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1.
Int J Mol Sci ; 22(19)2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34638607

RESUMO

Asymmetric cell division (ACD) of neural stem cells and progenitors not only renews the stem cell population but also ensures the normal development of the nervous system, producing various types of neurons with different shapes and functions in the brain. One major mechanism to achieve ACD is the asymmetric localization and uneven segregation of intracellular proteins and organelles into sibling cells. Recent studies have demonstrated that liquid-liquid phase separation (LLPS) provides a potential mechanism for the formation of membrane-less biomolecular condensates that are asymmetrically distributed on limited membrane regions. Moreover, mechanical forces have emerged as pivotal regulators of asymmetric neural stem cell division by generating sibling cell size asymmetry. In this review, we will summarize recent discoveries of ACD mechanisms driven by LLPS and mechanical forces.


Assuntos
Divisão Celular Assimétrica/fisiologia , Células-Tronco Neurais/citologia , Células-Tronco Neurais/fisiologia , Animais , Fenômenos Biomecânicos , Divisão Celular/fisiologia , Polaridade Celular/fisiologia , Tamanho Celular , Proteínas de Drosophila/fisiologia , Drosophila melanogaster/citologia , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/fisiologia , Modelos Neurológicos , Miosinas/fisiologia , Neurogênese/fisiologia , Organelas/fisiologia
2.
PLoS Genet ; 17(10): e1009856, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34673778

RESUMO

The conserved adapter protein Scribble (Scrib) plays essential roles in a variety of cellular processes, including polarity establishment, proliferation, and directed cell migration. While the mechanisms through which Scrib promotes epithelial polarity are beginning to be unraveled, its roles in other cellular processes including cell migration remain enigmatic. In C. elegans, the Scrib ortholog LET-413 is essential for apical-basal polarization and junction formation in embryonic epithelia. However, whether LET-413 is required for postembryonic development or plays a role in migratory events is not known. Here, we use inducible protein degradation to investigate the functioning of LET-413 in larval epithelia. We find that LET-413 is essential in the epidermal epithelium for growth, viability, and junction maintenance. In addition, we identify a novel role for LET-413 in the polarized outgrowth of the epidermal seam cells. These stem cell-like epithelial cells extend anterior and posterior directed apical protrusions in each larval stage to reconnect to their neighbors. We show that the role of LET-413 in seam cell outgrowth is likely mediated largely by the junctional component DLG-1 discs large, which we demonstrate is also essential for directed outgrowth of the seam cells. Our data uncover multiple essential functions for LET-413 in larval development and show that the polarized outgrowth of the epithelial seam cells is controlled by LET-413 Scribble and DLG-1 Discs large.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Células Epidérmicas/metabolismo , Epiderme/metabolismo , Células Epiteliais/metabolismo , Animais , Polaridade Celular/fisiologia , Epitélio/metabolismo , Junções Intercelulares/metabolismo
3.
Development ; 148(19)2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34608934

RESUMO

Huntington's disease (HD) is a fatal neurodegenerative disorder caused by an expansion of the CAG repeats in the huntingtin gene (HTT). Although HD has been shown to have a developmental component, how early during human embryogenesis the HTT-CAG expansion can cause embryonic defects remains unknown. Here, we demonstrate a specific and highly reproducible CAG length-dependent phenotypic signature in a synthetic model for human gastrulation derived from human embryonic stem cells (hESCs). Specifically, we observed a reduction in the extension of the ectodermal compartment that is associated with enhanced activin signaling. Surprisingly, rather than a cell-autonomous effect, tracking the dynamics of TGFß signaling demonstrated that HTT-CAG expansion perturbs the spatial restriction of activin response. This is due to defects in the apicobasal polarization in the context of the polarized epithelium of the 2D gastruloid, leading to ectopic subcellular localization of TGFß receptors. This work refines the earliest developmental window for the prodromal phase of HD to the first 2 weeks of human development, as modeled by our 2D gastruloids.


Assuntos
Linhagem da Célula , Polaridade Celular , Camadas Germinativas/metabolismo , Células-Tronco Embrionárias Humanas/metabolismo , Proteína Huntingtina/metabolismo , Ativinas/metabolismo , Animais , Linhagem Celular , Células Cultivadas , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Camadas Germinativas/citologia , Camadas Germinativas/embriologia , Células-Tronco Embrionárias Humanas/citologia , Humanos , Proteína Huntingtina/genética , Camundongos , Transdução de Sinais , Fator de Crescimento Transformador beta/metabolismo , Expansão das Repetições de Trinucleotídeos
4.
Elife ; 102021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34596529

RESUMO

In multiple cell lineages, Delta-Notch signalling regulates cell fate decisions owing to unidirectional signalling between daughter cells. In Drosophila pupal sensory organ lineage, Notch regulates the intra-lineage pIIa/pIIb fate decision at cytokinesis. Notch and Delta that localise apically and basally at the pIIa-pIIb interface are expressed at low levels and their residence time at the plasma membrane is in the order of minutes. How Delta can effectively interact with Notch to trigger signalling from a large plasma membrane area remains poorly understood. Here, we report that the signalling interface possesses a unique apico-basal polarity with Par3/Bazooka localising in the form of nano-clusters at the apical and basal level. Notch is preferentially targeted to the pIIa-pIIb interface, where it co-clusters with Bazooka and its cofactor Sanpodo. Clusters whose assembly relies on Bazooka and Sanpodo activities are also positive for Neuralized, the E3 ligase required for Delta activity. We propose that the nano-clusters act as snap buttons at the new pIIa-pIIb interface to allow efficient intra-lineage signalling.


Assuntos
Divisão Celular , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Membrana/metabolismo , Receptores Notch/metabolismo , Órgãos dos Sentidos/metabolismo , Células-Tronco/metabolismo , Animais , Animais Geneticamente Modificados , Linhagem da Célula , Polaridade Celular , Citocinese , Proteínas de Drosophila/genética , Drosophila melanogaster/citologia , Drosophila melanogaster/genética , Regulação da Expressão Gênica no Desenvolvimento , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas de Membrana/genética , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Receptores Notch/genética , Órgãos dos Sentidos/citologia , Transdução de Sinais , Fatores de Tempo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
5.
Int J Mol Sci ; 22(17)2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34502237

RESUMO

Neural crest (NC) cells are highly migratory cells that contribute to various vertebrate tissues, and whose migratory behaviors resemble cancer cell migration and invasion. Information exchange via dynamic NC cell-cell contact is one mechanism by which the directionality of migrating NC cells is controlled. One transmembrane protein that is most likely involved in this process is protein tyrosine kinase 7 (PTK7), an evolutionary conserved Wnt co-receptor that is expressed in cranial NC cells and several tumor cells. In Xenopus, Ptk7 is required for NC migration. In this study, we show that the Ptk7 protein is dynamically localized at cell-cell contact zones of migrating Xenopus NC cells and required for contact inhibition of locomotion (CIL). Using deletion constructs of Ptk7, we determined that the extracellular immunoglobulin domains of Ptk7 are important for its transient accumulation and that they mediate homophilic binding. Conversely, we found that ectopic expression of Ptk7 in non-NC cells was able to prevent NC cell invasion. However, deletion of the extracellular domains of Ptk7 abolished this effect. Thus, Ptk7 is sufficient at protecting non-NC tissue from NC cell invasion, suggesting a common role of PTK7 in contact inhibition, cell invasion, and tissue integrity.


Assuntos
Moléculas de Adesão Celular/metabolismo , Diferenciação Celular , Movimento Celular , Inibição de Contato , Neoplasias Pulmonares/metabolismo , Crista Neural/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Animais , Polaridade Celular , Humanos , Neoplasias Pulmonares/patologia , Xenopus laevis
6.
Development ; 148(17)2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34473243

RESUMO

CPEB proteins are conserved translation regulators involved in multiple biological processes. One of these proteins in Drosophila, Orb2, is a principal player in spermatogenesis. It is required for meiosis and spermatid differentiation. During the later process, orb2 mRNA and protein are localized within the developing spermatid. To evaluate the role of the orb2 mRNA 3'UTR in spermatogenesis, we used the CRISPR/Cas9 system to generate a deletion of the orb2 3'UTR, orb2R. This deletion disrupts the process of spermatid differentiation but has no apparent effect on meiosis. Differentiation abnormalities include defects in the initial polarization of the 64-cell spermatid cysts, mislocalization of mRNAs and proteins in the elongating spermatid tails, altered morphology of the elongating spermatid tails, and defects in the assembly of the individualization complex. These disruptions in differentiation appear to arise because orb2 mRNA and protein are not properly localized within the 64-cell spermatid cyst.


Assuntos
Regiões 3' não Traduzidas , Proteínas de Drosophila/genética , Espermatogênese , Fatores de Transcrição/genética , Fatores de Poliadenilação e Clivagem de mRNA/genética , Animais , Diferenciação Celular , Polaridade Celular , Drosophila , Masculino , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Deleção de Sequência , Espermátides/citologia , Espermátides/metabolismo , Testículo/metabolismo
7.
Development ; 148(17)2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34499710

RESUMO

Cell polarity is fundamentally important for understanding brain development. Here, we hypothesize that the inheritance and flexibility of cell polarity during neocortex development could be implicated in neocortical evolutionary expansion. Molecular and morphological features of cell polarity may be inherited from one type of progenitor cell to the other and finally transmitted to neurons. Furthermore, key cell types, such as basal progenitors and neurons, exhibit a highly flexible polarity. We suggest that both inheritance and flexibility of cell polarity are implicated in the amplification of basal progenitors and tangential dispersion of neurons, which are key features of the evolutionary expansion of the neocortex.


Assuntos
Encéfalo/crescimento & desenvolvimento , Polaridade Celular/fisiologia , Animais , Encéfalo/citologia , Divisão Celular , Linhagem da Célula , Movimento Celular , Proliferação de Células , Humanos , Neocórtex/citologia , Neocórtex/crescimento & desenvolvimento , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Neurogênese , Neurônios/citologia , Neurônios/metabolismo
8.
Sci Rep ; 11(1): 17872, 2021 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-34504165

RESUMO

Cell polarity and morphogenesis are regulated by the small GTPase Cdc42. Even though major advances have been done in the field during the last years, the molecular details leading to its activation in particular cellular contexts are not completely understood. In fission yeast, the ß(1,3)-glucanase Eng2 is a "moonlighting protein" with a dual function, acting as a hydrolase during spore dehiscence, and as component of the endocytic machinery in vegetative cells. Here, we report that Eng2 plays a role in Cdc42 activation during polarized growth through its interaction with the scaffold protein Scd2, which brings Cdc42 together with its guanine nucleotide exchange factor (GEF) Scd1. eng2Δ mutant cells have defects in activation of the bipolar growth (NETO), remaining monopolar during all the cell cycle. In the absence of Eng2 the accumulation of Scd1 and Scd2 at the poles is reduced, the levels of Cdc42 activation decrease, and the Cdc42 oscillatory behavior, associated with bipolar growth in wild type cells, is altered. Furthermore, overexpression of Eng2 partially rescues the growth and polarity defects of a cdc42-L160S mutant. Altogether, our work unveils a new factor regulating the activity of Cdc42, which could potentially link the polarity and endocytic machineries.


Assuntos
Polaridade Celular/fisiologia , Retroalimentação , Proteínas de Schizosaccharomyces pombe/metabolismo , Proteína cdc42 de Ligação ao GTP/metabolismo , Proteínas de Ciclo Celular/metabolismo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Schizosaccharomyces/metabolismo
9.
PLoS One ; 16(9): e0257908, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34587205

RESUMO

In response to various stimuli, naïve macrophages usually polarize to M1 (classically activated) or M2 (alternatively activated) cells with distinct biological functions. Neuronal nitric oxide synthase (NOS1) is involved in M1 macrophage polarization at an early stage. Here, we show for the first time that NOS1 is dispensable for M2 macrophage polarization for the first time. Further, differentially expressed genes (DEGs) regulated by NOS1 signaling in M1-polarized macrophages stimulated with lipopolysaccharide (LPS) were characterized by transcriptome analysis of wild-type (WT) and NOS1 knockout mouse macrophages. Thousands of affected genes were detected 2 h post LPS challenge, and this wide-ranging effect became greater with a longer stimulation time (8 h post LPS). NOS1 deficiency caused dysregulated expression of hundreds of LPS-responsive genes. Most DEGs were enriched in biological processes related to transcription and regulation of the immune and inflammatory response. At 2 h post-LPS, the toll-like receptor (TLR) signaling pathway, cytokine-cytokine receptor interaction, and NOD-like receptor signaling pathway were the major pathways affected, whereas the main pathways affected at 8 h post-LPS were Th1 and Th2 cell differentiation, FoxO, and AMPK signaling pathway. Identified DEGs were validated by real-time quantitative PCR and interacted in a complicated signaling pathway network. Collectively, our data show that NOS1 is dispensable for M2 macrophage polarization and reveal novel insights in the role of NOS1 signaling at different stages of M1 macrophage polarization through distinct TLR4 plasma membrane-localized and endosome-internalized signaling pathways.


Assuntos
Perfilação da Expressão Gênica/métodos , Lipopolissacarídeos/efeitos adversos , Macrófagos/citologia , Óxido Nítrico Sintase Tipo I/genética , Animais , Polaridade Celular , Células Cultivadas , Feminino , Regulação da Expressão Gênica , Técnicas de Inativação de Genes , Ativação de Macrófagos , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Masculino , Camundongos , Análise de Sequência de RNA , Transdução de Sinais
10.
J Cell Biol ; 220(10)2021 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-34515738

RESUMO

Hepatocytes display a unique biaxial polarity with shared apical luminal connections between adjacent hepatocytes that merge into a network of bile canaliculi. Belicova et al. (2021. J. Cell Biol.https://doi.org/10.1083/jcb.202103003) discovered that hepatocyte apical membranes generate Rab35-dependent extensions that traverse the lumen and are essential for bile canalicular formation and maintenance.


Assuntos
Canalículos Biliares , Bile , Polaridade Celular , Hepatócitos , Morfogênese
11.
J Cell Sci ; 134(20)2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34528675

RESUMO

ATP11C, a member of the P4-ATPase family, translocates phosphatidylserine and phosphatidylethanolamine at the plasma membrane. We previously revealed that its C-terminal splice variant ATP11C-b exhibits polarized localization in motile cell lines, such as MDA-MB-231 and Ba/F3. In the present study, we found that the C-terminal cytoplasmic region of ATP11C-b interacts specifically with ezrin. Notably, the LLxY motif in the ATP11C-b C-terminal region is crucial for its interaction with ezrin as well as its polarized localization on the plasma membrane. A constitutively active, C-terminal phosphomimetic mutant of ezrin was colocalized with ATP11C-b in polarized motile cells. ATP11C-b was partially mislocalized in cells depleted of ezrin alone, and exhibited greater mislocalization in cells simultaneously depleted of the family members ezrin, radixin and moesin (ERM), suggesting that ERM proteins, particularly ezrin, contribute to the polarized localization of ATP11C-b. Furthermore, Atp11c knockout resulted in C-terminally phosphorylated ERM protein mislocalization, which was restored by exogenous expression of ATP11C-b but not ATP11C-a. These observations together indicate that the polarized localizations of ATP11C-b and the active form of ezrin to the plasma membrane are interdependently stabilized.


Assuntos
Adenosina Trifosfatases , Polaridade Celular , Membrana Celular , Citoplasma , Proteínas do Citoesqueleto , Fosfoproteínas
12.
Int J Mol Sci ; 22(17)2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34502566

RESUMO

The renal secretory clearance for organic cations (neurotransmitters, metabolism products and drugs) is mediated by transporters specifically expressed in the basolateral and apical plasma membrane domains of proximal tubule cells. Here, human organic cation transporter 2 (hOCT2) is the main transporter for organic cations in the basolateral membrane domain. In this study, we stably expressed hOCT2 in Madin-Darby Canine Kidney (MDCK) cells and cultivated these cells in the presence of an extracellular matrix to obtain three-dimensional (3D) structures (cysts). The transport properties of hOCT2 expressed in MDCK cysts were compared with those measured using human embryonic kidney cells (HEK293) stably transfected with hOCT2 (hOCT2-HEK cells). In the MDCK cysts, hOCT2 was expressed in the basolateral membrane domain and showed a significant uptake of the fluorescent organic cation 4-(4-(dimethylamino)styryl)-N-methylpyridinium (ASP+) with an affinity (Km) of 3.6 ± 1.2 µM, similar to what was measured in the hOCT2-HEK cells (Km = 3.1 ± 0.2 µM). ASP+ uptake was inhibited by tetraethylammonium (TEA+), tetrapentylammonium (TPA+), metformin and baricitinib both in the hOCT2-HEK cells and the hOCT2- MDCK cysts, even though the apparent affinities of TEA+ and baricitinib were dependent on the expression system. Then, hOCT2 was subjected to the same rapid regulation by inhibition of p56lck tyrosine kinase or calmodulin in the hOCT2-HEK cells and hOCT2- MDCK cysts. However, inhibition of casein kinase II regulated only activity of hOCT2 expressed in MDCK cysts and not in HEK cells. Taken together, these results suggest that the 3D cell culture model is a suitable tool for the functional analysis of hOCT2 transport properties, depending on cell polarization.


Assuntos
Técnicas de Cultura de Células/métodos , Polaridade Celular/fisiologia , Células Epiteliais/metabolismo , Transportador 2 de Cátion Orgânico/metabolismo , Animais , Transporte Biológico/fisiologia , Cátions/metabolismo , Cães , Células Epiteliais/citologia , Células Epiteliais/fisiologia , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Humanos , Células Madin Darby de Rim Canino , Metilaminas/metabolismo , Microscopia de Fluorescência/métodos , Transportador 2 de Cátion Orgânico/genética , Compostos de Piridínio/metabolismo
13.
Stem Cell Res Ther ; 12(1): 519, 2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34583757

RESUMO

BACKGROUND: Exosomes are considered a substitute for stem cell-based therapy for myocardial infarction (MI). FNDC5, a transmembrane protein located in the cytoplasm, plays a crucial role in inflammation diseases and MI repair. Furthermore, our previous study found that FNDC5 pre-conditioning bone marrow-derived mesenchymal stem cells (BMMSCs) could secrete more exosomes, but little was known on MI repair. METHODS: Exosomes isolated from BMMSCs with or without FNDC5-OV were injected into infarcted hearts. Then, cardiomyocytes apoptosis and inflammation responses were detected. Furthermore, exosomes were administrated to RAW264.7 macrophage with LPS treatment to investigate its effect on inflammation and macrophage polarization. RESULTS: Compared with MSCs-Exo, FNDC5-MSCs-Exo had superior therapeutic effects on anti-inflammation and anti-apoptosis, as well as polarizing M2 macrophage in vivo. Meanwhile, the in vitro results also showed that FNDC5-MSCs-Exo decreased pro-inflammatory secretion and increased anti-inflammatory secretion under LPS stimulation, which partly depressed NF-κB signaling pathway and upregulated Nrf2/HO-1 Axis. CONCLUSIONS: FNDC5-BMMSCs-derived exosomes play anti-inflammation effects and promote M2 macrophage polarization via NF-κB signaling pathway and Nrf2/HO-1 Axis, which may develop a promising cell-free therapy for MI.


Assuntos
Exossomos , Macrófagos , Células-Tronco Mesenquimais , Infarto do Miocárdio , Animais , Polaridade Celular , Fibronectinas/genética , Heme Oxigenase-1/genética , Inflamação , Proteínas de Membrana/genética , Camundongos , Infarto do Miocárdio/genética , Infarto do Miocárdio/terapia , Fator 2 Relacionado a NF-E2/genética , NF-kappa B/genética , Células RAW 264.7 , Transdução de Sinais
14.
Elife ; 102021 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-34569938

RESUMO

Apico-basal polarization of cells within the embryo is critical for the segregation of distinct lineages during mammalian development. Polarized cells become the trophectoderm (TE), which forms the placenta, and apolar cells become the inner cell mass (ICM), the founding population of the fetus. The cellular and molecular mechanisms leading to polarization of the human embryo and its timing during embryogenesis have remained unknown. Here, we show that human embryo polarization occurs in two steps: it begins with the apical enrichment of F-actin and is followed by the apical accumulation of the PAR complex. This two-step polarization process leads to the formation of an apical domain at the 8-16 cell stage. Using RNA interference, we show that apical domain formation requires Phospholipase C (PLC) signaling, specifically the enzymes PLCB1 and PLCE1, from the eight-cell stage onwards. Finally, we show that although expression of the critical TE differentiation marker GATA3 can be initiated independently of embryo polarization, downregulation of PLCB1 and PLCE1 decreases GATA3 expression through a reduction in the number of polarized cells. Therefore, apical domain formation reinforces a TE fate. The results we present here demonstrate how polarization is triggered to regulate the first lineage segregation in human embryos.


Assuntos
Padronização Corporal , Diferenciação Celular , Linhagem da Célula , Polaridade Celular , Embrião de Mamíferos/enzimologia , Actinas/metabolismo , Adulto , Técnicas de Cultura Embrionária , Feminino , Fator de Transcrição GATA3/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação Enzimológica da Expressão Gênica , Humanos , Fosfoinositídeo Fosfolipase C , Fosfolipase C beta , Gravidez , Transdução de Sinais , Fatores de Tempo , Adulto Jovem
15.
Dev Cell ; 56(18): 2579-2591.e4, 2021 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-34525342

RESUMO

Force generation in epithelial tissues is often pulsatile, with actomyosin networks generating contractile forces before cyclically disassembling. This pulsed nature of cytoskeletal forces implies that there must be ratcheting mechanisms that drive processive transformations in cell shape. Previous work has shown that force generation is coordinated with endocytic remodeling; however, how ratcheting becomes engaged at specific cell surfaces remains unclear. Here, we report that PtdIns(3,4,5)P3 is a critical lipid-based cue for ratcheting engagement. The Sbf RabGEF binds to PIP3, and disruption of PIP3 reveals a dramatic switching behavior in which medial ratcheting is activated and epithelial cells begin globally constricting apical surfaces. PIP3 enrichments are developmentally regulated, with mesodermal cells having high apical PIP3 while germband cells have higher interfacial PIP3. Finally, we show that JAK/STAT signaling constitutes a second pathway that combinatorially regulates Sbf/Rab35 recruitment. Our results elucidate a complex lipid-dependent regulatory machinery that directs ratcheting engagement in epithelial tissues.


Assuntos
Actomiosina/metabolismo , Forma Celular/fisiologia , Células Epiteliais/metabolismo , Morfogênese/fisiologia , Fosfatidilinositóis/metabolismo , Citoesqueleto de Actina/metabolismo , Animais , Membrana Celular/metabolismo , Polaridade Celular/fisiologia , Citoesqueleto/metabolismo , Drosophila , Proteínas de Drosophila/metabolismo , Epitélio/metabolismo
16.
Nat Commun ; 12(1): 4697, 2021 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-34349123

RESUMO

Polarized epithelial cells can organize into complex structures with a characteristic central lumen. Lumen formation requires that cells coordinately orient their polarity axis so that the basolateral domain is on the outside and apical domain inside epithelial structures. Here we show that the transmembrane aminopeptidase, CD13, is a key determinant of epithelial polarity orientation. CD13 localizes to the apical membrane and associates with an apical complex with Par6. CD13-deficient cells display inverted polarity in which apical proteins are retained on the outer cell periphery and fail to accumulate at an intercellular apical initiation site. Here we show that CD13 is required to couple apical protein cargo to Rab11-endosomes and for capture of endosomes at the apical initiation site. This role in polarity utilizes the short intracellular domain but is independent of CD13 peptidase activity.


Assuntos
Antígenos CD13/metabolismo , Polaridade Celular , Células Epiteliais/citologia , Epitélio/crescimento & desenvolvimento , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Antígenos CD13/química , Antígenos CD13/genética , Células CACO-2 , Membrana Celular/metabolismo , Endocitose , Endossomos/metabolismo , Células Epiteliais/metabolismo , Humanos , Proteínas de Membrana/metabolismo , Domínios Proteicos , Proteínas rab de Ligação ao GTP/metabolismo
17.
Biomed Res Int ; 2021: 3376496, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34337004

RESUMO

Lactobacillus rhamnoides, a human intestinal colonizer, can act through various pathways to induce microglia/macrophages to produce cytokines and to polarize microglia/macrophages to different phenotypes to reduce the inflammatory response. In this article, we evaluated the treatment potential of the Lactobacillus rhamnoides GG conditioned medium (LGG-CM) in rat model with SCI (acute spinal cord injury), including functional, neurophysiological, and histological outcomes and the underlying neuroprotective mechanisms. In our experiment, LGG-CM (30 mg/kg) was injected directly into the injury site in rats immediately after SCI. Measured by the BBB scale (Basso, Beattie, and Bresnahan locomotor rating scale) and inclined plane test, rats in the LGG-CM-treated group showed better locomotor scores. Moreover, compared to the vehicle treatment group, LGG-CM increased the mRNA level of the M2 marker (CD206), and decreased that of the M1 marker (iNOS). Western blot assays showed that LGG-CM-treated SCI rats had a higher grayscale ratio of p65 and a lower ratio of p-IκBα/IκBα. Our study shows that local injection of LGG-CM after acute SCI can inhibit inflammatory responses and improve motor function recovery. These effects may be related with the inhibition to the NF-κB (The nuclear factor-kappa B) signal pathway which leads to M2 microglia/macrophage polarization.


Assuntos
Polaridade Celular , Meios de Cultivo Condicionados/farmacologia , Lactobacillus rhamnosus/química , Macrófagos/patologia , Microglia/patologia , Recuperação de Função Fisiológica , Traumatismos da Medula Espinal/fisiopatologia , Animais , Polaridade Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Inflamação/patologia , Macrófagos/efeitos dos fármacos , Microglia/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Inibidor de NF-kappaB alfa/metabolismo , NF-kappa B/metabolismo , Fosforilação/efeitos dos fármacos , Ratos , Recuperação de Função Fisiológica/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
18.
Int J Mol Sci ; 22(16)2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34445510

RESUMO

Microglia are resident immune cells of the central nervous system that act as brain-specific macrophages and are also known to regulate the innate immune functions of astrocytes through secretory molecules. This communication plays an important role in brain functions and homeostasis as well as in neuropathologic disease. In this study, we aimed to elucidate whether astrocytes and microglia could crosstalk to induce microglial polarization and proliferation, which can be further regulated under a microenvironment mimicking that of brain stroke. Microglia in a mixed glial culture showed increased survival and proliferation and were altered to M2 microglia; CD11b-GFAP+ astrocytes resulted in an approximately tenfold increase in microglial cell proliferation after the reconstitution of astrocytes. Furthermore, GM-CSF stimulated microglial proliferation approximately tenfold and induced them to become CCR7+ M1 microglia, which have a phenotype that could be suppressed by anti-inflammatory cytokines such as IL-4, IL-10, and substance P. In addition, the astrocytes in the microglial co-culture showed an A2 phenotype; they could be activated to A1 astrocytes by TNF-α and IFN-γ under the stroke-mimicking condition. Altogether, astrocytes in the mixed glial culture stimulated the proliferation of the microglia and M2 polarization, possibly through the acquisition of the A2 phenotype; both could be converted to M1 microglia and A1 astrocytes under the inflammatory stroke-mimicking environment. This study demonstrated that microglia and astrocytes could be polarized to M2 microglia and A2 astrocytes, respectively, through crosstalk in vitro and provides a system with which to explore how microglia and astrocytes may behave in the inflammatory disease milieu after in vivo transplantation.


Assuntos
Astrócitos/citologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Macrófagos/citologia , Microglia/citologia , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/imunologia , Comunicação Celular , Polaridade Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Interleucina-10/metabolismo , Interleucina-4/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Microglia/efeitos dos fármacos , Microglia/imunologia , Ratos
19.
Phytomedicine ; 91: 153692, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34411834

RESUMO

PURPOSE: Magnolol (MA) exhibits anti-depressant effect by inhibiting inflammation. However, its effect on microglia polarization remains not fully understood. Herein, our study was performed to evaluate the effect of MA on microglia polarization in chronic unpredictable mild stress (CUMS)-induced depression and explore its potential mechanism. STUDY DESIGN: The CUMS procedure was conducted, and the mice were intragastrically treated with MA. BV2 cells were pretreated with MA prior to LPS/ATP challenge. METHODS: The levels of TNF-α, IL-1ß, IL-6 and IL-4, IL-10 in brain and BV2 cells were examined by ELISA. The mRNA expressions of Arg1, Ym1, Fizz1 and Klf4 in brains were measured. ROS content was determined using flow cytometry. Immunofluorescence was employed to evaluate Iba-1 level, Nrf2 nuclear translocation, Iba-1+CD16/32+ and Iba-1+CD206+ cell population. The protein expressions of Nrf2, HO-1, NLRP3, caspase-1 p20 and IL-1ß in brains and BV2 cells were investigated by western blot. Nrf2 siRNA was induced in experiments to explore the role of Nrf2 in MA-mediated microglia polarization. The ubiquitination of Nrf2 was visualized by Co-IP. RESULTS: The treatment with MA notably relieved depressive like behaviors, suppressed pro-inflammatory cytokines, promoted anti-inflammatory cytokines and the transcription of M2 phenotype microglia-specific indicators. MA upregulated the expression of Nrf2, HO-1, downregulated the expression of NLRP3, caspase-1 p20, IL-1ß both in vivo and in vitro. MA also reduced ROS concentration, promoted Nrf2 nucleus translocation and prevented Nrf2 ubiquitination. Nrf2 Knockdown by siRNA abolished the MA-mediated microglia polarization. CONCLUSION: The present research demonstrated that MA attenuated CUMS-stimulated depression by inhibiting M1 polarization and inducing M2 polarization via Nrf2/HO-1/NLRP3 signaling.


Assuntos
Compostos de Bifenilo/farmacologia , Depressão/tratamento farmacológico , Lignanas/farmacologia , Microglia , Transdução de Sinais/efeitos dos fármacos , Animais , Polaridade Celular , Heme Oxigenase-1 , Lipopolissacarídeos , Proteínas de Membrana , Camundongos , Microglia/citologia , Microglia/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR
20.
Life Sci ; 284: 119914, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34453949

RESUMO

Macrophages, an important part of human immune system, possess a high plasticity and heterogeneity (macrophage polarization) as classically activated macrophages (M1) and alternatively activated macrophages (M2), which exert pro-inflammatory/anti-tumor and anti-inflammatory/pro-tumor effects, respectively. Thus, drug development in induction of macrophage polarization could be used to treat different human diseases. This review summarizes the recent advancement on modulation of macrophage polarization and its related molecular mechanisms induced by a number of agents. Research on the anti-inflammatory drugs to regulate the macrophage polarization accounts for a large proportion in the field and types of diseases investigated could include atherosclerosis, enteritis, nephritis, and the nervous system and skeletal diseases, while study of the anti-tumor agents to modify macrophage polarization is a novel area of research. Future study of the molecular mechanisms by which the different agents regulate the macrophage polarization could lead to an effective control of various human diseases, including inflammation and cancers.


Assuntos
Polaridade Celular , Doença , Macrófagos/citologia , Preparações Farmacêuticas/metabolismo , Animais , Polaridade Celular/genética , Humanos , Macrófagos/metabolismo , Transdução de Sinais/genética
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