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1.
BMC Biotechnol ; 24(1): 2, 2024 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-38200466

RESUMO

BACKGROUND: Lytic polysaccharide monooxygenases (LPMOs) catalyzing the oxidative cleavage of different types of polysaccharides have potential to be used in various industries. However, AA13 family LPMOs which specifically catalyze starch substrates have relatively less members than AA9 and AA10 families to limit their application range. Amylase has been used in enzymatic desizing treatment of cotton fabric for semicentury which urgently need for new assistant enzymes to improve reaction efficiency and reduce cost so as to promote their application in the textile industry. RESULTS: A total of 380 unannotated new genes which probably encode AA13 family LPMOs were discovered by the Hidden Markov model scanning in this study. Ten of them have been successfully heterologous overexpressed. AlLPMO13 with the highest activity has been purified and determined its optimum pH and temperature as pH 5.0 and 50 °C. It also showed various oxidative activities on different substrates (modified corn starch > amylose > amylopectin > corn starch). The results of enzymatic textile desizing application showed that the best combination of amylase (5 g/L), AlLPMO13 (5 mg/L), and H2O2 (3 g/L) made the desizing level and the capillary effects increased by 3 grades and more than 20%, respectively, compared with the results treated by only amylase. CONCLUSION: The Hidden Markov model constructed basing on 34 AA13 family LPMOs was proved to be a valid bioinformatics tool for discovering novel starch-active LPMOs. The novel enzyme AlLPMO13 has strong development potential in the enzymatic textile industry both concerning on economy and on application effect.


Assuntos
Peróxido de Hidrogênio , Amido , Humanos , Polissacarídeos , Amilases , Biologia Computacional , Oxigenases de Função Mista/genética , Têxteis
2.
J Transl Med ; 22(1): 459, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38750573

RESUMO

Mesenchymal stem/stromal cells (MSCs) represent a heterogeneous cell population distributed throughout various tissues, demonstrating remarkable adaptability to microenvironmental cues and holding immense promise for disease treatment. However, the inherent diversity within MSCs often leads to variability in therapeutic outcomes, posing challenges for clinical applications. To address this heterogeneity, purification of MSC subpopulations through marker-based isolation has emerged as a promising approach to ensure consistent therapeutic efficacy. In this review, we discussed the reported markers of MSCs, encompassing those developed through candidate marker strategies and high-throughput approaches, with the aim of explore viable strategies for addressing the heterogeneity of MSCs and illuminate prospective research directions in this field.


Assuntos
Biomarcadores , Células-Tronco Mesenquimais , Humanos , Células-Tronco Mesenquimais/citologia , Biomarcadores/metabolismo , Animais , Separação Celular/métodos
3.
Small ; 18(8): e2104202, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34877766

RESUMO

Colloidal lithography provides a rapid and low-cost approach to construct 2D periodic surface nanostructures. However, an impressive demonstration to prepare large-area colloidal template is still missing. Here, a high-efficient and flexible technique is proposed to fabricate self-assembly monolayers consisting of orderly-packed polystyrene spheres at air/water interface via ultrasonic spray. This "non-contact" technique exhibits great advantages in terms of scalability and adaptability due to its renitent interface dynamic balance. More importantly, this technique is not only competent for self-assembly of single-sized polystyrene spheres, but also for binary polystyrene spheres, completely reversing the current hard situation of preparing large-area self-assembly monolayers. As a representative application, hexagonal-packed silver-coated silicon nanorods array (Si-NRs@Ag) is developed as an ultrasensitive surface-enhanced Raman scattering (SERS) substrate with very low limit-of-detection for selective detection of explosive 2,4,6-trinitrotoluene down to femtomolar (10-14 m) range. The periodicity and orderliness of the array allow hot spots to be designed and constructed in a homogeneous fashion, resulting in an incomparable uniformity and reproducibility of Raman signals. All these excellent properties come from the Si-NRs@Ag substrate based on the ordered structure, open surface, and wide-range electric field, providing a robust, consistent, and tunable platform for molecule trapping and SERS sensing for a wide range of organic molecules.


Assuntos
Nanosferas , Nanoestruturas , Nanoestruturas/química , Reprodutibilidade dos Testes , Prata/química , Análise Espectral Raman/métodos
4.
J Am Soc Nephrol ; 31(1): 54-65, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31604808

RESUMO

BACKGROUND: Although mesenchymal stem cells (MSCs) might offer a promising strategy for treating SLE, their immunoregulatory plasticity makes their therapeutic effects unpredictable. Whether overexpressing IL-37, an IL-1 family member with immunosuppressive activity, might enhance the therapeutic effects of these cells for SLE is unknown. METHODS: We genetically modified MSCs to overexpress IL-37 and assessed their effects on immune suppression in vitro. We also evaluated the effects of such cells versus effects of various controls after transplanting them into MRL/lpr mice (model of SLE). RESULTS: Stem cell characteristics did not appear altered in MSCs overexpressing IL-37. These cells had enhanced immunosuppression in vitro in terms of inhibiting splenocyte proliferation, reducing proinflammatory factors (IL-1ß, TNF-α, IL-17, and IL-6), and suppressing autoantibodies (anti-dsDNA and anti-ANA). Compared with animals receiving control MSCs or IL-37 treatment alone, MRL/lpr mice transplanted with IL-37-overexpressing cells displayed improved survival and reduced signs of SLE (indicated by urine protein levels, spleen weight, and renal pathologic scores); they also had significantly lower expression of proinflammatory factors, lower total antibody levels in serum and urine, lower autoantibody production, and showed reduced T cell numbers in the serum and kidney. Expression of IL-37 by MSCs can maintain higher serum levels of IL-37, and MSCs had prolonged survival after transplantation, perhaps through IL-37 suppressing the inflammatory microenvironment. CONCLUSIONS: Mutually reinforcing interaction between MSCs and IL-37 appears to underlie their additive therapeutic effects. Genetic modification to overexpress IL-37 might offer a way to enhance the stability and effectiveness of MSCs in treating SLE.


Assuntos
Interleucina-1/biossíntese , Interleucina-1/uso terapêutico , Lúpus Eritematoso Sistêmico/terapia , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/metabolismo , Animais , Células Cultivadas , Terapia Combinada , Feminino , Camundongos , Camundongos Endogâmicos MRL lpr
5.
Microb Cell Fact ; 19(1): 25, 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32028973

RESUMO

BACKGROUND: pWB980 derived from pUB110 is a promising expression vector in Bacillus for its high copy number and high stability. However, the low transformation rate of recombinant plasmids to the wild cells limited the application of it. On the basis of pWB980, constructing an E. coli-B. subtilis shuttle plasmid could facilitate the transformation rate to Bacillus cells. Because the insertion site for E. coli replication origin sequence (ori) is not unique in pWB980, in order to investigate the best insertion site, eight shuttle plasmids (pUC980-1 ~ pUC980-8) containing all possible insertion sites and directions were constructed. RESULTS: The results showed that all the selected insertion sites could be used to construct shuttle plasmid but some sites required a specific direction. And different insertion sites led to different properties of the shuttle plasmids. The best shuttle plasmids pUC980-1 and pUC980-2, which showed copies more than 450 per cell and segregational stabilities up to 98%, were selected for heterologous expressions of an alkaline pectate lyase gene pelN, an alkaline protease spro1 and a pullulanase gene pulA11, respectively. The highest extracellular activities of PelN, Spro1 and PulA11 were up to 5200 U/mL, 21,537 U/mL and 504 U/mL correspondingly after 54 h, 60 h and 48 h fermentation in a 10 L fermentor. Notably, PelN and Spro1 showed remarkably higher yields in Bacillus than previous reports. CONCLUSION: The optimum ori insertion site was the upstream region of BA3-1 in pWB980 which resulted in shuttle plasmids with higher copy numbers and higher stabilities. The novel shuttle plasmids pUC980-1 and pUC980-2 will be promising expression vectors in B. subtilis. Moreover, the ori insertion mechanism revealed in this work could provide theoretical guidance for further studies of pWB980 and constructions of other shuttle plasmids.


Assuntos
Bacillus subtilis/genética , Escherichia coli/genética , Vetores Genéticos/genética , Plasmídeos/genética , Variações do Número de Cópias de DNA , Instabilidade Genômica/genética
6.
Int J Mol Sci ; 21(16)2020 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-32796599

RESUMO

Steviol glycosides (SGs) with zero calories and high-intensity sweetness are the best substitutes of sugar for the human diet. Uridine diphosphate dependent glycosyltransferase (UGT) UGT76G1, as a key enzyme for the biosynthesis of SGs with a low heterologous expression level, hinders its application. In this study, a suitable fusion partner, Smt3, was found to enhance the soluble expression of UGT76G1 by 60%. Additionally, a novel strategy to improve the expression of Smt3-UGT76G1 was performed, which co-expressed endogenous genes prpD and malK in Escherichia coli. Notably, this is the first report of constructing an efficient E. coli expression system by regulating prpD and malK expression, which remarkably improved the expression of Smt3-UGT76G1 by 200% as a consequence. Using the high-expression strain E. coli BL21 (DE3) M/P-3-S32U produced 1.97 g/L of Smt3-UGT76G1 with a yield rate of 61.6 mg/L/h by fed-batch fermentation in a 10 L fermenter. The final yield of rebadioside A (Reb A) and rebadioside M (Reb M) reached 4.8 g/L and 1.8 g/L, respectively, when catalyzed by Smt3-UGT76G1 in the practical UDP-glucose regeneration transformation system in vitro. This study not only carried out low-cost biotransformation of SGs but also provided a novel strategy for improving expression of heterologous proteins in E. coli.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Glicosídeos/biossíntese , Glicosiltransferases/metabolismo , Hidroliases/metabolismo , Biocatálise , Reatores Biológicos/microbiologia , Biotransformação , Fermentação , Glicosídeos/química , Glicosilação , Plasmídeos/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Recombinação Genética/genética , Solubilidade
7.
Appl Microbiol Biotechnol ; 103(3): 1441-1453, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30498978

RESUMO

A novel method involving ethanol-induced increase in the heterologous recombinant protein expression in E. coli cells was commonly used in recent studies. However, the detailed mechanism of this method is still to be revealed. This work used comparative transcriptomic analysis and numerous experiments to uncover the mechanism of ethanol effects on the expression of heterologous catalase in the recombinant strain E. coli BL21 (pET26b-katA). The key regulatory genes malK and prpD were found to have the most significant effects on the expression of heterologous catalase. Thus, the maltose ABC transporter and carbon metabolism from propanoate metabolism to citrate cycle were found to be the main regulatory pathways activated by ethanol to enhance the synthesis of heterologous proteins. Based on these mechanisms, a universally applicable E. coli expression host strain for improving the expression of heterologous proteins might be constructed.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Catalase/biossíntese , Proteínas de Escherichia coli/metabolismo , Escherichia coli/efeitos dos fármacos , Hidroliases/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética , Reatores Biológicos/microbiologia , Catalase/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Perfilação da Expressão Gênica , Hidroliases/genética , Estresse Oxidativo/fisiologia , Proteínas Recombinantes/biossíntese
8.
Cell Physiol Biochem ; 48(1): 131-137, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30001549

RESUMO

BACKGROUND/AIMS: The target genome editing technology not only plays an important role in basic biology studies but also holds a great promise for potential clinical applications. The new generation of engineered nuclease RGEN (RNA Guided EndoNuclease) is much easier to construct and modify, and attracts more attentions. In the current study, we compared different plasmid construction strategies of Cas9-gRNA (guide RNA). METHODS: Different plasmid construction strategies of Cas9-gRNA were compared. And more modifications were introduced into the plasmid construction strategy. RESULTS: The plasmid construction efficiency of expressing the gRNA and Cas9 in one plasmid was lower than expressing them in two separate plasmids. However, they showed the similar genome editing efficiency. We further introduced the Golden-gate assembly and blue-white screening approaches into the Cas9-gRNA construction procedures, without the process of vector digestion and gel purification. CONCLUSIONS: Combing with the optimized gRNA structure (gRNA-BL) we identified before, we established one more cost-effective, time-saving and efficient plasmid construction strategy for Cas9-gRNA.


Assuntos
Sistemas CRISPR-Cas/genética , Plasmídeos/metabolismo , RNA Guia de Cinetoplastídeos/metabolismo , Genes Reporter , Células HEK293 , Humanos , Plasmídeos/genética , RNA Guia de Cinetoplastídeos/genética
9.
J Ind Microbiol Biotechnol ; 45(6): 417-428, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29737437

RESUMO

Bacillus sp. strains as attractive hosts for the production of heterologous secretory proteins usually play important roles in bio-industry. However, low transformation efficiency of exogenous plasmids limited the application of Bacillus species. Here, a novel plasmid interspecific transfer system, with high transformation efficiency, high positive rate, and convenient manipulation, has been successfully constructed. A high electrotransformation efficiency strain Bacillus subtilis F-168 containing the counter-selectable marker mazF was used as the plasmid donor strain in this transfer method. A shuttled plasmid pBE980 and its recombinant plasmids pBE980::pulA and pBE980::HSPA were successfully transferred into the recipient Bacillus strains (Bacillus amyloliquefaciens 66, Bacillus licheniformis 124 and Bacillus megaterium 258) by this method. After co-culturing the donor cells (OD600nm = 1.3-1.7) and the recipient cells (OD600nm = 0.5-0.9) for 24 h in 22 °C, more than 1.0 × 105 positive transformants were obtained and a interspecific transformation efficiency of 1.0 × 10-3. It would provide a new approach for genetic manipulation in Bacillus strains and accelerate the research progress of the wild Bacillus strains in bio-industry.


Assuntos
Bacillus megaterium/genética , Bacillus subtilis/genética , Proteínas de Bactérias/genética , Endorribonucleases/genética , Plasmídeos/genética , Recombinação Genética , Proteínas de Bactérias/metabolismo , Técnicas de Cocultura , Marcadores Genéticos , Microbiologia Industrial , Temperatura
10.
Adv Exp Med Biol ; 1089: 73-85, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29767288

RESUMO

Mesenchymal stem cells (MSCs) have been intensively studied and applied in regenerative medicine and tissue engineering. Recently, their immune modulation functions make them as attractive potential approaches for autoimmune disease treatment. Systemic lupus erythematosus (SLE) is one type of chronic autoimmune diseases with multi-organ damaged by the immune system. Although current available treatments are effective for some patients, others are refractory for these therapies. The immuno-modulatory and regenerative characteristics of MSCs make them as one promising candidate for treating SLE. Thus, we would discuss their immune modulation effects, pre-clinical and clinical applications, and the potentials for immune tolerance re-establishment in SLE here.


Assuntos
Lúpus Eritematoso Sistêmico/terapia , Transplante de Células-Tronco Mesenquimais , Humanos , Células-Tronco Mesenquimais/citologia
11.
Stem Cells ; 34(11): 2693-2706, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27333945

RESUMO

Recent pre-clinical and clinical studies have suggested that endogenous cardiospheres (eCS) are potentially safe and effective for cardiac regeneration following myocardial infarction (MI). Nevertheless the preparation of autologous eCS requires invasive myocardial biopsy with limited yield. We describe a novel approach to generate induced cardiospheres (iCS) from adult skin fibroblasts via somatic reprogramming. After infection with Sox2, Klf4, and Oct4, iCS were generated from mouse adult skin fibroblasts treated with Gsk3ß inhibitor-(2'Z,3'E)- 6-Bromoindirubin-3'-oxime and Oncostatin M. They resembled eCS, but contained a higher percentage of cells expressing Mesp1, Isl1, and Nkx2.5. They were differentiated into functional cardiomyocytes in vitro with similar electrophysiological properties, calcium transient and contractile function to eCS and mouse embryonic stem cell-derived cardiomyocytes. Transplantation of iCS (1 × 106 cells) into mouse myocardium following MI had similar effects to transplantation of eCS but significantly better than saline or fibroblast in improving left ventricular ejection fraction, increasing anterior/septal ventricular wall thickness and capillary density in the infarcted region 4 weeks after transplantation. No tumor formation was observed. iCS generated from adult skin fibroblasts by somatic reprogramming and a cocktail of Gsk3ß inhibitor-6-Bromoindirubin-3'-oxime and Oncostatin M may represent a novel source for cell therapy in MI. Stem Cells 2016;34:2693-2706.


Assuntos
Reprogramação Celular , Fibroblastos/metabolismo , Infarto do Miocárdio/terapia , Miócitos Cardíacos/transplante , Regeneração/fisiologia , Esferoides Celulares/transplante , Potenciais de Ação , Animais , Cálcio/metabolismo , Diferenciação Celular , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Expressão Gênica , Glicogênio Sintase Quinase 3 beta/antagonistas & inibidores , Glicogênio Sintase Quinase 3 beta/genética , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Indóis/farmacologia , Fator 4 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Camundongos , Infarto do Miocárdio/genética , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Fator 3 de Transcrição de Octâmero/genética , Fator 3 de Transcrição de Octâmero/metabolismo , Oncostatina M/farmacologia , Oximas/farmacologia , Cultura Primária de Células , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição SOXB1/metabolismo , Pele/citologia , Pele/efeitos dos fármacos , Pele/metabolismo , Esferoides Celulares/citologia , Esferoides Celulares/metabolismo , Transdução Genética , Função Ventricular Esquerda/fisiologia
12.
BMC Nephrol ; 18(1): 65, 2017 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-28201997

RESUMO

BACKGROUND: Interleukin-19 (IL-19) is a newly discovered cytokine belonging to the Interleukin-10(IL-10) family. IL-19 have indispensable functions in many inflammatory processes and also can induce the angiogenic potential of endothelial cells. The purpose of present study was to investigate the relation of serum interleukin-19 (IL-19) levels with diabetic nephropathy (DN). METHODS: Two hundred study groups of patients with type 2 diabetes mellitus (T2DM) (109 males and 91 females) were recruited, included normoalbuminuria(n = 102), microalbuminuria(n = 72) and macroalbuminuria(n = 26) . The 50 healthy blood donors were enrolled for the control group. All subjects were assessed for: IL-19, High-sensitivity C-reactive protein (Hs-CRP), Cystatin C, urinary albumin excretion rate (UAE) and glycosylated hemoglobin A1c(HbA1c). RESULTS: The serum IL-19 levels in DN patients were found to be significantly higher compared to controls. IL-19 levels were significantly positively correlated with Hs-CRP, Cystatin C, UAE and HbA1c(r = 0.623, 0.611,0.591 and 0.526 respectively, P < 0.01). Multivariable logistic regression analysis showed IL-19 levels (P = 0.01) were found to be independently associated with patients with DN. CONCLUSIONS: IL-19 is significantly positive correlated with UAE and Cystatin C. IL-19 may play an important role that contributes to the progression of diabetic nephropathy.


Assuntos
Nefropatias Diabéticas/sangue , Nefropatias Diabéticas/diagnóstico , Interleucinas/sangue , Biomarcadores/sangue , China/epidemiologia , Nefropatias Diabéticas/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Reprodutibilidade dos Testes , Fatores de Risco , Sensibilidade e Especificidade
13.
J Ind Microbiol Biotechnol ; 43(7): 977-87, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27130461

RESUMO

To improve the extracellular production of alkaline ß-mannanase from alkaliphilic Bacillus sp. N16-5 in Escherichia coli, two truncated recombinant mannanases (32a-ManAR2 and 22b-ManAR2) were obtained. Compared with the full-length mannanases (32a-ManAR1 and 22b-ManAR1), the truncated mannanases not only showed higher secretion rate, but also exhibited higher thermostability and alkalistability. The K m value (11 mg/mL) of 32a-ManAR2 was higher than that (1.46 mg/mL) of 32a-ManAR1. The specific activity of 22b-ManAR2 was 2.7 times higher than that of 22b-ManAR1. 22b-ManAR2 showed the highest k cat/K m value of 602.7 ml/mg s. The parameters of induction for recombinant mannanase production of E. coli BL21 (pET32a-manAR2) and E. coli BL21 (pET22b-manAR2) were subsequently optimized. The yield of soluble mannanase was found to be enhanced with lower induction temperature (25 °C), lower IPTG concentration (0.01-0.05 mM), and Triton X-100 supplement (0.1 %) in a shake flask. Moreover, a one-time feeding strategy and Triton X-100 supplement were applied in production of 22b-ManAR2 in a 10 L fermentor. The productivity of the total soluble mannanase reached 9284.64 U/mL with the extracellular rate of 74 % at 46 h of fermentation, which was the highest productive level of alkaline ß-mannanase in recombinant E. coli to date.


Assuntos
Bacillus/enzimologia , Escherichia coli/metabolismo , Fermentação , beta-Manosidase/metabolismo , Reatores Biológicos , Temperatura Baixa , Meios de Cultura/química , Microbiologia Industrial , Octoxinol/química , Proteínas Recombinantes/metabolismo
14.
Proteins ; 82(9): 1685-93, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24375572

RESUMO

Pullulanase is a debranching enzyme that specifically hydrolyzes the α-1,6 glycosidic linkage of α-glucans, and has wide industrial applications. Here, we report structural and functional studies of a new thermostable pullulanase from Anoxybacillus sp. LM18-11 (PulA). Based on the hydrolysis products, PulA was classified as a type I pullulanase. It showed maximum activity at 60°C and pH 6.0. Kinetic study showed that the specific activity and Km for pullulan of PulA are 750 U mg(-1) and 16.4 µmol L(-1), respectively. PulA has a half-life of 48 h at 60°C. The remarkable thermostability makes PulA valuable for industrial usage. To further investigate the mechanism of the enzyme, we solved the crystal structures of PulA and its complexes with maltotriose and maltotetraose at 1.75-2.22 Å resolution. The PulA structure comprises four domains (N1, N2, A, and C). A is the catalytic domain, in which three conserved catalytic residues were identified (D413, E442, and D526). Two molecules of oligosaccharides were seen in the catalytic A domain in a parallel binding mode. Interestingly, another two oligosaccharides molecules were found between the N1 domain and the loop between the third ß-strand and the third α-helix in the A domain. Based on sequence alignment and the ligand binding pattern, the N1 domain is identified as a new type of carbohydrate-binding motif and classified to the CBM68 family. The structure solved here is the first structure of pullulanase which has carbohydrate bound to the N1 domain.


Assuntos
Anoxybacillus/enzimologia , Glucanos/metabolismo , Glicosídeo Hidrolases/farmacocinética , Glicosídeo Hidrolases/ultraestrutura , Sequência de Aminoácidos , Sítios de Ligação/genética , Domínio Catalítico , Cristalografia por Raios X , Modelos Moleculares , Oligossacarídeos/metabolismo , Receptores de Superfície Celular/metabolismo , Alinhamento de Sequência
15.
Lab Chip ; 24(4): 719-727, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38275006

RESUMO

Traditional lead-based primary explosives present challenges in application to micro-energetics-on-a-chip. It is highly desired but still remains challenging to design a primary explosive for the development of powerful yet safe energetic films. Copper-based azides (Cu(N3)2 or CuN3, CA) are expected to be ideal alternatives owing to their properties such as excellent device compatibility, excellent detonation performance, and low environmental pollution. However, the significantly high electrostatic sensitivity of CA limits its use in micro-electro-mechanical systems (MEMS). This study presents an in situ electrochemical approach to preparing and modifying a CA film with excellent electrostatic safety using a Cu chip. Herein, a CA film is prepared by employing Cu nanorod arrays as precursors. Next, polypyrrole (PPy) is directly coated on the surface of the CA materials to produce a CA@PPy composite energetic film using the electrochemical process. The results show that CuN3 is first generated and gradually oxidized to Cu(N3)2, essentially forming enclosed nest-like structures during electrochemical azidation. The microstructure and composition of the product can be regulated by varying the current density and reaction time, which leads to controllable heat output of the CA from 521 to 1948 J g-1. Notably, the composite energetic film exhibits excellent electrostatic sensitivity (2.69 mJ) owing to the excellent conductivity of PPy. Thus, this study offers novel ideas for the further advances of composite energetic materials and applications in MEMS explosive systems.

16.
Stem Cell Res Ther ; 15(1): 92, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38539221

RESUMO

BACKGROUND: Previously, we have demonstrated that the batch variations of human platelet lysate (conventional MSC expansion medium) induce MSC heterogeneity and therapeutic inconsistency. On the other hand, the MSCs expanded with chemical defined medium have improved therapeutic consistency. METHODS: In the current study, we studied the MSC subpopulation composition and variation in different types and batches of MSC expansion medium with scRNA-seq analysis. RESULTS: MSCs expanded with different batches of media have higher levels of heterogeneity from the perspective of cell subpopulation composition at transcriptome levels and therapeutic inconsistency. The CD317+ subpopulation has enhanced immune suppression activities. And the percentage of CD317+ MSCs within MSCs is tightly correlated with its immune suppression activities, and also contributes to the heterogeneity and therapeutic inconsistency of MSCs. the CD317+ MSCs have increased expression levels of PTX3, which might stabilize the TSG6 protein and improve the therapeutic effects CONCLUSIONS: Thus, purifying CD317+ MSCs is one efficient strategy to reduce MSC heterogeneity and increase the therapeutic consistency of MSCs.


Assuntos
Células-Tronco Mesenquimais , Humanos , Células-Tronco Mesenquimais/metabolismo , Transdução de Sinais , Proliferação de Células , Diferenciação Celular
17.
Stem Cell Res Ther ; 15(1): 2, 2024 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-38169422

RESUMO

BACKGROUND: Although both preclinical and clinical studies have shown the great application potential of MSCs (mesenchymal stem/stromal cells) in treating many kinds of diseases, therapeutic inconsistency resulting from cell heterogeneity is the major stumbling block to their clinical applications. Cell population diversity and batch variation in the cell expansion medium are two major inducers of MSC heterogeneity. METHODS: Cell population diversity was investigated through single-cell RNA sequencing analysis of human MSCs derived from the umbilical cord and expanded with fully chemically defined medium in the current study. Then, the MSC subpopulation with enhanced anti-inflammatory effects was studied in vitro and in vivo. RESULTS: Our data showed that MSCs contain different populations with different functions, including subpopulations with enhanced functions of exosome secretion, extracellular matrix modification and responses to stimuli (regeneration and immune response). Among them, CD317+ MSCs have improved differentiation capabilities and enhanced immune suppression activities. Underlying mechanism studies showed that higher levels of TSG6 confer enhanced anti-inflammatory functions of CD317+ MSCs. CONCLUSIONS: Thus, CD317+ MSCs might be a promising candidate for treating immunological disorder-related diseases.


Assuntos
Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Humanos , Diferenciação Celular , Proliferação de Células , Matriz Extracelular , Anti-Inflamatórios/farmacologia
18.
Hum Mol Genet ; 20(16): 3176-87, 2011 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-21593220

RESUMO

Directed hepatocyte differentiation from human induced pluripotent stem cells (iPSCs) potentially provides a unique platform for modeling liver genetic diseases and performing drug-toxicity screening in vitro. Wilson's disease is a genetic disease caused by mutations in the ATP7B gene, whose product is a liver transporter protein responsible for coordinated copper export into bile and blood. Interestingly, the spectrum of ATP7B mutations is vast and can influence clinical presentation (a variable spectrum of hepatic and neural manifestations), though the reason is not well understood. We describe the generation of iPSCs from a Chinese patient with Wilson's disease that bears the R778L Chinese hotspot mutation in the ATP7B gene. These iPSCs were pluripotent and could be readily differentiated into hepatocyte-like cells that displayed abnormal cytoplasmic localization of mutated ATP7B and defective copper transport. Moreover, gene correction using a self-inactivating lentiviral vector that expresses codon optimized-ATP7B or treatment with the chaperone drug curcumin could reverse the functional defect in vitro. Hence, our work describes an attractive model for studying the pathogenesis of Wilson's disease that is valuable for screening compounds or gene therapy approaches aimed to correct the abnormality. In the future, once relevant safety concerns (including the stability of the mature liver-like phenotype) and technical issues for the transplantation procedure are solved, hepatocyte-like cells from similarly genetically corrected iPSCs could be an option for autologous transplantation in Wilson's disease.


Assuntos
Adenosina Trifosfatases/genética , Proteínas de Transporte de Cátions/genética , Curcumina/uso terapêutico , Terapia Genética , Hepatócitos/metabolismo , Degeneração Hepatolenticular/tratamento farmacológico , Degeneração Hepatolenticular/patologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Adenosina Trifosfatases/metabolismo , Adenosina Trifosfatases/uso terapêutico , Sequência de Bases , Proteínas de Transporte de Cátions/metabolismo , Proteínas de Transporte de Cátions/uso terapêutico , Cobre/metabolismo , ATPases Transportadoras de Cobre , Humanos , Masculino , Pessoa de Meia-Idade , Chaperonas Moleculares/uso terapêutico , Dados de Sequência Molecular , Mutação/genética , Transporte Proteico , Frações Subcelulares/metabolismo
19.
Bioengineering (Basel) ; 10(8)2023 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-37627862

RESUMO

At present, the double-enzyme catalyzed method using maltooligosyltrehalose synthase (MTSase) and maltooligosyltrehalose trehalohydrolase (MTHase) is the mainstream technology for industrial trehalose production. However, MTSase and MTHase are prepared mainly using the heterologous expression in the engineered Escherichia coli strains so far. In this study, we first proved that the addition of 3 U/g neutral pullulanase PulA could enhance the trehalose conversion rate by 2.46 times in the double-enzyme catalyzed system. Then, a CBM68 domain was used to successfully assist the secretory expression of MTSase and MTHase from Arthrobacter ramosus S34 in Bacillus subtilis SCK6. At the basis, an engineered strain B. subtilis PSH02 (amyE::pulA/pHT43-C68-ARS/pMC68-ARH), which co-expressed MTSase, MTHase, and PulA, was constructed. After the 24 h fermentation of B. subtilis PSH02, the optimum ratio of the extracellular multi-enzymes was obtained to make the highest trehalose conversion rate of 80% from 100 g/L maltodextrin. The high passage stability and multi-enzyme preservation stability made B. subtilis PSH02 an excellent industrial production strain. Moreover, trehalose production using these extracellular enzymes produced via the one-step fermentation of B. subtilis PSH02 would greatly simplify the procedure for multi-enzyme preparation and be expected to reduce production costs.

20.
J Bacteriol ; 194(22): 6348, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23105079

RESUMO

Alicyclobacillus hesperidum is a thermoacidophilic bacterium. We isolated strain URH17-3-68 from hot spring sludge in Tengchong, Yunnan province, China. Its extracellular products include heat- and acid-stable enzymes which are important for industrial applications. Here we report the draft genome of this strain.


Assuntos
Alicyclobacillus/classificação , Alicyclobacillus/genética , Genoma Bacteriano , Fontes Termais , Dados de Sequência Molecular , Microbiologia do Solo
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