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1.
BMC Ophthalmol ; 24(1): 203, 2024 Apr 30.
Article En | MEDLINE | ID: mdl-38684941

BACKGROUND: This study aims to investigate the morphologic features of the crystalline lens in Primary Angle Closure Disease (PACD) patients with zonular instability during cataract surgery using the swept-source CASIA 2 Anterior Segment-Optical Coherence Tomography (AS-OCT) system. METHODS: A total of 398 eyes (125 PACD eyes with zonular instability, 133 PACD eyes with zonular stability, and 140 cataract patient controls) of 398 patients who underwent cataract surgery combined or not glaucoma surgery between January 2021 and January 2023 were enrolled. The crystalline lens parameters were measured by CASIA2 AS-OCT. Then, logistic regression was performed to evaluate the risk factors associated with zonular instability. RESULTS: The results revealed that PACD eyes had a more anterior lens equator position, a steeper anterior curvature of lens, shorter Axial Length (AL), shallower Anterior Chamber Distance (ACD), higher Lens Vault (LV) and thicker Lens Thickness (LT), when compared to eyes in the cataract control group. Furthermore, PACD eyes in the zonular instability group had steeper front R, front Rs and Front Rf, flatter back Rf, thicker lens anterior part thickness, higher lens anterior-to-posterior part thickness ratios, shallower ACD, and greater LV, when compared to PACD eyes with zonular stability. The logistic regression analysis, which was adjusted for age and gender, revealed that zonular instability was positively correlated with anterior part thickness, lens anterior-to-posterior part thickness ratio, and LV, but was negatively correlated with lens anterior radius and ACD. CONCLUSION: Steeper anterior curvature, increased lens anterior part thickness, higher anterior-to-posterior part thickness ratio, shallower ACD, and greater LV are the anatomic features of PACD eyes associated with zonular instability.


Anterior Eye Segment , Glaucoma, Angle-Closure , Lens, Crystalline , Tomography, Optical Coherence , Humans , Tomography, Optical Coherence/methods , Glaucoma, Angle-Closure/physiopathology , Glaucoma, Angle-Closure/diagnosis , Female , Male , Aged , Middle Aged , Anterior Eye Segment/diagnostic imaging , Anterior Eye Segment/pathology , Lens, Crystalline/diagnostic imaging , Lens, Crystalline/pathology , Retrospective Studies , Intraocular Pressure/physiology , Visual Acuity/physiology
3.
Biotechnol Biofuels Bioprod ; 16(1): 118, 2023 Jul 24.
Article En | MEDLINE | ID: mdl-37488642

BACKGROUND: Induction of cellulase in cellulolytic fungi Trichoderma reesei is strongly activated by cellulosic carbon sources. The transport of cellulosic inducer and the perception of inducing signal is generally considered as the critical process for cellulase induction, that the inducing signal would be perceived by a sugar transporter/transceptor in T. reesei. Several sugar transporters are coexpressed during the induction stage, but which function they serve and how they work collaboratively are still difficult to elucidate. RESULTS: In this study, we found that the constitutive expression of the cellulose response transporter-like protein CRT2 (previously identified as putative lactose permease TRE77517) improves cellulase induction on a cellulose, cellobiose or lactose medium. Functional studies indicate that the membrane-bound CRT2 is not a transporter of cellobiose, lactose or glucose in a yeast system, and it also does not affect cellobiose and lactose utilization in T. reesei. Further study reveals that CRT2 has a slightly similar function to the cellobiose transporter CRT1 in cellulase induction. Overexpression of CRT2 led to upregulation of CRT1 and the key transcription factor XYR1. Moreover, overexpression of CRT2 could partially compensate for the function loss of CRT1 on cellulase induction. CONCLUSIONS: Our study uncovers the novel function of CRT2 in cellulase induction collaborated with CRT1 and XYR1, possibly as a signal transductor. These results deepen the understanding of the influence of sugar transporters in cellulase production.

4.
Appl Microbiol Biotechnol ; 107(7-8): 2483-2499, 2023 Apr.
Article En | MEDLINE | ID: mdl-36917273

Increasing cellulase production in cellulolytic fungus Trichoderma reesei is of interest for biofuels and biorefineries. Previous studies indicated that secreted protein was occasionally accumulated in vacuoles; this phenomenon has also been reported in T. reesei. Therefore, alleviating vacuolar transport seems to be a promising strategy for improving cellulase production in T. reesei. Herein, we found that knockout of vps10, vps13, and vps21, among 11 vacuolar protein sorting factors, improved cellulase production in T. reesei. The filter paper activity in Δvps10, Δvps13, and Δvps21 increased by 1.28-, 2.45-, and 2.11-fold than that of the parent strain. Moreover, the ß-glucosidase activity in Δvps13 and Δvps21 increased by 3.22- and 3.56-fold after 6 days of fermentation. Furthermore, we also found that the vacuolar trafficking towards vacuoles was partially impaired in three knockout mutants, and disruption of vps13 alleviated the autophagy process. These results indicated that alleviated transport and degradation towards vacuole in Δvps10, Δvps13, and Δvps21 might improve cellulase production. Of note, the expression of cellulase genes in Δvps13 and Δvps21 was dramatically increased in the late induction phase compared to the parent. These results suggested that Vps13 and Vps21 might influence the cellulase production at transcription level. And further transcriptome analysis indicated that increased cellulase gene expression might be attributed to the differential expression of sugar transporters. Our study unravels the effect of alleviating vacuolar transport through knockout vps10, vps13, and vps21 for efficient cellulase secretion, providing new clues for higher cellulase production in T. reesei. KEY POINTS: • Disruption of vps10, vps13 or vps21 improves cellulase production • Vacuolar transport is impaired in three vps KO mutants • Deletion of vps13 or vps21 increases the transcript of cellulase genes in late stage.


Cellulase , Hypocreales , Trichoderma , Cellulase/genetics , Cellulase/metabolism , Trichoderma/genetics , Trichoderma/metabolism , Fungal Proteins/genetics , Fungal Proteins/metabolism , Hypocreales/metabolism
5.
J Med Virol ; 95(1): e28407, 2023 01.
Article En | MEDLINE | ID: mdl-36519597

To control the ongoing COVID-19 pandemic, a variety of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines have been developed. However, the rapid mutations of SARS-CoV-2 spike (S) protein may reduce the protective efficacy of the existing vaccines which is mainly determined by the level of neutralizing antibodies targeting S. In this study, we screened prevalent S mutations and constructed 124 pseudotyped lentiviral particles carrying these mutants. We challenged these pseudoviruses with sera vaccinated by Sinovac CoronaVac and ZF2001 vaccines, two popular vaccines designed for the initial strain of SARS-CoV-2, and then systematically assessed the susceptivity of these SARS-CoV-2 variants to the immune sera of vaccines. As a result, 14 S mutants (H146Y, V320I + S477N, V382L, K444R, L455F + S477N, L452M + F486L, F486L, Y508H, P521R, A626S, S477N + S698L, A701V, S477N + T778I, E1144Q) were found to be significantly resistant to neutralization, indicating reduced protective efficacy of the vaccines against these SARS-CoV-2 variants. In addition, F486L and Y508H significantly enhanced the utilization of human angiotensin-converting enzyme 2, suggesting a potentially elevated infectivity of these two mutants. In conclusion, our results show that some prevalent S mutations of SARS-CoV-2 reduced the protective efficacy of current vaccines and enhance the infectivity of the virus, indicating the necessity of vaccine renewal and providing direction for the development of new vaccines.


COVID-19 , SARS-CoV-2 , Humans , COVID-19/prevention & control , Antibodies, Viral , Neutralization Tests , Spike Glycoprotein, Coronavirus , Virus Internalization , Pandemics , Antibodies, Neutralizing , Mutation
6.
Brief Bioinform ; 24(1)2023 01 19.
Article En | MEDLINE | ID: mdl-36567622

Genomic recombination is an important driving force for viral evolution, and recombination events have been reported for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the Coronavirus Disease 2019 pandemic, which significantly alter viral infectivity and transmissibility. However, it is difficult to identify viral recombination, especially for low-divergence viruses such as SARS-CoV-2, since it is hard to distinguish recombination from in situ mutation. Herein, we applied information theory to viral recombination analysis and developed VirusRecom, a program for efficiently screening recombination events on viral genome. In principle, we considered a recombination event as a transmission process of ``information'' and introduced weighted information content (WIC) to quantify the contribution of recombination to a certain region on viral genome; then, we identified the recombination regions by comparing WICs of different regions. In the benchmark using simulated data, VirusRecom showed a good balance between precision and recall compared to two competing tools, RDP5 and 3SEQ. In the detection of SARS-CoV-2 XE, XD and XF recombinants, VirusRecom providing more accurate positions of recombination regions than RDP5 and 3SEQ. In addition, we encapsulated the VirusRecom program into a command-line-interface software for convenient operation by users. In summary, we developed a novel approach based on information theory to identify viral recombination within highly similar sequences, providing a useful tool for monitoring viral evolution and epidemic control.


COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , Information Theory , Phylogeny , Recombination, Genetic
7.
Foods ; 11(21)2022 Nov 01.
Article En | MEDLINE | ID: mdl-36360082

In this study, a potential producer of prebiotics, a novel endo-polygalacturonase pePGA from Penicillium rolfsii BM-6, was successfully expressed in Komagataella phaffii, characterized and applied to produce pectic oligosaccharides. The optimum temperature and pH of pePGA were 60 °C and 6.0. The purified recombinant enzyme showed a good pH stability and was stable from pH 3.5 to 8.0. The Km, Vmax and kcat values of pePGA were 0.1569 g/L, 12,273 µmol/min/mg and 7478.4 s-1, respectively. More importantly, pePGA-POS, the pePGA hydrolysis products from commercial pectin, had good prebiotic and antibacterial activities in vitro. The pePGA-POS was able to significantly promote the growth of probiotics; meanwhile, the growth of Escherichia coli JM109, Staphylococcus aureus and Bacillus subtilis 168 was effectively inhibited by pePGA-POS. In addition, pePGA-POS also had the DPPH radical scavenging capacity. These properties of pePGA-POS make pePGA attractive for the production of prebiotics.

8.
Clin Respir J ; 16(4): 276-283, 2022 Apr.
Article En | MEDLINE | ID: mdl-35289083

OBJECTIVE: We conducted a meta-analysis to systematic assess the diagnostic value of computed tomography (CT)-based pulmonary artery to aorta (PA:A) ratio measurement in COPD with pulmonary hypertension (COPD-PH). METHODS: Published studies referring to diagnostic accuracy of PA:A ratio for COPD-PH were screened out from PubMed, Embase, Web of science, China National Knowledge databases (CNKI), Wan fang databases, and VIP databases. We used bivariate random-effects model to estimate pooled sensitivity (SEN), specificity (SPE), positive and negative likelihood ratios (PLR and NLR, respectively), and diagnostic odds ratios (DOR). Summary receiver operating characteristic (SROC) curves and area under the curve (AUC) were also calculated to summarize the aggregate diagnostic performance. RESULTS: Nine eligible studies were included and the pooled SEN was 69% (95% CI: 59 ~ 78), SPE was 85% (95% CI: 77 ~ 90), PLR was 4.5 (95% CI: 2.8 ~ 7.5), and NLR was 0.36 (95% CI: 0.26 ~ 0.51), respectively. DOR reached 13.00 (95% CI: 6.00 ~ 28.00), and value of AUC was 0.84 (95% CI: 0.81 ~ 0.87). Subgroup analysis indicated that when the value of PA:A ratio was equal or greater than one (PA/A ≥ 1), the combined SEN, SPE, AUC, and DOR was 69%, 89%, 0.90, and 19.65, respectively. CONCLUSIONS: PA:A ratio is helpful for appraisal of COPD-PH, and PA/A ≥ 1 possessed prominent diagnostic accuracy.


Hypertension, Pulmonary , Pulmonary Disease, Chronic Obstructive , Aorta , Humans , Hypertension, Pulmonary/diagnostic imaging , Pulmonary Artery/diagnostic imaging , Pulmonary Disease, Chronic Obstructive/complications , Pulmonary Disease, Chronic Obstructive/diagnostic imaging , Sensitivity and Specificity , Tomography, X-Ray Computed
9.
Microb Cell Fact ; 20(1): 131, 2021 Jul 12.
Article En | MEDLINE | ID: mdl-34247591

BACKGROUND: Thermotolerant yeast has outstanding potential in industrial applications. Komagataella phaffii (Pichia pastoris) is a common cell factory for industrial production of heterologous proteins. RESULTS: Herein, we obtained a thermotolerant K. phaffii mutant G14 by mutagenesis and adaptive evolution. G14 exhibited oxidative and thermal stress cross-tolerance and high heterologous protein production efficiency. The reactive oxygen species (ROS) level and lipid peroxidation in G14 were reduced compared to the parent. Oxidative stress response (OSR) and heat shock response (HSR) are two major responses to thermal stress, but the activation of them was different in G14 and its parent. Compared with the parent, G14 acquired the better performance owing to its stronger OSR. Peroxisomes, as the main cellular site for cellular ROS generation and detoxification, had larger volume in G14 than the parent. And, the peroxisomal catalase activity and expression level in G14 was also higher than that of the parent. Excitingly, the gene knockdown of CAT encoding peroxisomal catalase by dCas9 severely reduced the oxidative and thermal stress cross-tolerance of G14. These results suggested that the augmented OSR was responsible for the oxidative and thermal stress cross-tolerance of G14. Nevertheless, OSR was not strong enough to protect the parent from thermal stress, even when HSR was initiated. Therefore, the parent cannot recover, thereby inducing the autophagy pathway and resulting in severe cell death. CONCLUSIONS: Our findings indicate the importance of peroxisome and the significance of redox balance in thermotolerance of yeasts.


Heat-Shock Response , Oxidative Stress , Peroxisomes/metabolism , Reactive Oxygen Species/metabolism , Saccharomycetales/physiology , Antioxidants/metabolism , Autophagy , Catalase/metabolism , Directed Molecular Evolution , Fungal Proteins/genetics , Gene Expression Profiling , Genes, Fungal , Heat-Shock Proteins/genetics , Lipid Peroxidation , Oxidation-Reduction , Saccharomycetales/genetics , Thermotolerance , Transcription Factors/genetics , Ubiquitin/genetics
10.
Biotechnol Biofuels ; 14(1): 160, 2021 Jul 20.
Article En | MEDLINE | ID: mdl-34284814

BACKGROUND: Pichia pastoris (syn. Komagataella phaffii) is an important yeast system for heterologous protein expression. A robust P. pastoris mutant with oxidative and thermal stress cross-tolerance was acquired in our previous study. The robust mutant can express a 2.5-fold higher level of lipase than its wild type (WT) under methanol induction conditions. RESULTS: In this study, we found that the robust mutant not only can express a high level of lipase, but also can express a high level of other heterogeneous proteins (e.g., green fluorescence protein) under methanol induction conditions. Additionally, the intracellular reactive oxygen species (ROS) levels in the robust mutant were lower than that in the WT under methanol induction conditions. To figure out the difference of cellular response to methanol between the WT and the robust mutant, RNA-seq was detected and compared. The results of RNA-seq showed that the expression levels of genes related to antioxidant, MAPK pathway, ergosterol synthesis pathway, transcription factors, and the peroxisome pathway were upregulated in the robust mutant compared to the WT. The upregulation of these key pathways can improve the oxidative stress tolerance of strains and efficiently eliminate cellular ROS. Hence, we inferred that the high heterologous protein expression efficiency in the robust mutant may be due to its enhanced oxidative stress tolerance. Promisingly, we have indeed increased the expression level of lipase up to 1.6-fold by overexpressing antioxidant genes in P. pastoris. CONCLUSIONS: This study demonstrated the impact of methanol on the expression levels of genes in P. pastoris and emphasized the contribution of oxidative stress tolerance on heterologous protein expression in P. pastoris. Our results shed light on the understanding of protein expression mechanism in P. pastoris and provided an idea for the rational construction of robust yeast with high expression ability.

11.
Biomolecules ; 11(6)2021 06 07.
Article En | MEDLINE | ID: mdl-34200257

Water content is an important factor in lipase-catalyzed reactions in organic media but is frequently ignored in the study of lipases by molecular dynamics (MD) simulation. In this study, Candida antarctica lipase B, Candida rugosa lipase and Rhizopus chinensis lipase were used as research models to explore the mechanisms of lipase in micro-aqueous organic solvent (MAOS) media. MD simulations indicated that lipases in MAOS systems showed unique conformations distinguished from those seen in non-aqueous organic solvent systems. The position of water molecules aggregated on the protein surface in MAOS media is the major determinant of the unique conformations of lipases and particularly impacts the distribution of hydrophilic and hydrophobic amino acids on the lipase surface. Additionally, two maxima were observed in the water-lipase radial distribution function in MAOS systems, implying the formation of two water shells around lipase in these systems. The energy landscapes of lipases along solvent accessible areas of catalytic residues and the minimum energy path indicated the dynamic open states of lipases in MAOS systems differ from those in other solvent environments. This study confirmed the necessity of considering the influence of the microenvironment on MD simulations of lipase-catalyzed reactions in organic media.


Cellular Microenvironment/physiology , Computational Biology/methods , Lipase/chemistry , Molecular Dynamics Simulation , Water/chemistry , Basidiomycota/chemistry , Basidiomycota/metabolism , Fungal Proteins/chemistry , Fungal Proteins/metabolism , Hydrophobic and Hydrophilic Interactions , Lipase/analysis , Lipase/metabolism , Protein Structure, Secondary , Protein Structure, Tertiary , Saccharomycetales/chemistry , Saccharomycetales/metabolism , Water/metabolism
12.
J Agric Food Chem ; 69(14): 4263-4275, 2021 Apr 14.
Article En | MEDLINE | ID: mdl-33797235

Most fungal lipases contain a propeptide, which is very important for their function and substrate selectivity. In the present study, Rhizopus chinensis lipase (RCL) was used as a research model to explore the mechanism of the propeptide of the lipase. Conventional molecular dynamics (MD) and metadynamics simulations were used to explore the mechanism by which the propeptide affects the activity of the lipase, which was subsequently verified by mutation experiments. MD simulations indicated that the propeptide had an inhibitory effect on the lid movement of RCL and found a key region (Val5-Thr10) on the propeptide. Subsequently, site-directed mutations were created in this region. The mutations enhanced the lipase catalytic efficiency to 700% and showed the potential for the propeptide to shift the substrate specificity of RCL. The specificity and activity of RCL mutants also had similar trends to wild-type RCL toward triglycerides with varying chain lengths. The mutual corroboration of simulation and site-directed mutagenesis results revealed the vital role of the key propeptide region in the catalytic activity and substrate specificity of the lipase.


Lipase , Rhizopus , Lipase/genetics , Lipase/metabolism , Molecular Dynamics Simulation , Rhizopus/genetics , Rhizopus/metabolism , Substrate Specificity
13.
Biotechnol Biofuels ; 14(1): 90, 2021 Apr 08.
Article En | MEDLINE | ID: mdl-33832521

BACKGROUND: Filamentous fungus Trichoderma reesei has been widely used as a workhorse for cellulase and xylanase productions. Xylanase has been reported as the crucial accessory enzyme in the degradation of lignocellulose for higher accessibility of cellulase. In addition, the efficient hydrolysis of xylan needs the co-work of multiple xylanolytic enzymes, which rise an increasing demand for the high yield of xylanase for efficient biomass degradation. RESULTS: In this study, a xylanase hyper-producing system in T. reesei was established by tailoring two transcription factors, XYR1 and ACE1, and homologous overexpression of the major endo-xylanase XYNII. The expressed xylanase cocktail contained 5256 U/mL xylanase activity and 9.25 U/mL ß-xylosidase (pNPXase) activity. Meanwhile, the transcription level of the xylanolytic genes in the strain with XYR1 overexpressed was upregulated, which was well correlated with the amount of XYR1-binding sites. In addition, the higher expression of associated xylanolytic enzymes would result in more efficient xylan hydrolysis. Besides, 2310-3085 U/mL of xylanase activities were achieved using soluble carbon source, which was more efficient and economical than the traditional strategy of xylan induction. Unexpectedly, deletion of ace1 in C30OExyr1 did not give any improvement, which might be the result of the disturbed function of the complex formed between ACE1 and XYR1. The enzymatic hydrolysis of alkali pretreated corn stover using the crude xylanase cocktails as accessory enzymes resulted in a 36.64% increase in saccharification efficiency with the ratio of xylanase activity vs FPase activity at 500, compared to that using cellulase alone. CONCLUSIONS: An efficient and economical xylanase hyper-producing platform was developed in T. reesei RUT-C30. The novel platform with outstanding ability for crude xylanase cocktail production would greatly fit in biomass degradation and give a new perspective of further engineering in T. reesei for industrial purposes.

14.
World J Clin Cases ; 9(3): 697-706, 2021 Jan 26.
Article En | MEDLINE | ID: mdl-33553411

BACKGROUND: Juvenile-onset primary open-angle glaucoma (JOAG), characterized by severe elevation of intraocular pressure and optic neuropathy prior to the age of 40, is a rare subtype of primary open-angle glaucoma. Several genetic mutations have been associated with JOAG. CASE SUMMARY: The proband patient was a young male, diagnosed with primary open-angle glaucoma at the age of 27. The patient and his unaffected parents who have been excluded from classic genetic mutations for primary open-angle glaucoma were included to explore for other possible genetic variants through whole genome sequencing and bioinformatics analysis. In this trio, we found two heterozygous variants inherited from the parents in the proband: c.281G>A, p.Arg94His in OLFM2 and c.177C>G, p.Ile59Met in SIX6. Both genetic mutations are predicted through bioinformatics analysis to replace evolutionary conserved amino acids, therefore rendering a pathogenic effect on proteins. In contrast, very low frequencies for these genetic mutations were recorded in most common control databases. CONCLUSION: This is the first report on coinherited mutations of OLFM2 and SIX6 in a JOAG family, which shows the complexity of JOAG inheritance. Large-scale clinical screening and molecular functional investigations on these coinherited mutations are imperative to improve our understanding of the development of JOAG.

15.
Int J Biol Macromol ; 173: 1-12, 2021 Mar 15.
Article En | MEDLINE | ID: mdl-33476612

The catalytic mechanism of most lipases involves a step called "interfacial activation" which significantly increases lipases activity beyond the critical micellar concentration (CMC) of substrate. In the present study, Rhizopus chinensis lipase (RCL) was used as a research model to explore the mechanism of lipase interfacial activation beyond the CMC. Molecular dynamic (MD) simulations indicated the open- and closed-lid transitions and revealed that Phe113 was the critical site for RCL activation by its dynamic flipping. Such putative switch affecting interfacial activation has not been reported in lipase so far. The function of Phe113 was subsequently verified by mutation experiments. The F113W mutant increases the lipase catalytic efficiency (1.9 s-1·µM-1) to 280% at the optimum temperature (40 °C) and pH 8.5 with the addition of 0.12 µg protein in the 200 µL reaction system. MD simulations indicated that the fast flipping rate from the closed to the open state, the high open state proportion, and the exposure of the catalytic triad are the main reasons for the lipase activation. The mutual corroboration of simulations and site-directed mutagenesis results revealed the vital role of Phe113 in the lipase activation.


Butyrates/chemistry , Fungal Proteins/chemistry , Lipase/chemistry , Phenylalanine/chemistry , Rhizopus/chemistry , Binding Sites , Biocatalysis , Butyrates/metabolism , Cloning, Molecular , Escherichia coli/genetics , Escherichia coli/metabolism , Fungal Proteins/genetics , Fungal Proteins/metabolism , Gene Expression , Genetic Vectors/chemistry , Genetic Vectors/metabolism , Hydrogen-Ion Concentration , Kinetics , Lipase/genetics , Lipase/metabolism , Molecular Dynamics Simulation , Phenylalanine/metabolism , Protein Binding , Protein Conformation, alpha-Helical , Protein Conformation, beta-Strand , Protein Interaction Domains and Motifs , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Rhizopus/enzymology , Substrate Specificity , Temperature , Thermodynamics , Water/chemistry
16.
Bioresour Bioprocess ; 8(1): 107, 2021 Oct 22.
Article En | MEDLINE | ID: mdl-38650205

The filamentous fungus Trichoderma reesei has been widely used for cellulase production that has extensive applications in green and sustainable development. Increasing costs and depletion of fossil fuels provoke the demand for hyper-cellulase production in this cellulolytic fungus. To better manipulate T. reesei for enhanced cellulase production and to lower the cost for large-scale fermentation, it is wise to have a comprehensive understanding of the crucial factors and complicated biological network of cellulase production that could provide new perspectives for further exploration and modification. In this review, we summarize recent progress and give an overview of the cellular process of cellulase production in T. reesei, including the carbon source-dependent cellulase induction, complicated transcriptional regulation network, and efficient protein assembly and trafficking. Among that, the key factors involved in cellulase production were emphasized, shedding light on potential perspectives for further engineering.

17.
Chin Med J (Engl) ; 133(21): 2586-2594, 2020 Nov 05.
Article En | MEDLINE | ID: mdl-32852382

Clinical ophthalmologists consider each retinal disease as a completely unique entity. However, various retinal diseases, such as uveitis, age-related macular degeneration, diabetic retinopathy, and primary open-angle glaucoma, share a number of common pathogenetic pathways. Whether a retinal disease initiates from direct injury to the blood-retinal barrier (BRB) or a defect/injury to retinal neurons or glia that impairs the BRB secondarily, the BRB is a pivotal point in determining the prognosis as self-limiting and recovering, or developing and progressing to a clinical phenotype. The present review summarizes our current knowledge on the physiology and cellular and molecular pathology of the BRB, which underlies its pivotal role in the initiation and development of common retinal diseases.


Diabetic Retinopathy , Macular Degeneration , Retinal Diseases , Blood-Retinal Barrier , Humans , Phenotype
18.
Medicine (Baltimore) ; 99(8): e19246, 2020 Feb.
Article En | MEDLINE | ID: mdl-32080128

INTRODUCTION: Chromosome 6pter-p24 deletion syndrome (OMIM #612582) is a rare genetic disorder characterized by deletion of the distal part of 6p. Human 6p deletion syndromes result in a variety of congential malformations. PATIENT CONCERNS: The fetus was the fourth child born to healthy non-consanguineous parents with no relevant family history. DIAGNOSIS: The fetus was diagnosed with 6pter-p24 deletion syndrome through prenatal ultrasound, magnetic resonance imaging, and chromosomal microarray analysis. The fetus had brain, skeletal, and heart malformations. The fetus was cytogenetically normal. Chromosomal microarray analysis detected an interstitial 7.999Mb deletion within the 6p25.1p24.3 region of chromosome 6. INTERVENTIONS: There was no treatment for the fetus. OUTCOMES: Pregnancy was terminated. CONCLUSIONS: To the author's knowledge, the present case is one of the first to report the prenatal diagnosis of 6pter-p24 deletion syndrome in a fetus. No published reports have described the diagnosis of 6pter-p24 deletion syndrome using multiple technologies during the antenatal period; therefore, our findings may provide a reference for other clinicians. The clinical features and pathophysiology of this prenatal diagnosis are discussed.


Eye Abnormalities/diagnosis , Fetus , Hearing Loss/diagnosis , Heart Defects, Congenital/diagnosis , Hypertelorism/diagnosis , Prenatal Diagnosis/methods , Chromosome Deletion , Chromosomes, Human, Pair 6 , Female , Humans , Pregnancy
19.
J Microbiol Biotechnol ; 30(2): 196-205, 2020 Feb 28.
Article En | MEDLINE | ID: mdl-31752069

In this study, the acidic lipase from Aspergillus niger (ANL) was homologously expressed in A. niger. The expression of ANL was significantly improved by the expression of the native ANL with the introns, the addition of the Kozak sequence and the optimization of the signal sequences. When the cDNA sequence of ANL fused with the glaA signal was expressed under the gpdA promoter in A. niger, no lipase activity could be detected. We then tried to improve the expression by using the full-length ANL gene containing three introns, and the lipase activity in the supernatant reached 75.80 U/ml, probably as a result of a more stable mRNA structure. The expression was further improved to 100.60 U/ml by introducing a Kozak sequence around the start codon due to a higher translation efficiency. Finally, the effects of three signal sequences including the cbhI signal, the ANL signal and the glaA signal on the lipase expression were evaluated. The transformant with the cbhI signal showed the highest lipase activity (314.67 U/ml), which was 1.90-fold and 3.13-fold higher than those with the ANL signal and the glaA signal, respectively. The acidic lipase was characterized and its highest activity was detected at pH 3.0 and a temperature of 45°C. These results provided promising strategies for the production of the acidic lipase from A. niger.


Aspergillus niger/enzymology , Aspergillus niger/genetics , Gene Expression Regulation, Bacterial , Lipase/genetics , Lipase/metabolism , Enzyme Activation , Enzyme Stability , Hydrogen-Ion Concentration , Lipase/isolation & purification , Plasmids/genetics , Temperature , Transformation, Bacterial
20.
Colloids Surf B Biointerfaces ; 184: 110501, 2019 Dec 01.
Article En | MEDLINE | ID: mdl-31541891

Supported cross-linked enzyme aggregates were prepared by immobilization of Candida antarctica lipase B onto hydrophobic surface of octyl-modified mesocellular foams (MCFs-C8). Oxidized sodium alginate was used as a substitute for traditional glutaraldehyde. Supported cross-linked enzyme aggregates using oxidized sodium alginate (SA-CLEAs@MCFs-C8) exhibited significantly improved thermal stability and organic solvents tolerance compared to the free lipase, lipase adsorbed onto MCFs-C8 and supported cross-linked enzyme aggregates using glutaraldehyde (G-CLEAs@MCFs-C8). Then immobilized lipases were employed for biodiesel production by transesterification of soybean oil with methanol. In the optimization condition, SA-CLEAs@MCFs-C8 were quite stable and still showed high fatty acid methyl esters (FAME) yield after 5 repeated cycles (from 89% to 78%), whereas MCFs-C8-CALB retained 67% FAME yield (about 72% for G-CLEAs@MCFs-C8).


Alginates/chemistry , Cross-Linking Reagents/chemistry , Fungal Proteins/chemistry , Lipase/chemistry , Metal-Organic Frameworks/chemistry , Adsorption , Alginates/metabolism , Cross-Linking Reagents/metabolism , Enzymes, Immobilized/chemistry , Enzymes, Immobilized/metabolism , Fungal Proteins/metabolism , Hydrophobic and Hydrophilic Interactions , Lipase/metabolism , Metal-Organic Frameworks/metabolism , Molecular Structure , Oxidation-Reduction , Particle Size , Protein Aggregates , Surface Properties , Temperature
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