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1.
Int J Biol Macromol ; : 133652, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38971273

RESUMO

Eighteen S rRNA factor 1 (ESF1) is a predominantly nucleolar protein essential for embryogenesis. Our previous studies have suggested that Esf1 is a negative regulator of the tumor suppressor protein p53. However, it remains unclear whether ESF1 contributes to tumorigenesis. In this current research, we find that increased ESF1 expression correlates with poor survival in multiple tumors including pancreatic cancer. ESF1 is able to regulate cell proliferation, migration, DNA damage-induced apoptosis, and tumorigenesis. Mechanistically, ESF1 physically interacts with MDM2 and is essential for maintaining the stability of MDM2 protein by inhibiting its ubiquitination. Additionally, ESF1 also prevented stress-induced stabilization of p53 in multiple cancer cells. Hence, our findings suggest that ESF1 is a potent regulator of the MDM2-p53 pathway and promotes tumor progression.

3.
Front Psychol ; 15: 1372694, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38882513

RESUMO

Background: The interplay between teaching engagement and performance has garnered attention in both theoretical and empirical research, primarily due to its influence on student academic achievement, teacher well-being, and the realization of institutional goals. This is especially pertinent in the realm of preschool education, where the scope of learning extends beyond academic content to encompass the broader socialization of children. Drawing from Affective Neuroscience research, this study investigates the role of affective tendencies as mediators in the relationship between work engagement and job performance. Objective: The primary aim of this research is to examine a chain mediation model that hypothesizes the predictive role of teacher engagement. This model posits the intermediary influence of four basic emotions-CARING, SEEKING, ANGER, and FEAR-followed by the mediating effect of job satisfaction on teacher job performance. Method: The study utilized a sample of 842 Chinese preschool teachers. Data were collected through an online questionnaire, employing a time-lagged design. The analysis was conducted using Model 80 of the PROCESS Macros. Results: The findings reveal that both positive and negative emotions significantly predict teachers' job satisfaction. However, job satisfaction does not influence job performance. The analysis confirmed the direct and total effects of teacher engagement, as well as the indirect effects, particularly through the positive emotion of Caring. Implications: The results are instrumental in informing and refining interventions designed to enhance teacher engagement and performance, underscoring the importance of emotional factors in the educational environment.

5.
Biochim Biophys Acta Mol Basis Dis ; 1870(7): 167276, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38844114

RESUMO

The role of hypoxia in the tumor microenvironment of intrahepatic cholangiocarcinoma (iCCA) remains unclear. Here, we generated a comprehensive atlas of the entire tumor microenvironment and delineated the multifaceted cell-cell interactions to decipher hypoxia-induced pro-tumor immune suppression. We discovered hypoxia is significantly associated with iCCA progression via the activation of HIF1A expression. Moreover, hypoxia-dependent PPARγ-mediated fatty acid oxidation in APOE+ TAMs promoted M2 macrophage polarization by activating the HIF1A-PPARG-CD36 axis. These polarized APOE+ TAMs recruited Treg cell infiltration via the CCL3-CCR5 pair to form an immunosuppressive microenvironment. APOE+ TAMs tended to co-localize spatially with Treg cells in the malignant tissue based on spatial transcriptome data and immunofluorescence analysis results. We identified tumor-reactive CXCL13+ CD8-PreTex with specific high expression of ENTPD1 and ITGAE, which acted as precursors of CD8-Tex and had higher cytotoxicity, lower exhaustion, and more vigorous proliferation. Consequently, CXCL13+ CD8-PreTex functioned as a positive regulator of antitumor immunity by expressing the pro-inflammatory cytokines IFNG and TNF, associated with a better survival outcome. Our study reveals the mechanisms involved in hypoxia-induced immunosuppression and suggests that targeting precursor-exhausted CXCL13+CD8+ T cells might provide a pratical immunotherapeutic approach.

6.
Oncogene ; 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38890429

RESUMO

The role of tumor-resident microbiota in modulating tumor immunity remains unclear. Here, we discovered an abundance of intra-tumoral bacteria, such us E.coli, residing and resulting in Colorectal cancer liver metastasis (CRLM). E.coli enhanced lactate production, which mediated M2 macrophage polarization by suppressing nuclear factor-κB -gene binding (NF-κB) signaling through retinoic acid-inducible gene 1 (RIG-I) lactylation. Lactylation of RIG-I suppressed recruitment of NF-κB to the Nlrp3 promoter in macrophages, thereby reducing its transcription. This loss of Nlrp3 affected the immunosuppressive activities of regulatory T cells (Tregs) and the antitumor activities of and CD8+ T cells. Small-molecule compound screening identified a RIG-I lactylation inhibitor that suppressed M2 polarization and sensitized CRLM to 5-fluorouracil (5-FU). Our findings suggest that tumor-resident microbiota may be a potential target for preventing and treating CRLM.

7.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 32(3): 789-793, 2024 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-38926968

RESUMO

OBJECTIVE: To investigate the relative expression level and clinical significance of LINC00475 in serum of patients with multiple myeloma (MM). METHODS: The expression of LINC00475 in serum of 108 MM patients and five MM cell lines including RPMI 8226, NCI-H929, U266, OPM2 and CAG were detected by real-time fluorescence quantitative PCR. The diagnostic value of LINC00475 in MM was evaluated by receiver operating characteristic (ROC) curve analysis. The correlation of LINC00475 with patients' characteristics was analyzed. RESULTS: Compared with control groups, the expression of LINC00475 was up-regulated in serum of MM patients and MM cell lines (all P < 0.05). ROC curve analysis showed that the optimal cut-off value of LINC00475 was 262.4, the area under curve (AUC) was 0.924(95%CI : 0.884-0.964), and sensitivity and specificity was 83.3% and 91.7%, respectively, which indicated that LINC00475 had good evaluation value in MM patients. Compared with low-LINC00475 expression group, patients in high-LINC00475 expression group had higher levels of ß2microglobulin (ß2-MG) and Cystatin C (Cys-C) but lower albumin (ALB) (all P < 0.05). Compared with MM patients with International Staging System (ISS) stage I, the expression level of LINC00475 was significantly higher in patients with stage II and III (both P < 0.05). CONCLUSION: LINC00475 is helpful to distinguish MM patients from healthy adults, which is correlated with the prognostic indicators such as ß2-MG, ALB, and ISS stage.


Assuntos
Mieloma Múltiplo , RNA Longo não Codificante , Humanos , Mieloma Múltiplo/genética , RNA Longo não Codificante/genética , Linhagem Celular Tumoral , Microglobulina beta-2 , Curva ROC , Relevância Clínica
8.
Nanoscale ; 16(25): 12007-12012, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38805180

RESUMO

Polyvinyl alcohol (PVA) fiber materials have gained immense recognition due to their good biocompatibility and wide applications. However, methods allowing the synergistic enhancement of mechanical strength and toughness of PVA fibers still remain a key challenge. To this end, we developed covalently cross-linked ultrastrong SiO2-loaded polyvinyl alcohol fibers via a microfluidic spinning chemistry strategy. The thermal stretching and annealing processes not only promote the ordered arrangement of molecules, but also facilitate the ring opening reaction and increase crystallinity. Thus, the resulting fiber has a high tensile strength of 866 MPa, a specific toughness of 288 J g-1 and a tensile strain of 80%. This work provides a covalent cross-linking reinforcement method to prepare ultrastrong composite fibers assisted by microfluidic spinning chemistry and thermal stretching, which would lead to the fabrication of mechanically strong fiber materials through a simple pathway.

9.
Clin Mol Hepatol ; 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38726504

RESUMO

Background/Aims: metabolic dysfunction-associated steatohepatitis (MASH) is an unmet clinical challenge due to the rapid increased occurrence but lacking approved drugs. Autophagy-related protein 16-like 1 (ATG16L1) plays an important role in the process of autophagy, which is indispensable for proper biogenesis of the autophagosome, but its role in modulating macrophage-related inflammation and metabolism during MASH has not been documented. Here, we aimed to elucidate the role of ATG16L1 in the progression of MASH. Methods: Expression analysis was performed with liver samples from human and mice. MASH models were induced in myeloid-specific Atg16l1-deficient and myeloid-specific Atg16l1-overexpressed mice by high-fat and high-cholesterol diet or methionine- and choline-deficient diet to explore the function and mechanism of macrophage ATG16L1 in MASH. Results: Macrophage-specific Atg16l1 knockout exacerbated MASH and inhibited energy expenditure, whereas macrophage-specific Atg16l1 transgenic overexpression attenuated MASH and promotes energy expenditure. Mechanistically, Atg16l1 knockout inhibited macrophage lipophagy, thereby suppressing macrophage ß-oxidation and decreasing the production of 4-hydroxynonenal (4-HNE), which further inhibited stimulator of interferon genes (STING) carbonylation. STING palmitoylation was enhanced, STING trafficking from the ER to the Golgi was promoted, and downstream STING signaling was activated, promoting proinflammatory and profibrotic cytokines secretion, resulting in hepatic steatosis and HSCs activation. Moreover, Atg16l1-deficiency enhanced macrophage phagosome ability but inhibited lysosome formation, engulfing mtDNA released by pyroptotic hepatocytes. Increased mtDNA promoted cGAS/STING signaling activation. Moreover, pharmacological promotion of ATG16L1 substantially blocked MASH progression. Conclusions: ATG16L1 suppresses MASH progression by maintaining macrophage lipophagy, restraining liver inflammation, and may be a promising therapeutic target for MASH management.

10.
Cartilage ; : 19476035241250198, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38747467

RESUMO

OBJECTIVE: Knee osteoarthritis (KOA) is a complex degenerative joint disease and a major cause of joint dysfunction. This study aimed to explore the function of hsa_circ_0007482 on inflammation, proliferation, differentiation, and apoptosis in KOA. DESIGN: Real-time quantitative polymerase chain reaction (PCR) was performed to detect the expression of circ_0007482, inflammatory factors, and differentiation-related molecules in KOA chondrocytes and interleukin (IL)-1ß-stimulated chondrocytes. The correlation between the circ_0007482 expression and inflammatory factors was analyzed by the Pearson method. KOA cell model was established using IL-1ß for 24 hours. The proliferation activity of chondrocytes was evaluated by CCK-8 assay, and cell apoptosis rate was assessed by flow cytometry. The downstream miRNA of circ_0007482 was validated using dual-luciferase reporter assay. RESULTS: The circ_0007482 expression was elevated in both KOA cartilage tissues and IL-1ß-treated chondrocytes and positively correlated with inflammatory factors expression. In comparison to the control group, IL-1ß treatment diminished chondrocyte proliferation abilities and increased cell apoptosis and inflammatory factors IL-6, IL-8, and tumor necrosis factor (TNF)-α mRNA expression. Inhibition of circ_0007482 partially improved IL-1ß-induced inflammatory reaction. Circ_0007482 could negatively regulate the expression of miR-558. CONCLUSIONS: Interfering of circ_0007482 might partially promote cell proliferation and differentiation, while inhibit cell apoptosis to improve joint injury by regulating miR-558 in IL-1ß-treated chondrocyte cell model.

11.
Plant Cell Environ ; 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38770581

RESUMO

Mitogen-activated protein kinase (MAPK) signalling cascades are functionally important signalling modules in eukaryotes. Transcriptome reprogramming of immune-related genes is a key process in plant immunity. Emerging evidence shows that plant MAPK cascade is associated with processing (P)-body components and contributes to transcriptome reprogramming of immune-related genes. However, it remains largely unknown how this process is regulated. Here, we show that OsMPK12, which is induced by Magnaporthe oryzae infection, positively regulates rice blast resistance. Further analysis revealed that OsMPK12 directly interacts with enhancer of mRNA decapping protein 4 (OsEDC4), a P-body-located protein, and recruits OsEDC4 to where OsMPK12 is enriched. Importantly, OsEDC4 directly interacts with two decapping complex members OsDCP1 and OsDCP2, indicating that OsEDC4 is a subunit of the mRNA decapping complex. Additionally, we found that OsEDC4 positively regulates rice blast resistance by regulating expression of immune-related genes and maintaining proper mRNA levels of some negatively-regulated genes. And OsMPK12 and OsEDC4 are also involved in rice growth and development regulation. Taken together, our data demonstrate that OsMPK12 positively regulates rice blast resistance via OsEDC4-mediated mRNA decay of immune-related genes, providing new insight into not only the new role of the MAPK signalling cascade, but also posttranscriptional regulation of immune-related genes.

12.
Acta Pharmacol Sin ; 45(7): 1406-1424, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38589687

RESUMO

Acute kidney injury (AKI) is often accompanied by uremic encephalopathy resulting from accumulation of uremic toxins in brain possibly due to impaired blood-brain barrier (BBB) function. Anionic uremic toxins are substrates or inhibitors of organic anionic transporters (OATs). In this study we investigated the CNS behaviors and expression/function of BBB OAT3 in AKI rats and mice, which received intraperitoneal injection of cisplatin 8 and 20 mg/kg, respectively. We showed that cisplatin treatment significantly inhibited the expressions of OAT3, synaptophysin and microtubule-associated protein 2 (MAP2), impaired locomotor and exploration activities, and increased accumulation of uremic toxins in the brain of AKI rats and mice. In vitro studies showed that uremic toxins neither alter OAT3 expression in human cerebral microvascular endothelial cells, nor synaptophysin and MAP2 expressions in human neuroblastoma (SH-SY5Y) cells. In contrast, tumour necrosis factor alpha (TNFα) and the conditioned medium (CM) from RAW264.7 cells treated with indoxyl sulfate (IS) significantly impaired OAT3 expression. TNFα and CM from IS-treated BV-2 cells also inhibited synaptophysin and MAP2 expressions in SH-SY5Y cells. The alterations caused by TNFα and CMs in vitro, and by AKI and TNFα in vivo were abolished by infliximab, a monoclonal antibody designed to intercept and neutralize TNFα, suggesting that AKI impaired the expressions of OAT3, synaptophysin and MAP2 in the brain via IS-induced TNFα release from macrophages or microglia (termed as IS-TNFα axis). Treatment of mice with TNFα (0.5 mg·kg-1·d-1, i.p. for 3 days) significantly increased p-p65 expression and reduced the expressions of Nrf2 and HO-1. Inhibiting NF-κB pathway, silencing p65, or activating Nrf2 and HO-1 obviously attenuated TNFα-induced downregulation of OAT3, synaptophysin and MAP2 expressions. Significantly increased p-p65 and decreased Nrf2 and HO-1 protein levels were also detected in brain of AKI mice and rats. We conclude that AKI inhibits the expressions of OAT3, synaptophysin and MAP2 due to IS-induced TNFα release from macrophages or microglia. TNFα impairs the expressions of OAT3, synaptophysin and MAP2 partly via activating NF-κB pathway and inhibiting Nrf2-HO-1 pathway.


Assuntos
Injúria Renal Aguda , Cisplatino , Indicã , Fator de Necrose Tumoral alfa , Animais , Injúria Renal Aguda/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Humanos , Camundongos , Masculino , Células RAW 264.7 , Ratos , Camundongos Endogâmicos C57BL , Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo , Ratos Sprague-Dawley , Sinaptofisina/metabolismo , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/efeitos dos fármacos , Uremia/metabolismo , Uremia/complicações , Linhagem Celular Tumoral
13.
mSphere ; 9(5): e0005724, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38687129

RESUMO

Endocytosis has been extensively studied in yeasts, where it plays crucial roles in growth, signaling regulation, and cell-surface receptor internalization. However, the biological functions of endocytosis in pathogenic filamentous fungi remain largely unexplored. In this study, we aimed to functionally characterize the roles of EdeA, an ortholog of the Saccharomyces cerevisiae endocytic protein Ede1, in Aspergillus fumigatus. EdeA was observed to be distributed as patches on the plasma membrane and concentrated in the subapical collar of hyphae, a localization characteristic of endocytic proteins. Loss of edeA caused defective hyphal polarity, reduced conidial production, and fewer sites of endocytosis initiations than that of the parental wild type. Notably, the edeA null mutant exhibited increased sensitivity to cell wall-disrupting agents, indicating a role for EdeA in maintaining cell wall integrity in A. fumigatus. This observation was further supported by the evidence showing that the thickness of the cell wall in the ΔedeA mutant increased, accompanied by abnormal activation of MpkA, a key component in the cell wall integrity pathway. Additionally, the ΔedeA mutant displayed increased pathogenicity in the Galleria mellonella wax moth infection model, possibly due to alterations in cell wall morphology. Site-directed mutagenesis identified the conserved residue E348 within the third EH (Eps15 homology) domain of EdeA as crucial for its subcellular localization and functions. In conclusion, our results highlight the involvement of EdeA in endocytosis, hyphal polarity, cell wall integrity, and pathogenicity in A. fumigatus. IMPORTANCE: Aspergillus fumigatus is a significant human pathogenic fungus known to cause invasive aspergillosis, a disease with a high mortality rate. Understanding the basic principles of A. fumigatus pathogenicity is crucial for developing effective strategies against this pathogen. Previous research has underscored the importance of endocytosis in the infection capacity of pathogenic yeasts; however, its biological function in pathogenic mold remains largely unexplored. Our characterization of EdeA in A. fumigatus sheds light on the role of endocytosis in the development, stress response, and pathogenicity of pathogenic molds. These findings suggest that the components of the endocytosis process may serve as potential targets for antifungal therapy.


Assuntos
Aspergillus fumigatus , Parede Celular , Endocitose , Proteínas Fúngicas , Hifas , Aspergillus fumigatus/patogenicidade , Aspergillus fumigatus/genética , Aspergillus fumigatus/metabolismo , Parede Celular/metabolismo , Parede Celular/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Hifas/genética , Hifas/crescimento & desenvolvimento , Virulência , Animais , Mariposas/microbiologia , Esporos Fúngicos/genética , Esporos Fúngicos/patogenicidade , Aspergilose/microbiologia
14.
Artigo em Inglês | MEDLINE | ID: mdl-38642326

RESUMO

BACKGROUND: Air volatile organic compounds (VOCs) cause allergic reaction mainly via the respiratory tract or skin. OBJECTIVE: This study aimed to investigate the association between daily visits by patients with urticaria and short-term changes in exposure to ambient air VOCs. METHODS: The dependent variable was information from patients with urticaria at a medical center in Kaohsiung, Taiwan, from 2014/01/01 to 2018/07/31. The multivariable model included one-day average 75th percentile values of air VOCs and meteorologic data retrieved from Taiwan Air Quality Monitoring Network database, and was analyzed using a case-crossover study design and conditional logistic regression. RESULTS: Total daily clinic visits for urticaria were significantly positively associated with higher levels of 4 VOCs (ethylbenzene, toluene, m-/p-xylene, and o-xylene (adjusted odds ratio (AOR: 1.03-1.28)) on the visit days, and 10 VOC levels on the fourth lag day (benzene, ethylbenzene, toluene, m-/p-xylene, o-xylene, 1,3,5-trimethylbenzene, n-hexane, methylcyclohexane, cyclohexane, and ethylene (AOR: 1.02-3.02)). Analyses of age and gender subgroups revealed that men showed resistance on the visit day, and women, older, and younger patients were more vulnerable. Men were influenced by higher benzene levels (AOR = 1.24) on the fourth lag day. Higher values of more than 6 VOCs on the fourth lag day significantly affected women, younger and older patients (AOR: 1.04-6.5). The most notable VOCs were methylcyclohexane (women AOR = 3.28, younger AOR = 3.82) and 1,3,5-trimethylbenzene (women AOR = 2.77, older AOR = 6.5) on the fourth lag day, which had the lowest concentrations but highest influence. CONCLUSION: The concentration of certain air VOCs significantly affected daily visits for urticaria.

15.
Life Sci ; 344: 122564, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38492922

RESUMO

AIMS: Prolyl hydroxylase domain 2 (PHD2), encoded by the Egln1 gene, serves as a pivotal regulator of the hypoxia-inducible factor (HIF) pathway and acts as a cellular oxygen sensor. Somatic inactivation of Phd2 in mice results in polycythemia and congestive heart failure. However, due to the embryonic lethality of Phd2 deficiency, its role in development remains elusive. Here, we investigated the function of two egln1 paralogous genes, egln1a and egln1b, in zebrafish. MAIN METHODS: The egln1 null zebrafish were generated using the CRISPR/Cas9 system. Quantitative real-time PCR assays and Western blot analysis were employed to detect the effect of egln1 deficiency on the hypoxia signaling pathway. The hypoxia response of egln1 mutant zebrafish were assessed by analyzing heart rate, gill agitation frequency, and blood flow velocity. Subsequently, o-dianisidine staining and in situ hybridization were used to investigate the role of egln1 in zebrafish hematopoietic function. KEY FINDINGS: Our data show that the loss of egln1a or egln1b individually has no visible effects on growth rate. However, the egln1a; egln1b double mutant displayed significant growth retardation and elevated mortality at around 2.5 months old. Both egln1a-null and egln1b-null zebrafish embryo exhibited enhanced tolerance to hypoxia, systemic hypoxic response that include hif pathway activation, increased cardiac activity, and polycythemia. SIGNIFICANCE: Our research introduces zebrafish egln1 mutants as the first congenital embryonic viable systemic vertebrate animal model for PHD2, providing novel insights into hypoxic signaling and the progression of PHD2- associated disease.


Assuntos
Prolina Dioxigenases do Fator Induzível por Hipóxia , Hipóxia , Policitemia , Peixe-Zebra , Animais , Camundongos , Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia , Prolina Dioxigenases do Fator Induzível por Hipóxia/genética , Prolina Dioxigenases do Fator Induzível por Hipóxia/metabolismo , Policitemia/genética , Pró-Colágeno-Prolina Dioxigenase/genética , Peixe-Zebra/genética , Peixe-Zebra/metabolismo
16.
Hypertens Res ; 47(5): 1273-1287, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38438725

RESUMO

m6A (N6­methyladenosine) is the most common and abundant apparent modification in mRNA of eukaryotes. The modification of m6A is regulated dynamically and reversibly by methyltransferase (writer), demethylase (eraser), and binding protein (reader). It plays a significant role in various processes of mRNA metabolism, including regulation of transcription, maturation, translation, degradation, and stability. Pulmonary arterial hypertension (PAH) is a malignant cardiopulmonary vascular disease characterized by abnormal proliferation of pulmonary artery smooth muscle cells. Despite the existence of several effective and targeted therapies, there is currently no cure for PAH and the prognosis remains poor. Recent studies have highlighted the crucial role of m6A modification in cardiovascular diseases. Investigating the role of RNA m6A methylation in PAH could provide valuable insights for drug development. This review aims to explore the mechanism and function of m6A in the pathogenesis of PAH and discuss the potential targeting of RNA m6A methylation modification as a treatment for PAH.


Assuntos
Adenosina , Adenosina/análogos & derivados , Hipertensão Arterial Pulmonar , Humanos , Metilação , Adenosina/metabolismo , Hipertensão Arterial Pulmonar/genética , Hipertensão Arterial Pulmonar/metabolismo , Animais , RNA Mensageiro/metabolismo , RNA Mensageiro/genética , Metiltransferases/metabolismo , Metiltransferases/genética , Metilação de RNA
17.
Appl Environ Microbiol ; 90(4): e0000824, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38506527

RESUMO

Currently, the L-malic acid titer achieved through Aspergillus niger fermentation reaches 201 g/L, meeting industrial demands satisfactorily. However, the co-presence of structurally similar fumaric acid and succinic acid in fermentation products suggests a theoretical potential for further improvement in L-malic acid production. In the tricarboxylic acid cycle, fumarate reductase mediates the conversion of succinic acid to fumaric acid. Subsequently, fumarase catalyzes the conversion of fumaric acid to L-malic acid. Notably, both enzymatic reactions are reversible. Our investigation revealed that A. niger contains only one mitochondria-located fumarase FumA. Employing CRISPR-Cas9 technology, we performed a replacement of the fumA promoter with a doxycycline-induced promoter Tet. Under non-inducing condition, the conditional strain exhibited increased levels of fumaric acid and succinic acid. It strongly suggests that FumA mainly promotes the flow of fumaric acid to L-malic acid. Furthermore, a promoter PmfsA that is exclusively activated in a fermentation medium by calcium carbonate was identified through RNA-sequencing screening. Utilizing PmfsA to regulate fumA expression led to a 9.0% increase in L-malic acid titer, an 8.75% increase in yield (glucose to L-malic acid), and an 8.86% enhancement in productivity. This research serves as a significant step toward expediting the industrialization of L-malic acid synthesis via biological fermentation. Additionally, it offers valuable insights for the biosynthesis of other organic acids.IMPORTANCEThis study focuses on enhancing L-malic acid synthesis by modifying the tricarboxylic acid cycle within the mitochondria of Aspergillus niger. We emphasize the significant role of fumarase in converting fumaric acid into L-malic acid, enhancing our understanding of metabolic pathways in A. niger. The precise regulation of fumA is highlighted as a key factor in enhancing L-malic acid production. Furthermore, this research introduces a stringent conditional promoter (PmfsA), exclusively activated by CaCO3. The utilization of PmfsA for fumA expression resulted in heightened L-malic acid titers. The progress in metabolic engineering and bioprocess optimization holds promise for expediting industrial L-malic acid synthesis via biological fermentation. Moreover, it carries implications for the biosynthesis of various other organic acids.


Assuntos
Aspergillus niger , Fumarato Hidratase , Fumaratos , Aspergillus niger/genética , Aspergillus niger/metabolismo , Fumarato Hidratase/genética , Fumarato Hidratase/metabolismo , Malatos/metabolismo , Ácido Succínico
18.
Front Nutr ; 11: 1383808, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38496792

RESUMO

[This corrects the article DOI: 10.3389/fnut.2022.1016943.].

19.
Adv Sci (Weinh) ; 11(20): e2306297, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38477534

RESUMO

Disrupted gastrointestinal (GI) motility is highly prevalent in patients with inflammatory bowel disease (IBD), but its potential causative role remains unknown. Herein, the role and the mechanism of impaired GI motility in colitis pathogenesis are investigated. Increased colonic mucosal inflammation is found in patients with chronic constipation (CC). Mice with GI dysmotility induced by genetic mutation or chemical insult exhibit increased susceptibility to colitis, dependent on the gut microbiota. GI dysmotility markedly decreases the abundance of Lactobacillus animlalis and increases the abundance of Akkermansia muciniphila. The reduction in L. animlalis, leads to the accumulation of linoleic acid due to compromised conversion to conjugated linoleic acid. The accumulation of linoleic acid inhibits Treg cell differentiation and increases colitis susceptibility via inducing macrophage infiltration and proinflammatory cytokine expression in macrophage. Lactobacillus and A. muciniphila abnormalities are also observed in CC and IBD patients, and mice receiving fecal microbiota from CC patients displayed an increased susceptibility to colitis. These findings suggest that GI dysmotility predisposes host to colitis development by modulating the composition of microbiota and facilitating linoleic acid accumulation. Targeted modulation of microbiota and linoleic acid metabolism may be promising to protect patients with motility disorder from intestinal inflammation.


Assuntos
Colite , Modelos Animais de Doenças , Microbioma Gastrointestinal , Motilidade Gastrointestinal , Ácido Linoleico , Animais , Microbioma Gastrointestinal/fisiologia , Camundongos , Ácido Linoleico/metabolismo , Colite/metabolismo , Colite/microbiologia , Colite/induzido quimicamente , Humanos , Camundongos Endogâmicos C57BL , Masculino , Constipação Intestinal/metabolismo , Constipação Intestinal/microbiologia , Feminino , Akkermansia , Lactobacillus/metabolismo
20.
Synth Syst Biotechnol ; 9(2): 277-284, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38496318

RESUMO

Aspergillus niger is an efficient cell factory for organic acids production, particularly l-malic acid, through genetic manipulation. However, the traditional method of collecting A. niger spores for inoculation is labor-intensive and resource-consuming. In our study, we used the CRISPR-Cas9 system to replace the promoter of brlA, a key gene in Aspergillus conidiation, with a xylose-inducible promoter xylP in l-malic acid-producing A. niger strain RG0095, generating strain brlAxylP. When induced with xylose in submerged liquid culture, brlAxylP exhibited significant upregulation of conidiation-related genes. This induction allowed us to easily collect an abundance of brlAxylP spores (>7.1 × 106/mL) in liquid xylose medium. Significantly, the submerged conidiation approach preserves the substantial potential of A. niger as a foundational cellular platform for the biosynthesis of organic acids, including but not limited to l-malic acid. In summary, our study offers a simplified submerged conidiation strategy to streamline the preparation stage and reduce labor and material costs for industrial organic acid production using Aspergillus species.

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