéticaRESUMO
Keratin intermediate filaments (IFs) are the major cytoskeletal component in epithelial cells. The dynamics of keratin IFs have been described to depend mostly on the actin cytoskeleton, but the rapid transport of fully polymerized keratin filaments has not been reported. In this work, we used a combination of photoconversion experiments and clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeats-associated protein 9 genome editing to study the role of microtubules and microtubule motors in keratin filament transport. We found that long keratin filaments, like other types of IFs, are transported along microtubules by kinesin-1. Our data revealed that keratin and vimentin are nonconventional kinesin-1 cargoes because their transport did not require kinesin light chains, which are a typical adapter for kinesin-dependent cargo transport. Furthermore, we found that the same domain of the kinesin heavy chain tail is involved in keratin and vimentin IF transport, strongly suggesting that multiple types of IFs move along microtubules using an identical mechanism.-Robert, A., Tian, P., Adam, S. A., Kittisopikul, M., Jaqaman, K., Goldman, R. D., Gelfand, V. I. Kinesin-dependent transport of keratin filaments: a unified mechanism for intermediate filament transport.
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Filamentos Intermediários/metabolismo , Queratina-18/metabolismo , Queratina-8/metabolismo , Cinesinas/fisiologia , Microtúbulos/metabolismo , Epitélio Pigmentado da Retina/metabolismo , Vimentina/metabolismo , Citoesqueleto de Actina/metabolismo , Animais , Sistemas CRISPR-Cas , Células Cultivadas , Cinesinas/antagonistas & inibidores , Camundongos , Camundongos Knockout , Microscopia de FluorescênciaRESUMO
Autophagic lysosome reformation (ALR) is the terminal step of autophagy and is essential for maintaining lysosome homeostasis during autophagy. During ALR, tubules are extruded from autolysosomes, and small vesicles named proto-lysosomes, which are composed of lysosomal membrane components, are generated from these tubules. Eventually, proto-lysosomes mature into functional lysosomes. In this review, we will summarize recent progress in understanding the regulation, mechanisms and physiological functions of ALR.
Assuntos
Autofagia/fisiologia , Membrana Celular/metabolismo , Homeostase/fisiologia , Lisossomos/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Animais , Clatrina/metabolismo , HumanosRESUMO
The androgen receptor (AR) is a ligand-activated nuclear receptor that plays a critical role in normal prostate physiology, as well as in the development and progression of prostate cancer. In addition to the classical paradigm in which AR exerts its biological effects in the nucleus by orchestrating the expression of the androgen-regulated transcriptome, there is considerable evidence supporting a rapid, nongenomic activity mediated by membrane-associated AR. Although the genomic action of AR has been studied in depth, the molecular events governing AR transport to the plasma membrane and the downstream AR signaling cascades remain poorly understood. In this study, we report that AR membrane transport is microtubule-dependent. Disruption of the function of kinesin 5B (KIF5B), but not of kinesin C3 (KIFC3), interfered with AR membrane association and signaling. Co-immunoprecipitation and pulldown assays revealed that AR physically interacts with KIF5B and that androgen enhances this interaction. Furthermore, we show that heat shock protein 27 (HSP27) is activated by membrane-associated AR and that HSP27 plays an important role in mediating AR-mediated membrane-to-nuclear signal transduction. Together, these results indicate that AR membrane translocation is mediated by the microtubule cytoskeleton and the motor protein KIF5B. By activating HSP27, membrane-associated AR potentiates the transcriptional activity of nuclear AR. We conclude that disruption of AR membrane translocation may represent a potential strategy for targeting AR signaling therapeutically in prostate cancer.
Assuntos
Membrana Celular/metabolismo , Regulação Neoplásica da Expressão Gênica , Proteínas de Choque Térmico HSP27/metabolismo , Cinesinas/metabolismo , Neoplasias da Próstata/metabolismo , Receptores Androgênicos/metabolismo , Transcrição Gênica , Proteínas de Choque Térmico HSP27/genética , Proteínas de Choque Térmico , Humanos , Cinesinas/genética , Masculino , Microtúbulos/metabolismo , Chaperonas Moleculares , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Transporte Proteico , Receptores Androgênicos/genética , Células Tumorais CultivadasRESUMO
The process of locomotion is controlled by fine-tuned dopaminergic neurons in the Substantia Nigra pars-compacta (SNpc) that projects their axons to the dorsal striatum regulating cortical innervations of medium spiny neurons. Dysfunction in dopaminergic neurotransmission within the striatum leads to movement impairments, gaiting defects, and hypo-locomotion. Due to their high polarity and extreme axonal arborization, neurons depend on molecular motor proteins and microtubule-based transport for their normal function. Transport defects have been associated with neurodegeneration since axonopathies, axonal clogging, microtubule destabilization, and lower motor proteins levels were described in the brain of patients with Parkinson's Disease and other neurodegenerative disorders. However, the contribution of specific motor proteins to the regulation of the nigrostriatal network remains unclear. Here, we generated different conditional knockout mice for the kinesin heavy chain 5B subunit (Kif5b) of Kinesin-1 to unravel its contribution to locomotion. Interestingly, mice with neuronal Kif5b deletion showed hypo-locomotion, movement initiation deficits, and coordination impairments. High pressure liquid chromatography determined that dopamine (DA) metabolism is impaired in neuronal Kif5b-KO, while no dopaminergic cell loss was observed. However, the deletion of Kif5b only in dopaminergic neurons is not sufficient to induce locomotor defects. Noteworthy, pharmacological stimulation of DA release together with agonist or antagonist of DA receptors revealed selective D2-dependent movement initiation defects in neuronal Kif5b-KO. Finally, subcellular fractionation from striatum showed that Kif5b deletion reduced the amount of dopamine D2 receptor in synaptic plasma membranes. Together, these results revealed an important role for Kif5b in the modulation of the striatal network that is relevant to the overall locomotor response. OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/.
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Corpo Estriado/metabolismo , Neurônios Dopaminérgicos/metabolismo , Cinesinas/metabolismo , Locomoção/fisiologia , Receptores de Dopamina D2/metabolismo , Animais , Camundongos , Camundongos KnockoutRESUMO
Tumor-associated macrophages (TAMs) exert tumor-promoting effects. There have been reports that estrogen receptors (ERs) are expressed on the infiltrating macrophages of endometriosis, ovarian cancer and lung cancer. However, the role of ERs in macrophages is not well characterized. In this study, we identified that ER alpha (ERα) expression on the macrophages of human endometrial cancer was positively correlated with cancer progression. Conditioned medium from selective ERα agonist-treated M2 macrophages induced the epithelial to mesenchymal transition (EMT) in endometrial cancer cells. However, this effect can be inhibited by ERα antagonist. Here, we showed that macrophages ERα-engaged abundantly produced chemokine (C-C motif) ligand 18 (CCL18), and its expression promoted the invasion of endometrial cancer cells by activating the extracellular signal-regulated kinase 1/2 pathway, whereas suppressing CCL18 abrogated these effects. Furthermore, we identified that CCL18 derived from TAMs upregulated KIF5B expression to promote EMT via activating the PI3K/AKT/mTOR signaling pathway in endometrial cancer. Overall, our findings show how ERα-engaged infiltrating macrophages initiate chronic inflammation and promote the aggressive progression of endometrial cancer cells. ERα-positive TAMs act as drivers of endometrial cancer, which may become a potential therapeutic target.
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Neoplasias do Endométrio/imunologia , Transição Epitelial-Mesenquimal/imunologia , Receptor alfa de Estrogênio/metabolismo , Macrófagos/imunologia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Quimiocinas CC/metabolismo , Neoplasias do Endométrio/patologia , Receptor alfa de Estrogênio/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Cinesinas/genética , Cinesinas/metabolismo , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismoRESUMO
Anoctamin 5 (ANO5)/TMEM16E belongs to a member of the ANO/TMEM16 family member of anion channels. However, it is a matter of debate whether ANO5 functions as a genuine plasma membrane chloride channel. It has been recognized that mutations in the ANO5 gene cause many skeletal muscle diseases such as limb girdle muscular dystrophy type 2L (LGMD2L) and Miyoshi muscular dystrophy type 3 (MMD3) in human. However, the molecular mechanisms of the skeletal myopathies caused by ANO5 defects are poorly understood. To understand the role of ANO5 in skeletal muscle development and function, we silenced the ANO5 gene in C2C12 myoblasts and evaluated whether it impairs myogenesis and myotube function. ANO5 knockdown (ANO5-KD) by shRNA resulted in clustered or aggregated nuclei at the body of myotubes without affecting differentiation or myotube formation. Nuclear positioning defect of ANO5-KD myotubes was accompanied with reduced expression of Kif5b protein, a kinesin-related motor protein that controls nuclear transport during myogenesis. ANO5-KD impaired depolarization-induced [Ca2+]i transient and reduced sarcoplasmic reticulum (SR) Ca2+ storage. ANO5-KD resulted in reduced protein expression of the dihydropyridine receptor (DHPR) and SR Ca2+-ATPase subtype 1. In addition, ANO5-KD compromised co-localization between DHPR and ryanodine receptor subtype 1. It is concluded that ANO5-KD causes nuclear positioning defect by reduction of Kif5b expression, and compromises Ca2+ signaling by downregulating the expression of DHPR and SERCA proteins.
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Cardiac hypertrophy is associated with growth and functional changes of cardiomyocytes, including mitochondrial alterations, but the latter are still poorly understood. Here we investigated mitochondrial function and dynamic localization in neonatal rat ventricular cardiomyocytes (NRVCs) stimulated with insulin like growth factor 1 (IGF1) or phenylephrine (PE), mimicking physiological and pathological hypertrophic responses, respectively. A decreased activity of the mitochondrial electron transport chain (ETC) (state 3) was observed in permeabilized NRVCs stimulated with PE, whereas this was improved in IGF1 stimulated NRVCs. In contrast, in intact NRVCs, mitochondrial oxygen consumption rate (OCR) was increased in PE stimulated NRVCs, but remained constant in IGF1 stimulated NRVCs. After stimulation with PE, mitochondria were localized to the periphery of the cell. To study the differences in more detail, we performed gene array studies. IGF1 and PE stimulated NRVCs did not reveal major differences in gene expression of mitochondrial encoding proteins, but we identified a gene encoding a motor protein implicated in mitochondrial localization, kinesin family member 5b (Kif5b), which was clearly elevated in PE stimulated NRVCs but not in IGF1 stimulated NRVCs. We confirmed that Kif5b gene and protein expression were elevated in animal models with pathological cardiac hypertrophy. Silencing of Kif5b reverted the peripheral mitochondrial localization in PE stimulated NRVCs and diminished PE induced increases in mitochondrial OCR, indicating that KIF5B dependent localization affects cellular responses to PE stimulated NRVCs. These results indicate that KIF5B contributes to mitochondrial localization and function in cardiomyocytes and may play a role in pathological hypertrophic responses in vivo.
Assuntos
Cardiomegalia/genética , Cardiomegalia/metabolismo , Cinesinas/genética , Mitocôndrias Cardíacas/genética , Mitocôndrias Cardíacas/metabolismo , Miócitos Cardíacos/metabolismo , Animais , Animais Recém-Nascidos , Respiração Celular , Células Cultivadas , Modelos Animais de Doenças , Complexo I de Transporte de Elétrons/metabolismo , Complexo II de Transporte de Elétrons/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Fator de Crescimento Insulin-Like I/genética , Fator de Crescimento Insulin-Like I/metabolismo , Cinesinas/metabolismo , Masculino , Mitocôndrias Cardíacas/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Biogênese de Organelas , Fenilefrina/farmacologia , RatosRESUMO
The regulation of cell-cell adhesion is important for the processes of tissue formation and morphogenesis. Here, we report that loss of 14-3-3γ leads to a decrease in cell-cell adhesion and a defect in the transport of plakoglobin and other desmosomal proteins to the cell border in HCT116 cells and cells of the mouse testis. 14-3-3γ binds to plakoglobin in a PKCµ-dependent fashion, resulting in microtubule-dependent transport of plakoglobin to cell borders. Transport of plakoglobin to the border is dependent on the KIF5B-KLC1 complex. Knockdown of KIF5B in HCT116 cells, or in the mouse testis, results in a phenotype similar to that observed upon 14-3-3γ knockdown. Our results suggest that loss of 14-3-3γ leads to decreased desmosome formation and a decrease in cell-cell adhesion in vitro, and in the mouse testis in vivo, leading to defects in testis organization and spermatogenesis.
Assuntos
Proteínas 14-3-3/metabolismo , Desmossomos/metabolismo , gama Catenina/metabolismo , Animais , Transporte Biológico , Adesão Celular/fisiologia , Células HCT116 , Humanos , Técnicas In Vitro , Infertilidade Masculina/metabolismo , Cinesinas , Masculino , CamundongosRESUMO
Insulin stimulates adiponectin secretion and glucose transporter type 4 (GLUT4) translocation in adipocyte to regulate metabolism homeostasis. Similar to GLUT4 translocation, intracellular trafficking and release of adiponectin in adipocytes relies on the trans-Golgi network and endosomal system. Recent studies show that the heavy chain of conventional kinesin (KIF5B) mediates GLUT4 translocation in murine 3T3-L1 adipocytes, however, the motor machinery involved in mediating intracellular trafficking and release of adiponectin is unknown. Here, we examined the role of KIF5B in the regulation of adiponectin secretion. The KIF5B level was up-regulated during 3T3-L1 adipogenesis. This increase in cytosolic KIF5B was synchronized with the induction of adiponectin. Endogenous KIF5B and adiponectin were partially colocalized at the peri-nuclear and cytosolic regions. In addition, adiponectin-containing vesicles were co-immunoprecipitated with KIF5B. Knockdown of KIF5B resulted in a marked inhibition of adiponectin secretion and overexpression of KIF5B enhanced adiponectin release, whereas leptin secretion was not affected by changes in KIF5B expression. These data suggest that the secretion of adiponectin, but not leptin, is dependent on functional KIF5B.
Assuntos
Adipócitos/metabolismo , Adiponectina/metabolismo , Cinesinas/metabolismo , Células 3T3-L1 , Transporte Ativo do Núcleo Celular , Adipócitos/citologia , Adipogenia/genética , Adipogenia/fisiologia , Adiponectina/genética , Animais , Diferenciação Celular , Técnicas de Silenciamento de Genes , Transportador de Glucose Tipo 4/metabolismo , Cinesinas/genética , Leptina/genética , Leptina/metabolismo , CamundongosRESUMO
Polarization of epithelial cells requires vectorial sorting and transport of polarity proteins to apical or basolateral domains. Kif5b is the mouse homologue of the human ubiquitous Kinesin Heavy Chain (uKHC). To investigate the function of Kif5b in epithelial cells, we examined the phenotypes of Kif5b-deficient MDCK cells. Stable knockdown of Kif5b in MDCK cells resulted in reduced cell proliferation rate, profound changes in cell morphology, loss of epithelial cell marker, and gain of mesenchymal marker, as well as increased cell migration, invasion, and tumorigenesis abilities. E-cadherin and NMMIIA could interact with Kif5b in polarized MDCK cells, and their expression levels were decreased in Kif5b-deficient MDCK cells. Overexpression of E-cadherin and NMMIIA in Kif5b depleted MDCK cells could decrease mesenchymal marker expression and cell migration ability. These results indicate that stable knockdown of Kif5b in MDCK cells can lead to epithelial-mesenchymal transition, which is mediated by defective E-cadherin and NMMIIA expression.
Assuntos
Transição Epitelial-Mesenquimal/fisiologia , Cinesinas/deficiência , Animais , Caderinas/metabolismo , Ciclo Celular , Linhagem Celular , Polaridade Celular/genética , Polaridade Celular/fisiologia , Proliferação de Células , Cães , Transição Epitelial-Mesenquimal/genética , Técnicas de Silenciamento de Genes , Humanos , Cinesinas/antagonistas & inibidores , Cinesinas/genética , Células Madin Darby de Rim Canino , Camundongos , Camundongos Nus , Cadeias Pesadas de Miosina/metabolismo , Metástase NeoplásicaAssuntos
Encefalopatias/genética , Histiocitose/genética , Proteínas de Neoplasias/genética , Proteínas de Fusão Oncogênica/genética , Encefalopatias/complicações , Encefalopatias/diagnóstico por imagem , Encefalopatias/cirurgia , Doenças Cerebelares/diagnóstico por imagem , Doenças Cerebelares/genética , Doenças Cerebelares/cirurgia , Neoplasias Cerebelares/diagnóstico , Criança , Diagnóstico Diferencial , Feminino , Células Espumosas/patologia , Histiocitose/complicações , Histiocitose/diagnóstico por imagem , Histiocitose/cirurgia , Humanos , Imageamento por Ressonância Magnética , Meduloblastoma/diagnóstico , Proteínas de Neoplasias/análise , Neuroimagem , Proteínas de Fusão Oncogênica/análise , Convulsões/etiologiaRESUMO
Foot-and-mouth disease (FMD) is a highly contagious and economically important disease, which is caused by the FMD virus (FMDV). Although the cell receptor for FMDV has been identified, the specific mechanism of FMDV internalization after infection remains unknown. In this study, we found that kinesin family member 5B (KIF5B) plays a vital role during FMDV internalization. Moreover, we confirmed the interaction between KIF5B and FMDV structural protein VP1 by co-immunoprecipitation (Co-IP) and co-localization in FMDV-infected cells. In particular, the stalk [amino acids (aa) 413-678] domain of KIF5B was indispensable for KIF5B-VP1 interaction. Moreover, overexpression of KIF5B dramatically enhanced FMDV replication; consistently, knockdown or knockout of KIF5B suppressed FMDV replication. Furthermore, we also demonstrated that KIF5B promotes the internalization of FMDV via regulating clathrin uncoating. KIF5B also promotes the transmission of viral particles to early and late endosomes during the early stages of infection. In conclusion, our results demonstrate that KIF5B promotes the internalization of FMDV via regulating clathrin uncoating and intracellular transport. This study may provide a new therapeutic target for developing FMDV antiviral drugs.
Assuntos
Vírus da Febre Aftosa , Cinesinas , Internalização do Vírus , Replicação Viral , Cinesinas/metabolismo , Cinesinas/genética , Vírus da Febre Aftosa/fisiologia , Vírus da Febre Aftosa/genética , Vírus da Febre Aftosa/metabolismo , Animais , Febre Aftosa/virologia , Febre Aftosa/metabolismo , Proteínas do Capsídeo/metabolismo , Proteínas do Capsídeo/genética , Linhagem Celular , Humanos , Endossomos/metabolismo , Endossomos/virologia , Células HEK293RESUMO
Anaplastic lymphoma kinase-positive histiocytosis, first reported in 2008, is a rare, novel type of neoplasm. To date, no more than 100 cases of anaplastic lymphoma kinase-positive histiocytosis have been reported. In this retrospective study, 12 cases of anaplastic lymphoma kinase-positive histiocytosis, including clinical symptoms, histological features, molecular pathology, treatment, and prognosis, in children were analyzed to gain a deeper understanding of the disease. All patients were Asian children, aged 2 months to 8 years and 2 months (mean 3.1 years), and the male-to-female ratio was 5:7. All patients were followed up closely. One patient died during the follow-up period, seven (case 1-7) had focal anaplastic lymphoma kinase-positive histiocytosis, and five (case 8-12) had multisystem anaplastic lymphoma kinase-positive histiocytosis. In addition, we report the case of a patient who benefited from anaplastic lymphoma kinase-targeted therapy and a patient with the rare EML4-ALK fusion gene. The current study is expected to substantially contribute to increasing the awareness of anaplastic lymphoma kinase-positive histiocytosis.