RESUMO
Triacylglycerol (TAG) is crucial for antibiotic biosynthesis derived from Streptomyces, as it serves as an important carbon source. In this study, the supplementation of exogenous TAG led to a 3.92-fold augmentation in spinosad production. The impact of exogenous TAG on the metabolic network of Saccharopolyspora spinosa were deeply analyzed through comparative proteomics. To optimize TAG metabolism and enhance spinosad biosynthesis, the lipase-encoding genes lip886 and lip385 were overexpressed or co-expressed. The results shown that the yield of spinosad was increased by 0.8-fold and 0.4-fold when lip886 and lip385 genes were overexpressed, respectively. Synergistic co-expression of these genes resulted in a 2.29-fold increase in the yield of spinosad. Remarkably, the combined overexpression of lip886 and lip385 in the presence of exogenous TAG elevated spinosad yields by 5.5-fold, led to a drastic increase in spinosad production from 0.036 g/L to 0.234 g/L. This study underscores the modification of intracellular concentrations of free fatty acids (FFAs), short-chain acyl-CoAs, ATP, and NADPH as mechanisms by which exogenous TAG modulates spinosad biosynthesis. Overall, the findings validate the enhancement of TAG catabolism as a beneficial strategy for optimizing spinosad production and provide foundational insights for engineering secondary metabolite biosynthesis pathways in another Streptomyces.
RESUMO
[This corrects the article on p. 370 in vol. 11, PMID: 33575077.].
RESUMO
AIM: Multiple sclerosis (MS) is an autoimmune disease, and its typical characteristics are neuroinflammation and the demyelination of neurons in the central nervous system (CNS). Sterile alpha and TIR motif containing 1 (SARM1) is an essential factor mediating axonal degeneration and SARM1 deletion reduces the neuroinflammation in spinal cord injury. This study aimed to explore the roles of SARM1 and its underlying mechanisms in MS. METHODS: Experimental autoimmune encephalomyelitis (EAE, a model of MS) model was established. Immunostaining, western blot, electron microscope, and HE staining were used to examine the pathological manifestations such as inflammation, demyelination, and neuronal death in SARM1f/f EAE mice and SARM1Nestin -CKO EAE mice. In addition, RNA-seq, real-time PCR and double-immunostaining were used to examine the underlying mechanism of SARM1 in EAE mice. RESULTS: SARM1 was upregulated in neurons of the spinal cords of EAE mice. SARM1 knockout in CNS ameliorated EAE with less neuroinflammation, demyelination, and dead neurons. Mechanically, SARM1 knockout resulted in the reduction of insulin-like growth factor (IGF)-binding protein 2 (IGFBP2) in neurons of EAE mice, which might inhibit the neuroinflammation through inhibiting NF-κB signaling. Finally, activation of NF-κB partially aggravated the neuroinflammation and demyelination deficits of SARM1Nestin -CKO EAE mice. CONCLUSIONS: These results identified the unknown role of SARM1 in the promotion of neuroinflammation and demyelination and revealed a novel drug target pathway of SARM1/IGFBP2/NF-κB for MS.
Assuntos
Encefalomielite Autoimune Experimental , Camundongos , Animais , Encefalomielite Autoimune Experimental/metabolismo , Encefalomielite Autoimune Experimental/patologia , NF-kappa B/metabolismo , Nestina , Doenças Neuroinflamatórias , Citocinas/metabolismo , Camundongos Endogâmicos C57BL , Proteínas do Citoesqueleto/genética , Proteínas do Domínio Armadillo/genéticaRESUMO
BACKGROUND: Cottonseed meal (CSM) is the main by-product of the cottonseed oil extraction process with high protein content, which is an important protein source for feed industry. However, CSM contains free gossypol (FG), a toxic substance that is detrimental to animal health and greatly limits its application. Microbial fermentation is currently considered to be one of the most effective methods to reduce FG and other anti-nutritional factors in CSM. Previously, yeast and bacteria species are used for degradation of FG in CSM, but showing less detoxification efficiency. Bacillus coagulans combines the properties of both lactic acid bacteria and Bacillus, producing both lactic acid and spores, and is considered a potential probiotic. In this study, we aimed to evaluate and optimize the effect of the solid-state fermentation process using a Bacillus coagulans to gossypol removal contained cottonseed meal. RESULTS: 36 B. coagulans strains were isolated and found to have the ability to remove free gossypol. Through the evaluation of strains and optimization of fermentation conditions including fermentation temperature, ratio of material to water, inoculation amount, fermentation time and pH, we have established a solid-state fermentation process using a Bacillus coagulans strain S17 on CSM substrate with 1:1 of the material-to-water ratio, 15% (v/w) seed inoculation, 2% expanded corn flour, 1% bran, and 0.3%-0.8% metal irons at 40 °C for 52 h. After fermentation, the FG content in CSM was reduced from 923.80 to 167.90 mg/kg with 81.83% detoxification efficiency. Meanwhile, the crude protein content in CSM increased from 47.98 to 52.82%, and importantly, the spore concentration of strain S17 reached 1.68 × 1010 CFU/g dry material. CONCLUSION: The study showed that B. coagulans have the potential strong ability to degrade free gossypol through cottonseed meal fermentation. This study presents a feasible process for improving the resource utilization rate and nutritional value of CSM via solid-state fermentation through B. coagulans S17.
Assuntos
Bacillus coagulans , Gossipol , Probióticos , Animais , Fermentação , Óleo de Sementes de Algodão , Saccharomyces cerevisiaeRESUMO
Developing cocatalyst-free photocatalysts is highly desired because it could avoid the very slow interfacial electron transfer that makes photocatalytic photon utilization a dilemma. However, even in the optimal case, photocatalysts without the use of cocatalysts deliver comparable performance only for conventional construction. We demonstrate here that electronic doping not only provides catalytically active sites in cocatalyst-free photocatalysts but also plays certain additional roles. These electronic states can efficiently channel the trapped electrons to the semiconductor surface without suffering from time-consuming detrapping and can facilitate the extraction of photogenerated holes. These features endow our demonstrated tungsten-doped CdS with evident superiority in photocatalytic performance over conventional counterparts loaded with platinum cocatalysts.
RESUMO
The horizontal basal cells (HBCs) of olfactory epithelium (OE) serve as reservoirs for stem cells during OE regeneration, through proliferation and differentiation, which is important in recovery of olfactory function. However, the molecular mechanism of regulation of HBC proliferation and differentiation after injury remains unclear. Here, we found that yes-associated protein (YAP) was upregulated and activated in HBCs after OE injury. Deletion of YAP in HBCs led to impairment in OE regeneration and functional recovery of olfaction after injury. Mechanically, YAP was activated by S1P/S1PR2 signaling, thereby promoting the proliferation of HBCs and OE regeneration after injury. Finally, activation of YAP signaling enhanced the proliferation of HBCs and improved functional recovery of olfaction after OE injury or in Alzheimer's disease model mice. Taken together, these results reveal an S1P/S1PR2/YAP pathway in OE regeneration in response to injury, providing a promising therapeutic strategy for OE injury.
Assuntos
Mucosa Olfatória , Células-Tronco , Animais , Diferenciação Celular/fisiologia , Camundongos , Transdução de Sinais , Células-Tronco/metabolismoRESUMO
Cholesterols are the main components of myelin, and are mainly synthesized in astrocytes and transported to oligodendrocytes and neurons in the adult brain. It has been reported that Hippo/yes-associated protein (YAP) pathways are involved in cholesterol synthesis in the liver, however, it remains unknown whether YAP signaling can prevent the demyelination through promoting cholesterol synthesis in experimental autoimmune encephalomyelitis (EAE), a commonly used animal model of multiple sclerosis characterized by neuroinflammation and demyelination. Here, we found that YAP was upregulated and activated in astrocytes of spinal cords of EAE mice through suppression of the Hippo pathway. YAP deletion in astrocytes aggravated EAE with earlier onset, severer inflammatory infiltration, demyelination, and more loss of neurons. Furthermore, we found that the neuroinflammation was aggravated and the proliferation of astrocytes was decreased in YAPGFAP-CKO EAE mice. Mechanically, RNA-seq revealed that the expression of cholesterol-synthesis pathway genes such as HMGCS1 were decreased in YAP-/- astrocytes. qPCR, western blot, and immunostaining further confirmed the more significant reduction of HMGCS1 in spinal cord astrocytes of YAPGFAP-CKO EAE mice. Interestingly, upregulation of cholesterol-synthesis pathways by diarylpropionitrile (DPN) (an ERß-ligand, to upregulate the expression of HMGCS1) treatment partially rescued the demyelination deficits in YAPGFAP-CKO EAE mice. Finally, activation of YAP by XMU-MP-1 treatment promoted the expression of HMGCS1 in astrocytes and partially rescued the demyelination and inflammatory infiltration deficits in EAE mice. These findings identify unrecognized functions of astrocytic YAP in the prevention of demyelination through promoting cholesterol synthesis in EAE, and reveal a novel pathway of YAP/HMGCS1 for cholesterol synthesis in EAE pathology.
Assuntos
Astrócitos/metabolismo , Colesterol/biossíntese , Doenças Desmielinizantes/genética , Encefalomielite Autoimune Experimental/genética , Regulação da Expressão Gênica , Animais , Astrócitos/patologia , Peso Corporal , Proliferação de Células , Regulação para Baixo/genética , Encefalomielite Autoimune Experimental/patologia , Encefalomielite Autoimune Experimental/fisiopatologia , Via de Sinalização Hippo , Inflamação/patologia , Camundongos Knockout , Modelos Biológicos , Neurônios/metabolismo , Neurônios/patologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Recuperação de Função Fisiológica , Medula Espinal/patologia , Medula Espinal/ultraestrutura , Regulação para Cima/genética , Proteínas de Sinalização YAP/deficiência , Proteínas de Sinalização YAP/metabolismoRESUMO
Microalgae is one of the most important components in the aquatic ecosystem, and they are increasingly used in food and medicine production for human consumption due to their rapid growth cycle and survival ability in the harsh environment. Now, the exploration of microalgae has been gradually deepening, mainly focused on the field of nutrition, medicine, and cosmetics. A great deal of studies has shown that microalgae have a variety of functions in regulating the body health and preventing disease, such as nitrogen fixation, antitumor, antivirus, antioxidation, anti-inflammatory, and antithrombotic. Furthermore, microalgae can synthesize various high-valued bioactive substances, such as proteins, lipids, polysaccharides, and pigments. In this paper, we have briefly reviewed the research progress of main bioactive components in microalgae, proteins, lipids, polysaccharides, pigments, and other nutrients included, as well as their present application situation. This paper can provide the guidance for research and development of industrial production of microalgae.
RESUMO
Rationale: Optic neuritis is one of main symptoms in multiple sclerosis (MS) that causes visual disability. Astrocytes are pivotal regulators of neuroinflammation in MS, and astrocytic yes-associated protein (YAP) plays a critical role in neuroinflammation. Meanwhile, YAP signaling is involved in visual impairment, including glaucoma, retinal choroidal atrophy and retinal detachment. However, the roles and underlying mechanisms of astrocytic YAP in neuroinflammation and demyelination of MS-related optic neuritis (MS-ON) remains unclear. Methods: To assess the functions of YAP in MS-ON, experimental autoimmune encephalomyelitis (EAE, a common model of MS) was established, and mice that conditional knockout (CKO) of YAP in astrocytes, YAPGFAP-CKO mice, were successfully generated. Behavior tests, immunostaining, Nissl staining, Hematoxylin-Eosin (HE) staining, TUNEL staining, Luxol Fast Blue (LFB) staining, electron microscopy (EM), quantitative real-time PCR (qPCR), gene set enrichment analysis (GSEA) and gene set variation analysis (GSVA) by RNA sequencing were used to examine the function and mechanism of YAP signaling based on these YAPGFAP-CKO mice and EAE model mice. To further explore the potential treatment of YAP signaling in EAE, EAE mice were treated with various drugs, including SRI-011381 that is an agonist of transforming growth factor-ß (TGF-ß) pathway, and XMU-MP-1 which inhibits Hippo kinase MST1/2 to activate YAP. Results: We found that YAP was significantly upregulated and activated in the astrocytes of optic nerve in EAE mice. Conditional knockout of YAP in astrocytes caused more severe inflammatory infiltration and demyelination in optic nerve, and damage of retinal ganglion cells (RGCs) in EAE mice. Moreover, YAP deletion in astrocytes promoted the activation of astrocytes and microglia, but inhibited the proliferation of astrocytes of optic nerve in EAE mice. Mechanically, TGF-ß signaling pathway was significantly down-regulated after YAP deletion in astrocytes. Additionally, both qPCR and immunofluorescence assays confirmed the reduction of TGF-ß signaling pathway in YAPGFAP-CKO EAE mice. Interestingly, SRI-011381 partially rescued the deficits in optic nerve and retina of YAPGFAP-CKO EAE mice. Finally, activation of YAP signaling by XMU-MP-1 relieved the neuroinflammation and demyelination in optic nerve of EAE mice. Conclusions: These results suggest astrocytic YAP may prevent the neuroinflammatory infiltration and demyelination through upregulation of TGF-ß signaling and provide targets for the development of therapeutic strategies tailored for MS-ON.
Assuntos
Astrócitos/metabolismo , Encefalomielite Autoimune Experimental/fisiopatologia , Proteínas de Sinalização YAP/metabolismo , Animais , Modelos Animais de Doenças , Encefalomielite Autoimune Experimental/metabolismo , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Esclerose Múltipla/metabolismo , Doenças Neuroinflamatórias , Nervo Óptico/fisiologia , Neurite Óptica/metabolismo , Neurite Óptica/fisiopatologia , Retina/metabolismo , Retina/fisiologia , Células Ganglionares da Retina/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador beta/metabolismo , Fator de Crescimento Transformador beta/fisiologia , Proteínas de Sinalização YAP/fisiologiaRESUMO
Pediococcus acidilactici is commonly used for pediocin production and lactic acid fermentation. However, a high-efficiency genome editing tool is unavailable for this species. In this study, we constructed endogenous subtype II-A CRISPR-Cas system-based genome interference plasmids which carried a "repeat-spacer-repeat" cassette in the pMG36e shuttle vector. These plasmids exhibited self-interference activities in P. acidilactici LA412. Then, the genome-editing plasmids were constructed by cloning the upstream/downstream donor DNA into the corresponding interference plasmids to exert high-efficiency markerless gene deletion, gene integration, and point mutation in P. acidilactici LA412. We found that endogenous CRISPR-mediated depletion of the native plasmids enhanced the cell growth and that integration of an l-lactate dehydrogenase gene into the chromosome enhanced both cell growth and lactic acid production. IMPORTANCE A rapid and precise genome editing tool will promote the practical application of Pediococcus acidilactici, one type of lactic acid bacterium with excellent stress tolerance and probiotic characteristics. This study established a high-efficiency endogenous CRISPR-Cas system-based genome editing tool for P. acidilactici and achieved different genetic manipulations, including gene deletion, gene insertion, mononucleotide mutation, and endogenous plasmid depletion. The engineered strain edited by this tool showed significant advantages in cell growth and lactic acid fermentation. Therefore, our tool can satisfy the requirements for genetic manipulations of P. acidilactici, thus making it a sophisticated chassis species for synthetic biology and bioindustry.
Assuntos
Sistemas CRISPR-Cas , Edição de Genes , Ácido Láctico/metabolismo , Pediococcus acidilactici , Proteínas de Bactérias/genética , Fermentação , L-Lactato Desidrogenase/genética , Engenharia Metabólica , Pediococcus acidilactici/genética , Pediococcus acidilactici/crescimento & desenvolvimento , Pediococcus acidilactici/metabolismo , Mutação PuntualRESUMO
Axonal degeneration is a common pathological feature in many acute and chronic neurological diseases such as spinal cord injury (SCI). SARM1 (sterile alpha and TIR motif-containing 1), the fifth TLR (Toll-like receptor) adaptor, has diverse functions in the immune and nervous systems, and recently has been identified as a key mediator of Wallerian degeneration (WD). However, the detailed functions of SARM1 after SCI still remain unclear. Methods: Modified Allen's method was used to establish a contusion model of SCI in mice. Furthermore, to address the function of SARM1 after SCI, conditional knockout (CKO) mice in the central nervous system (CNS), SARM1Nestin-CKO mice, and SARM1GFAP-CKO mice were successfully generated by Nestin-Cre and GFAP-Cre transgenic mice crossed with SARM1flox/flox mice, respectively. Immunostaining, Hematoxylin-Eosin (HE) staining, Nissl staining and behavioral test assays such as footprint and Basso Mouse Scale (BMS) scoring were used to examine the roles of SARM1 pathway in SCI based on these conditional knockout mice. Drugs such as FK866, an inhibitor of SARM1, and apoptozole, an inhibitor of heat shock protein 70 (HSP70), were used to further explore the molecular mechanism of SARM1 in neural regeneration after SCI. Results: We found that SARM1 was upregulated in neurons and astrocytes at early stage after SCI. SARM1Nestin-CKO and SARM1GFAP-CKO mice displayed normal development of the spinal cords and motor function. Interestingly, conditional deletion of SARM1 in neurons and astrocytes promoted the functional recovery of behavior performance after SCI. Mechanistically, conditional deletion of SARM1 in neurons and astrocytes promoted neuronal regeneration at intermediate phase after SCI, and reduced neuroinflammation at SCI early phase through downregulation of NF-κB signaling after SCI, which may be due to upregulation of HSP70. Finally, FK866, an inhibitor of SARM1, reduced the neuroinflammation and promoted the neuronal regeneration after SCI. Conclusion: Our results indicate that SARM1-mediated prodegenerative pathway and neuroinflammation promotes the pathological progress of SCI and anti-SARM1 therapeutics are viable and promising approaches for preserving neuronal function after SCI.
Assuntos
Proteínas do Domínio Armadillo/metabolismo , Proteínas do Citoesqueleto/metabolismo , Inflamação/metabolismo , NF-kappa B/metabolismo , Regeneração Nervosa/fisiologia , Neurônios/metabolismo , Transdução de Sinais/fisiologia , Traumatismos da Medula Espinal/metabolismo , Animais , Astrócitos/metabolismo , Axônios/metabolismo , Regulação para Baixo/fisiologia , Masculino , Camundongos , Camundongos Knockout , Recuperação de Função Fisiológica/fisiologia , Medula Espinal/metabolismo , Regulação para Cima/fisiologiaRESUMO
Glioma is currently the most widespread and malignant primary intracranial tumor, which is characterized by high heterogeneity and high fatality rates. ß-elemene, which is a bioactive compound extracted from a Chinese herb, Curcuma wenyujin, has been reported to reduce resistance of chemotherapeutic drugs and induce apoptosis in tumor cells. However, the role and mechanisms of ß-elemene in glioma senescence remains unknown. In the present study, we found that a low concentration of ß-elemene (10 µg/mL) induced senescence in glioma cells, including reduction of cell proliferation, hypertrophic morphology, increase of senescence-associated ß-galactosidase (SA-ß-Gal) activity, upregulation of several senescence-associated genes such as p16, p53 and NF-κB, and downregulation of Lamin B1. However, a high concentration of ß-elemene induced apoptosis in glioma cells. Treatment with ß-elemene caused a marked down-regulation of Yes-associated protein (YAP) expression in glioma cells, which is a key transcriptional co-activator in multiple cancers. Moreover, cyclin dependent kinase 6 (CDK6), which is a known downstream target of YAP, was decreased in glioma cells that treated with ß-elemene. The overexpression of YAP and CDK6 significantly rescued ß-elemene-induced senescence in glioma cells. Finally, ß-elemene treatment also induced the senescence of glioma cells in glioma xenograft model through inactivation of YAP-CDK6 pathways, which might inhibit the glioma growth. Taken together, these results reveal a previously unknown role of ß-elemene in glioma cell senescence in vitro and in vivo that is associated with YAP-CDK6 signaling pathway, which will enhance our understanding of glioma cell senescence, and provide novel strategies for the treatment of gliomas.
RESUMO
Patatin, the major protein found in potatoes, was purified and shows several isoforms. The essential amino acid content of patatin was ashighas 76%, indicating that it is a valuable protein source. Patatin was an O-linked glycoprotein that contained fucose monosaccharides, as well as mannose, rhamnose, glucose, galactose, xylose, and arabinose. Patatin had a fucosylated glycan structural feature, which strongly bound AAL (Aleuria aurantia Leukoagglutinin), a known fucose binding lectin. Moreover, thelipid metabolism regulatory effects of patatin on the fat catabolism, fat absorption, and inhibition of lipase activity were measured after high-fat feeding of zebrafish larvae. Results revealed that 37.0 µg/mL patatin promoted 23% lipid decomposition metabolism. Meanwhile patatin could inhibite lipase activity and fat absorption, whose effects accounted for half that of a positive control drug. Our findings suggest that patatin, a fucosylated glycoprotein, could potentially be used as a naturalactiveconstituent with anti-obesity effects.
Assuntos
Metabolismo dos Lipídeos/efeitos dos fármacos , Proteínas de Plantas/química , Proteínas de Plantas/farmacologia , Animais , Larva/efeitos dos fármacos , Larva/metabolismo , Peixe-ZebraRESUMO
Treatment of glioblastoma using radiotherapy and chemotherapy has various outcomes, key among them being cellular senescence. However, the molecular mechanisms of this process remain unclear. In the present study, we tested the ability of D-galactose (D-gal), a reducing sugar, to induce senescence in glioblastoma cells. Following pretreatment with D-gal, glioblastoma cell lines (C6 and U87MG) showed typical characteristics of senescence. These included the reduced cell proliferation, hypertrophic morphology, increased senescence-associated ß-galactosidase activity, downregulation of Lamin B1, and upregulation of several senescence-associated genes such as p16, p53, and NF-κB. Furthermore, our results showed that D-gal was more suitable than etoposide (a DNA-damage drug) in inducing senescence of glioblastoma cells. Mechanistically, D-gal inactivated the YAP-CDK6 signaling pathway, while overexpression of YAP or CDK6 could restore D-gal-induced senescence of C6 cells. Finally, metformin, an anti-aging agent, activated the YAP-CDK6 pathway and suppressed D-gal-induced senescence of C6 cells. Taken together, these findings established a new model for analyzing senescence in glioblastoma cells, which occurred through the YAP-CDK6 pathway. This is expected to provide a basis for development of novel therapies for the treatment of glioblastoma.
RESUMO
Yes-associated protein (YAP) transcriptional coactivator is negatively regulated by the Hippo pathway and functions in controlling the size of multiple organs, such as liver during development. However, it is not clear whether YAP signaling participates in the process of the formation of glia scars after spinal cord injury (SCI). In this study, we found that YAP was upregulated and activated in astrocytes of C57BL/6 male mice after SCI in a Hippo pathway-dependent manner. Conditional knockout (KO) of yap in astrocytes significantly inhibited astrocytic proliferation, impaired the formation of glial scars, inhibited the axonal regeneration, and impaired the behavioral recovery of C57BL/6 male mice after SCI. Mechanistically, the bFGF was upregulated after SCI and induced the activation of YAP through RhoA pathways, thereby promoting the formation of glial scars. Additionally, YAP promoted bFGF-induced proliferation by negatively controlling nuclear distribution of p27Kip1 mediated by CRM1. Finally, bFGF or XMU-MP-1 (an inhibitor of Hippo kinase MST1/2 to activate YAP) injection indeed activated YAP signaling and promoted the formation of glial scars and the functional recovery of mice after SCI. These findings suggest that YAP promotes the formation of glial scars and neural regeneration of mice after SCI, and that the bFGF-RhoA-YAP-p27Kip1 pathway positively regulates astrocytic proliferation after SCI.SIGNIFICANCE STATEMENT Glial scars play critical roles in neuronal regeneration of CNS injury diseases, such as spinal cord injury (SCI). Here, we provide evidence for the function of Yes-associated protein (YAP) in the formation of glial scars after SCI through regulation of astrocyte proliferation. As a downstream of bFGF (which is upregulated after SCI), YAP promotes the proliferation of astrocytes through negatively controlling nuclear distribution of p27Kip1 mediated by CRM1. Activation of YAP by bFGF or XMU-MP-1 injection promotes the formation of glial scar and the functional recovery of mice after SCI. These results suggest that the bFGF-RhoA-YAP-p27Kip1 axis for the formation of glial scars may be a potential therapeutic strategy for SCI patients.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Astrócitos/metabolismo , Proteínas de Ciclo Celular/metabolismo , Gliose/metabolismo , Regeneração Nervosa/fisiologia , Traumatismos da Medula Espinal/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Proteínas de Ciclo Celular/genética , Proliferação de Células/fisiologia , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Gliose/genética , Gliose/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurônios/metabolismo , Recuperação de Função Fisiológica/fisiologia , Transdução de Sinais/fisiologia , Traumatismos da Medula Espinal/genética , Traumatismos da Medula Espinal/patologia , Proteínas de Sinalização YAPRESUMO
Olfactory ensheathing cells (OECs) are unique glial cells with axonal growth-promoting properties in the olfactory epithelium and olfactory bulb, covering the entire length of the olfactory nerve. The proliferation of OECs is necessary for the formation of the presumptive olfactory nerve layer (ONL) during development and OECs transplantation. However, the molecular mechanism underlying the regulation of OEC proliferation in the ONL still remains unknown. In the present study, we examined the role of sphingosine 1-phosphate (S1P) and S1P receptors (S1PRs) on OEC proliferation. Initially, reverse transcription-PCR (RT-PCR), western blot and immunostaining revealed that S1PRs were highly expressed in the OECs in vitro and in vivo. Furthermore, we found that S1P treatment promoted the proliferation of primary cultured OECs mediated by S1PR1. Mechanistically, yes-associated protein (YAP) was required for S1P-induced OEC proliferation through RhoA signaling. Finally, conditional knockout of YAP in OECs reduced OEC proliferation in ONL, which impaired the axonal projection and growth of olfactory sensory neurons, and olfactory functions. Taken together, these results reveal a previously unrecognized function of S1P/RhoA/YAP pathway in the proliferation of OECs, contributing to the formation of ONL and the projection, growth, and function of olfactory sensory neurons during development.
Assuntos
Neuroglia , Nervo Olfatório , Proliferação de Células , Células Cultivadas , Lisofosfolipídeos , Bulbo Olfatório , Esfingosina/análogos & derivadosRESUMO
Rotavirus (RV) is a major foodborne pathogen. For RV prevention and control, it is a key to uncover the interaction mechanism between virus and its receptors. However, it is hard to specially purify the viral receptors, including histo-blood group antigens (HBGAs). Previously, the protruding domain protein (P protein) of human norovirus (genotype II.4) was displayed on the surface of Escherichia coli, and it specifically recognized and captured the viral ligands. In order to further verify the feasibility of the system, P protein was replaced by VP8* of RV (G9P[8]) in this study. In the system, VP8* could be correctly released by thrombin treatment with antigenicity retaining, which was confirmed by Western blot and Enzyme-Linked Immunosorbent Assays. Type A HBGAs from porcine gastric mucin (PGM) were recognized and captured by this system. From saliva mixture, the captured viral receptor bound with displayed VP8* was confirmed positive with monoclonal antibody against type A HBGAs. It indicated that the target ligands could be easily separated from the complex matrix. These results demonstrate that the bacterial surface display system will be an effective platform to explore viral receptors/ligands from cell lines or food matrix.
Assuntos
Técnicas de Visualização da Superfície Celular/métodos , Receptores Virais/genética , Rotavirus/genética , Animais , Escherichia coli , Genótipo , Humanos , Ligação Proteica , Proteínas de Ligação a RNA/genética , Infecções por Rotavirus/virologia , Saliva/virologia , Suínos , Proteínas não Estruturais Virais/genéticaRESUMO
OBJECTIVE: We aimed to investigate the roles and underlying mechanisms of YAP in the proliferation of neuroblastoma cells. METHODS: The expression level of YAP was evaluated by Western blotting and immunocytochemistry. Cell viability, cell proliferation and growth were detected by CCK-8, PH3 and Ki67 immunostaining, and the real-time cell analyser system. The nuclear and cytoplasmic proteins of p27Kip1 were dissociated by the nuclear-cytosol extraction kit and were detected by Western blotting and immunocytochemistry. mRNA levels of Akt, CDK5 and CRM1 were determined by qRT-PCR. RESULTS: YAP was enriched in SH-SY5Y cells (a human neuroblastoma cell line). Knock-down of YAP in SH-SY5Y cells or SK-N-SH cell line (another human neuroblastoma cell line) significantly decreased cell viability, inhibited cell proliferation and growth. Mechanistically, knock-down of YAP increased the nuclear location of p27Kip1 , whereas serum-induced YAP activation decreased the nuclear location of p27Kip1 and was required for cell proliferation. Meanwhile, overexpression of YAP in these serum-starved SH-SY5Y cells decreased the nuclear location of p27Kip1 , promoted cell proliferation and overexpression of p27Kip1 in YAP-activated cells inhibited cell proliferation. Furthermore, knock-down of YAP reduced Akt mRNA and protein levels. Overexpression of Akt in YAP-downregulated cells decreased the nuclear location of p27Kip1 and accelerated the proliferation of SH-SY5Y cells. CONCLUSIONS: Our studies suggest that YAP promotes the proliferation of neuroblastoma cells through negatively controlling the nuclear location of p27Kip1 mediated by Akt.