Displaying publications 21 - 40 of 47 in total

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  1. Physicochemical properties and anti-diabetic ability of polysaccharides from a thinned peach fruit
    Zhou L, Song Y, Jiang Y, Wei Y, Jiang S, Chen Y, et al.
    Food Funct, 2023 Oct 02;14(19):8876-8892.
    PMID: 37698234 DOI: 10.1039/d3fo03041e
    Thinned peach fruit is a by-product with abundant yields. However, it is barely utilized. This study aimed to study the physicochemical properties and anti-diabetic ability of polysaccharides (PPSs) from a thinned peach fruit to investigate its application potential. Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) characterizations were performed together with tests to determine rheology properties, monosaccharide composition, and molecular weight of the obtained polysaccharide. Moreover, the antioxidant activity, α-amylase inhibitory activity, binding abilities to bile salts, and effects on type 2 diabetic mice were analyzed. The results indicated that PPS consisted of two components with molecular weights of 287.38 kDa and 12.02 kDa, accounting for 89.83% and 10.17% of the composition, respectively. The dominant monosaccharides were galactose, galacturonic acid, and arabinose, exhibiting α-configurations. The concentration was positively related to the viscosity of PPS. As the temperature was increased from 25 °C to 37 °C and the pH from 2.0 to 7.0, the viscosity decreased. The IC50 values for scavenging DPPH and ABTS were around 0.22 and 1.47 mg mL-1. Also, PPS could inhibit α-amylase ability and bind bile salts. The administration of PPS significantly inhibited emaciation, organ damage, improved oral glucose tolerance and insulin resistance, enhanced the content of short-chain fatty acids (SCFAs), and regulated blood lipid profiles and the composition and structure of colon microbiota in type-2 diabetic mice. These results provide new evidence for the potential of PPS as a bioactive ingredient with anti-diabetic properties for use in the food industry.
  2. Fulltext Molecular Mechanism of Citrate Efflux by the Mitochondrial Citrate Transporter CT in Filamentous Fungus Mucor circinelloides WJ11
    Yang W, Dong S, Yang J, Mohamed H, Shah AM, Nazir Y, et al.
    Front Microbiol, 2021;12:673881.
    PMID: 34054781 DOI: 10.3389/fmicb.2021.673881
    The mitochondrial citrate transporter (MCT) plays an important role in citrate efflux from the mitochondria in eukaryotes, and hence provides a direct correlation between carbohydrate metabolism and lipid synthesis. Our previous studies on transporters confirmed the presence of two MCTs (TCT and CT) in oleaginous Mucor circinelloides WJ11 associated with high lipid accumulation. However, the molecular mechanism of citrate efflux from the mitochondria by MCT in M. circinelloides is still unclear. To study the citrate transport mechanism of CT, the citrate transporter gene was expressed in Escherichia coli, and its product was purified. The citrate transport activity of the protein was studied in CT reconstituted liposomes. Our results showed high efficiency of CT for [14C] citrate/citrate exchange with K m 0.01 mM at 25°C. Besides citrate, other molecules such as oxaloacetate, malate, fumarate, succinate aconitate, oxoadipate, isocitrate, and glutamate also promote citrate transport. In addition, the ct overexpression and knockout plasmids were constructed and transferred into M. circinelloides WJ11, and the mitochondria were isolated, and the transport activity was studied. Our findings showed that in the presence of 10 mM malate, the mitochondria of ct-overexpressing transformant showed 51% increase in the efflux rate of [14C] citrate, whereas the mitochondria of the ct-knockout transformant showed 18% decrease in citrate efflux compared to the mitochondria of wild-type WJ11. This study provided the first mechanistic evidence of citrate efflux from the mitochondria by citrate transporter in oleaginous filamentous fungus M. circinelloides, which is associated with high lipid accumulation.
  3. Fulltext Emerging respiratory infections threatening public health in the Asia-Pacific region: A position paper of the Asian Pacific Society of Respirology
    Park S, Park JY, Song Y, How SH, Jung KS, Respiratory Infections Assembly of the APSR
    Respirology, 2019 Jun;24(6):590-597.
    PMID: 30985968 DOI: 10.1111/resp.13558
    In past decades, we have seen several epidemics of respiratory infections from newly emerging viruses, most of which originated in animals. These emerging infections, including severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV) and the pandemic influenza A(H1N1) and avian influenza (AI) viruses, have seriously threatened global health and the economy. In particular, MERS-CoV and AI A(H7N9) are still causing infections in several areas, and some clustering of cases of A(H5N1) and A(H7N9) may imply future possible pandemics. Additionally, given the inappropriate use of antibiotics and international travel, the spread of carbapenem-resistant Gram-negative bacteria is also a significant concern. These infections with epidemic or pandemic potential present a persistent threat to public health and a huge burden on healthcare services in the Asia-Pacific region. Therefore, to enable efficient infection prevention and control, more effective international surveillance and collaboration systems, in the context of the 'One Health' approach, are necessary.
  4. Fulltext Coculturing of Mucor plumbeus and Bacillus subtilis bacterium as an efficient fermentation strategy to enhance fungal lipid and gamma-linolenic acid (GLA) production
    Mohamed H, Awad MF, Shah AM, Sadaqat B, Nazir Y, Naz T, et al.
    Sci Rep, 2022 Jul 30;12(1):13111.
    PMID: 35908106 DOI: 10.1038/s41598-022-17442-2
    This study aimed to improve lipid and gamma-linolenic acid (GLA) production of an oleaginous fungus, Mucor plumbeus, through coculturing with Bacillus subtilis bacteria, optimising the environmental and nutritional culture conditions, and scaling them for batch fermentation. The maximum levels of biomass, lipid, fatty acid, and GLA in a 5 L bioreactor containing cellobiose and ammonium sulfate as the optimal carbon and nitrogen sources, respectively, achieved during the coculturing processes were 14.5 ± 0.4 g/L, 41.5 ± 1.3, 24 ± 0.8, and 20 ± 0.5%, respectively. This strategy uses cellobiose in place of glucose, decreasing production costs. The nutritional and abiotic factor results suggest that the highest production efficiency is achieved at 6.5 pH, 30 °C temperature, 10% (v/v) inoculum composition, 200 rpm agitation speed, and a 5-day incubation period. Interestingly, the GLA concentration of cocultures (20.0 ± 0.5%) was twofold higher than that of monocultures (8.27 ± 0.11%). More importantly, the GC chromatograms of cocultures indicated the presence of one additional peak corresponding to decanoic acid (5.32 ± 0.20%) that is absent in monocultures, indicating activation of silent gene clusters via cocultivation with bacteria. This study is the first to show that coculturing of Mucor plumbeus with Bacillus subtilis is a promising strategy with industrialisation potential for the production of GLA-rich microbial lipids and prospective biosynthesis of new products.
  5. An interpretable (explainable) model based on machine learning and SHAP interpretation technique for mapping wind erosion hazard
    Gholami H, Darvishi E, Moradi N, Mohammadifar A, Song Y, Li Y, et al.
    Environ Sci Pollut Res Int, 2024 Nov 15.
    PMID: 39546243 DOI: 10.1007/s11356-024-35521-x
    Soil erosion by wind poses a significant threat to various regions across the globe, such as drylands in the Middle East and Iran. Wind erosion hazard maps can assist in identifying the regions of highest wind erosion risk and are a valuable tool for the mitigation of its destructive consequences. This study aims to map wind erosion hazards by developing an interpretable (explainable) model based on machine learning (ML) and Shapley additive exPlanation (SHAP) interpretation techniques. Four ML models, namely random forest (RF), support vector machine (SVM), extreme gradient boosting (XGB), and quadratic discriminant analysis (QDA) were used. Thirteen features associated with wind erosion were mapped spatially and then subjected to a multivariate adaptive regression spline (MARS) feature selection algorithm, and then, tolerance coefficient (TC) and variance inflation factor (VIF) statistical tests were used to explore multicollinearity among the variables. MARS analysis shows that eight features consisting of elevation (or DEM), soil bulk density, precipitation, aspect, slope, soil sand content, vegetation cover (or NDVI), and lithology were the most effective for wind erosion, while no collinearity existed among these variables. The ML models were used for ranking the effective features, and the research introduces the application of an interpretable ML model for the interpretation of predictive model's output. The ranking of effective features by RF-as the most typical ML model-revealed that elevation and soil bulk density were the two most important features. According to the area under the receiver operating characteristic curve (AUROC) (with a value > 90%) and precision-recall (PR) (with a value > 90%) curves, all four ML models performed with great accuracy. According to the PR curve, the SVM model performed slightly better than others, and its results revealed that 20.9%, 23%, and 16.6% of the total area in Hormozgan Province is characterized by moderate, high, and very high hazard classes to wind erosion, respectively. SHAP revealed that soil sand content and elevation are the most important variables contributing to the predictive model output. Overall, our research is one of the pioneering applications of interpretable ML models in mapping wind erosion hazards in Southern Iran. We recommend that future research should address the aspect of interpretability in order to better understand predictive model outputs.
  6. Fabrication, characterization, and application of BiOI@ZIF-8 nanocomposite for enhanced photocatalytic degradation of acetaminophen from aqueous solutions under UV-vis irradiation
    Mengting Z, Duan L, Zhao Y, Song Y, Xia S, Gikas P, et al.
    J Environ Manage, 2023 Nov 01;345:118772.
    PMID: 37597373 DOI: 10.1016/j.jenvman.2023.118772
    This work investigates the use of novel BiOI@ZIF-8 nanocomposite for the removal of acetaminophen (Ace) from synthetic wastewater. The samples were analyzed using FTIR, XRD, XPS, DRS, PL, FESEM-EDS, and ESR techniques. The effects of the loading capacity of ZIF-8 on the photocatalytic oxidation performance of bismuth oxyiodide (BiOI) were studied. The photocatalytic degradation of Ace was maximized by optimizing pH, reaction time and the amount of photocatalyst. On this basis, the removal mechanisms of the target pollutant by the nanocomposite and its photodegradation pathways were elucidated. Under optimized conditions of 1 g/L of composite, pH 6.8, and 4 h of reaction time, it was found that the BiOI@ZIF-8 (w/w = 1:0.01) nanocomposite exhibited the highest Ace removal (94%), as compared to that of other loading ratios at the same Ace concentration of 25 mg/L. Although this result was encouraging, the treated wastewater still did not satisfy the required statutory of 0.2 mg/L. It is suggested that the further biological processes need to be adopted to complement Ace removal in the samples. To sustain its economic viability for wastewater treatment, the spent composite still could be reused for consecutive five cycles with 82% of regeneration efficiency. Overall, this series of work shows that the nanocomposite was a promising photocatalyst for Ace removal from wastewater samples.
  7. Understanding the Role of Surface Chemistry in Nanocellulose Kink Formation: A Case Study of TEMPO-Mediated Oxidation
    Zhen Y, Peng C, Gao H, Bai L, Song Y, Gao P, et al.
    Biomacromolecules, 2024 Dec 09;25(12):7767-7776.
    PMID: 39526987 DOI: 10.1021/acs.biomac.4c01082
    This study found that the sources of cellulose have a significant effect on the parameters related to the kinks present in nanocellulose. During nanocellulose preparation, 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO)-mediated oxidation induced partial depolymerization on whole cellulose and made the amorphous regions more susceptible to consequent mechanical treatment irrespective of cellulose sources. However, plant cellulose microfibrils were prone to break into shorter nanocellulose with fewer kinks, while bacterial and tunicate cellulose were more likely to bend rather than break, thus leading to the generation of more kinks. The kinks did not show significant effects on the size, crystallinity index, and thermal properties of nanocellulose for each cellulose source, though the kink numbers were positively related to the mechanical performance of nanocellulose. Collectively, this study elucidated the kink formation mechanisms and clarified the effects of kinks on nanocellulose performance, thus providing new insights into understanding the source and behaviors of microdefects present in nanocellulose.
  8. Metabolic engineering of Mucor circinelloides to improve astaxanthin production
    Naz T, Saeed T, Ullah S, Nazir Y, Assefa M, Liu Q, et al.
    World J Microbiol Biotechnol, 2024 Nov 02;40(12):374.
    PMID: 39487367 DOI: 10.1007/s11274-024-04181-x
    Astaxanthin is a bioactive natural pigment with antioxidant properties. It has extensive applications within the industrial sector as well as in human and animal health. Mucor circinelloides is a zygomycete fungus that accumulates β-carotene as the main carotenoid compound. M. circinelloides is a well-known model organism among Mucorales for studying carotenogenesis in fungi, which makes it a promising candidate for the biotechnological production of carotenoids. In this study, β-carotene hydroxylase (crtR-B) and ketolase (bkt) genes (codon-optimized) were coexpressed from Haematococcus pluvialis in M. circinelloides using two potent promoters gpd1 and zrt1 respectively to generate an astaxanthin-producing biofactory. Following 72 h of cultivation, the recombinant M. circinelloides Mc-57 obtained in this study produced 135 ± 8 µg/g of astaxanthin. This is the highest reported amount in M. circinelloides to date. The mRNA levels of crtR-B and bkt in Mc-57 were assayed using RT-qPCR. These levels showed a 5.7-fold increase at 72 h and a 5.5-fold increase at 24 h, respectively, compared to the control strain. This demonstrated the successful overexpression of both genes, which correlated with the production of astaxanthin in the Mc-57. Moreover, the addition of glutamate (2 g/L) and mevalonate (15 mM) resulted in an increase in astaxanthin production in the recombinant strain. The results showed that the combined addition of these metabolic precursors resulted in 281 ± 20 µg/g of astaxanthin, which is 2.08-fold higher than the control medium (135 ± 8 µg/g). The addition of metabolic precursors also positively impacted the biomass growth of Mc-57, reaching 11.2 ± 0.57 g/L compared to 9.1 ± 0.23 g/L (control medium). The study successfully addressed the challenge of balancing the accumulation of astaxanthin with biomass growth, which has been regarded as common bottleneck in the metabolic engineering of microbial cells. The development of a recombinant fungal strain of M. circinelloides not only increased astaxanthin content. Additionally, it provided a foundation for further improvement of the biotechnological production of astaxanthin in M. circinelloides.
  9. The interplay of transcriptional regulator SREBP1 with AMPK promotes lipid biosynthesis in Mucor circinelloides WJ11
    Naz T, Zhao XY, Li S, Saeed T, Ullah S, Nazir Y, et al.
    Biochim Biophys Acta Mol Cell Biol Lipids, 2025 Mar;1870(2):159592.
    PMID: 39733936 DOI: 10.1016/j.bbalip.2024.159592
    SREBP1 is a transcription factor that influences lipogenesis by regulating key genes associated with lipid biosynthesis, while AMPK, modulates lipid metabolism by regulating acetyl-CoA carboxylase. The exact role of these metabolic regulators in oleaginous microbes remains unclear. This study identified and manipulated the genes encoding SREBP1 (sre1) and α1 subunit of AMPK (ampk-α1) in Mucor circinelloides WJ11. Individual overexpression of sre1 yielded 32.5 % lipids and 21 g/L biomass, while ampk-α1 deletion combined with sre1 overexpression yielded 42.5 % lipids and 25 g/L biomass in mutant strains. This increase correlated with upregulated expression of key lipogenic genes and enzyme activity, enhancing lipid production and biomass. These surges were correlated with the increased mRNA levels of key genes (acl, acc1, acc2, cme1, fas1, g6pdh1, g6pdh2 and 6pgdh2). Enzyme activity analysis further showed that upregulation of ACL, ACC, ME, FAS, G6PDH and 6PGDH might provide more precursors and NADPH for lipid biosynthesis in sre1 overexpressing strains. Conversely, the activities of these genes and enzymes were markedly downregulated in sre1 deleted mutants consistent with lower lipid production and biomass than the control. These findings open new avenues for research by exploring the coordinated role of sre1 and ampk-α1 in lipid metabolism in M. circinelloides.
  10. The association between psychological strain and suicidal behaviors among college students: A mental health survey in Jilin Province, Northeast China
    Song Y, Bai W, Wang M, Liu X, Zhang L, Yu W, et al.
    J Affect Disord, 2019 12 01;259:195-200.
    PMID: 31446380 DOI: 10.1016/j.jad.2019.08.042
    BACKGROUND: Suicide is a major global mental health problem among college students. The aim of the current study was to explore the association between the psychological strains of the strain theory of suicide and suicidal behaviors among college students.

    METHODS: Participants comprised 1912 college students (16-28 years old, 47.2% female) from three universities in Jilin Province, China, who completed the self-report assessments of psychological strains (40 items Psychological Strains Scale) and suicidal behaviors (Suicidal Behaviors Questionnaire-Revised). The demographic characteristics included four variables: health status, psychological status, academic status and economic status.

    RESULTS: Approximately 15.0% (286/1912) of participants were classified as having suicide risk, based on the cut-off scores of the SBQ-R. The prevalence of suicidal behaviors among males and females was 11.9% (120/1009) and 18.4% (166/903), respectively. Value strain (OR = 1.075, 95%CI: 1.057-1.094), aspiration strain (OR = 1.082, 95%CI: 1.064-1.101), deprivation strain (OR = 1.073, 95%CI: 1.052-1.093), and coping strain (OR = 1.095, 95%CI: 1.075-1.116) were risk factors for suicidality in college students. Coping strain (OR = 1.050, 95%CI: 1.023-1.077) was still positively associated with suicide risk in multivariate logistic regression. Logistic regression analysis indicated that coping strain had the highest correlation with suicidal behaviors.

    LIMITATIONS: The directionality of the relationships cannot be deduced because this study is cross-sectional.

    CONCLUSION: This study confirms a strong association between psychological strains and suicidal behaviors in college students. Some measures can be taken to reduce psychological strains to mitigate suicide risk among college students. More studies investigating coping strain among college students are warranted.

  11. Deletion of Plasma Membrane Malate Transporters Increased Lipid Accumulation in the Oleaginous Fungus Mucor circinelloides WJ11
    Yang J, Cánovas-Márquez JT, Li P, Li S, Niu J, Wang X, et al.
    J Agric Food Chem, 2021 Aug 25;69(33):9632-9641.
    PMID: 34428900 DOI: 10.1021/acs.jafc.1c03307
    Malate as an important intermediate metabolite, its subcellular location, and concentration have a significant impact on fungal lipid metabolism. Previous studies showed that the mitochondrial malate transporter plays an important role in lipid accumulation in Mucor circinelloides by manipulating intracellular malate concentration. However, the role of plasma membrane malate transporters in oleaginous fungi remains unexplored. Therefore, in this work, two plasma membrane malate transporters "2-oxoglutarate:malate antiporters" (named SoDIT-a and SoDIT-b) of M. circinelloides WJ11 were deleted, and the consequences in growth capacity, lipid accumulation, and metabolism were analyzed. The results showed that deletion of sodit-a or/and sodit-b reduced the extracellular malate, confirming that the products of both genes participate in malate transportation. In parallel, the lipid contents in mutants increased approximately 10-40% higher than that in the control strain, suggesting that the defect in plasma membrane malate transport results in an increase of malate available for lipid biosynthesis. Furthermore, transcriptional analysis showed that the expression levels of multiple key genes involved in the lipid biosynthesis were also increased in the knockout mutants. To the best of our knowledge, this is the first report that demonstrated the association between plasma membrane malate transporters and lipid accumulation in M. circinelloides.
  12. Fulltext Role of Snf-β in lipid accumulation in the high lipid-producing fungus Mucor circinelloides WJ11
    Nosheen S, Naz T, Yang J, Hussain SA, Fazili ABA, Nazir Y, et al.
    Microb Cell Fact, 2021 Feb 27;20(1):52.
    PMID: 33639948 DOI: 10.1186/s12934-021-01545-y
    BACKGROUND: Mucor circinelloides WJ11 is a high-lipid producing strain and an excellent producer of γ-linolenic acid (GLA) which is crucial for human health. We have previously identified genes that encode for AMP-activated protein kinase (AMPK) complex in M. circinelloides which is an important regulator for lipid accumulation. Comparative transcriptional analysis between the high and low lipid-producing strains of M. circinelloides showed a direct correlation in the transcriptional level of AMPK genes with lipid metabolism. Thus, the role of Snf-β, which encodes for β subunit of AMPK complex, in lipid accumulation of the WJ11 strain was evaluated in the present study.

    RESULTS: The results showed that lipid content of cell dry weight in Snf-β knockout strain was increased by 32 % (from 19 to 25 %). However, in Snf-β overexpressing strain, lipid content of cell dry weight was decreased about 25 % (from 19 to 14.2 %) compared to the control strain. Total fatty acid analysis revealed that the expression of the Snf-β gene did not significantly affect the fatty acid composition of the strains. However, GLA content in biomass was increased from 2.5 % in control strain to 3.3 % in Snf-β knockout strain due to increased lipid accumulation and decreased to 1.83 % in Snf-β overexpressing strain. AMPK is known to inactivate acetyl-CoA carboxylase (ACC) which catalyzes the rate-limiting step in lipid synthesis. Snf-β manipulation also altered the expression level of the ACC1 gene which may indicate that Snf-β control lipid metabolism by regulating ACC1 gene.

    CONCLUSIONS: Our results suggested that Snf-β gene plays an important role in regulating lipid accumulation in M. circinelloides WJ11. Moreover, it will be interesting to evaluate the potential of other key subunits of AMPK related to lipid metabolism. Better insight can show us the way to manipulate these subunits effectively for upscaling the lipid production. Up to our knowledge, it is the first study to investigate the role of Snf-β in lipid accumulation in M. circinelloides.

  13. In vitro assessment on effect of duodenal contents on the lead (Pb(2+)) binding capacity of two probiotic bacterial strains
    Xing S, Song Y, Liang JB, Faseleh Jahromi M, Shokryazda P, Mi J, et al.
    Ecotoxicol Environ Saf, 2017 May;139:78-82.
    PMID: 28113114 DOI: 10.1016/j.ecoenv.2017.01.016
    In vitro Lead (Pb(2+)) binding capacity of two probiotic bacteria strains, namely Bifidobacterium longumBB79 and Lactobacillus pentosusITA23, was assessed following incubation with the intestinal contents (IC) of laying hens. Results of this study demonstrated that IC treatment significantly enhanced (P<0.01) Pb(2+) binding capacity of both bacterial strains. Fourier transform infrared analysis indicated that several functional groups (O-H or N-H, C-H, C˭O, C-O, and C-O-C) on the bacteria cell wall involved in metal ion binding were altered after IC incubation, and new groups appeared between the 3700cm(-1) and 4000cm(-1)bands. Transmission electron microscopy demonstrated that after incubation with IC, unidentified IC components created new binding sites on the bacterial cell surface. These particles also changed the mechanism of Pb(2+) binding of the two strains from intracellular accumulation to extracellular adsorption.
  14. Influence of antenatal glucocorticoid on preterm lamb diaphragm
    Mahzabin T, Pillow JJ, Pinniger GJ, Bakker AJ, Noble PB, White RB, et al.
    Pediatr Res, 2017 Sep;82(3):509-517.
    PMID: 28388600 DOI: 10.1038/pr.2017.99
    BackgroundPregnant women at a high risk of preterm delivery receive glucocorticoids to accelerate fetal lung maturation and surfactant synthesis. However, the effect of antenatal steroids on the developing diaphragm remains unclear. We hypothesized that maternal betamethasone impairs the fetal diaphragm, and the magnitude of the detrimental effect increases with longer duration of exposure. We aimed to determine how different durations of fetal exposure to maternal betamethasone treatment influence the fetal diaphragm at the functional and molecular levels.MethodsDate-mated merino ewes received intramuscular injections of saline (control) or two doses of betamethasone (5.7 mg) at an interval of 24 h commencing either 2 or 14 days before delivery. Preterm lambs were killed after cesarean delivery at 121-day gestational age. In vitro contractile measurements were performed on the right hemidiaphragm, whereas molecular/cellular analyses used the left costal diaphragm.ResultsDifferent durations of fetal exposure to maternal betamethasone had no consistent effect on the protein metabolic pathway, expression of glucocorticoid receptor and its target genes, cellular oxidative status, or contractile properties of the fetal lamb diaphragm.ConclusionThese data suggest that the potential benefits of betamethasone exposure on preterm respiratory function are not compromised by impaired diaphragm function after low-dose maternal intramuscular glucocorticoid exposure.
  15. Revealing holistic metabolic responses associated with lipid and docosahexaenoic acid (DHA) production in Aurantiochytrium sp. SW1
    Prabhakaran P, Raethong N, Thananusak R, Nazir MYM, Sapkaew C, Soommat P, et al.
    Biochim Biophys Acta Mol Cell Biol Lipids, 2023 May;1868(5):159306.
    PMID: 36907245 DOI: 10.1016/j.bbalip.2023.159306
    Aurantiochytrium sp. SW1, a marine thraustochytrid, has been regarded as a potential candidate as a docosahexaenoic acid (DHA) producer. Even though the genomics of Aurantiochytrium sp. are available, the metabolic responses at a systems level are largely unknown. Therefore, this study aimed to investigate the global metabolic responses to DHA production in Aurantiochytrium sp. through transcriptome and genome-scale network-driven analysis. Of a total of 13,505 genes, 2527 differentially expressed genes (DEGs) were identified in Aurantiochytrium sp., unravelling the transcriptional regulations behinds lipid and DHA accumulation. The highest number of DEG were found for pairwise comparison between growth phase and lipid accumulating phase where a total of 1435 genes were down-regulated with 869 genes being up-regulated. These uncovered several metabolic pathways that contributing in DHA and lipid accumulation including amino acid and acetate metabolism which involve in the generation of crucial precursors. Upon applying network-driven analysis, hydrogen sulphide was found as potential reporter metabolite that could be associated with the genes related to acetyl-CoA synthesis for DHA production. Our findings suggest that the transcriptional regulation of these pathways is a ubiquitous feature in response to specific cultivation phases during DHA overproduction in Aurantiochytrium sp. SW1.
  16. Fulltext Redirecting Metabolic Flux towards the Mevalonate Pathway for Enhanced β-Carotene Production in M. circinelloides CBS 277.49
    Naz T, Nazir Y, Nosheen S, Ullah S, Halim H, Fazili ABA, et al.
    Biomed Res Int, 2020;2020:8890269.
    PMID: 33457420 DOI: 10.1155/2020/8890269
    Carotenoids produced by microbial sources are of industrial and medicinal importance due to their antioxidant and anticancer properties. In the current study, optimization of β-carotene production in M. circinelloides strain 277.49 was achieved using response surface methodology (RSM). Cerulenin and ketoconazole were used to inhibit fatty acids and the sterol biosynthesis pathway, respectively, in order to enhance β-carotene production by diverting metabolic pool towards the mevalonate pathway. All three variables used in screening experiments were found to be significant for the production of β-carotene. The synergistic effect of the C/N ratio, cerulenin, and ketoconazole was further evaluated and optimized for superior β-carotene production using central composite design of RSM. Our results found that the synergistic combination of C/N ratios, cerulenin, and ketoconazole at different concentrations affected the β-carotene productions significantly. The optimal production medium (std. order 11) composed of C/N 25, 10 μg/mL cerulenin, and 150 mg/L ketoconazole, producing maximum β-carotene of 4.26 mg/L (0.43 mg/g) which was 157% greater in comparison to unoptimized medium (1.68 mg/L, 0.17 mg/g). So, it was concluded that metabolic flux had been successfully redirected towards the mevalonate pathway for enhanced β-carotene production in CBS 277.49.
  17. Correction of Lying Ear and Aesthetic Modification of Helix and Ear Lobule with Hyaluronic Acid Filler Injection: Experience in Chinese Patients
    Li Y, Dong W, Zhang L, Yang Y, Song Y, Shi N, et al.
    Aesthet Surg J, 2024 Jan 25.
    PMID: 38271268 DOI: 10.1093/asj/sjae010
    BACKGROUND: Large and long ears are regarded as symbols of wealth and health in eastern Asian culture, patients with lying ears wish their ears to be more exposed and prominent. Surgeries correcting lying ears have been documented.

    OBJECTIVES: We report correction of lying ears and aesthetic modification of helix and ear lobule with HA injections.

    METHODS: We performed HA injections at auriculocephalic sulcus (AS) to increase cranioauricular angle (CA) and correct lying ears. The injections at helix and lobule were case-specific. The CA was measured and photographs were taken at baseline and 1-, 3-, 6-, and 10-month follow-ups. Efficacy was assessed using a 5-point global aesthetic improvement scale (GAIS). Adverse events (AEs) were recorded.

    RESULTS: Forty-six patients (92 ears) received HA injections and completed follow-ups. Instant correction outcomes were observed. Sixteen (34.8%) patients received one touch-up injection, whose clinical efficacy persisted for 1 to 1.5 years. The GAIS for over 90% of cases with touch-up treatment was "very much improved" or "much improved" at all follow-ups. The GAIS for over 70% of cases without touch-up treatment was "very much improved" or "much improved" at 1, 3, and 6-month follow-ups. CA increased significantly compared with the baseline. Patients also reported "more V-shaped face shape" and "lifted jawline" effects. No serious AEs occurred.

    CONCLUSIONS: As an alternative technique to surgeries, HA filler injections at AS effectively corrected lying ears. This technique produced immediate, long-lasting, and aesthetically pleasing results. The side effects and downtime were minimal.

  18. Early nodulin 93 protein gene: essential for induction of somatic embryogenesis in oil palm
    Chan PL, Rose RJ, Abdul Murad AM, Zainal Z, Ong PW, Ooi LC, et al.
    Plant Cell Rep, 2020 Nov;39(11):1395-1413.
    PMID: 32734510 DOI: 10.1007/s00299-020-02571-7
    KEY MESSAGE: Transcript profiling during the early induction phase of oil palm tissue culture and RNAi studies in a model somatic embryogenesis system showed that EgENOD93 expression is essential for somatic embryogenesis. Micropropagation of oil palm through tissue culture is vital for the generation of superior and uniform elite planting materials. Studies were carried out to identify genes to distinguish between leaf explants with the potential to develop into embryogenic or non-embryogenic callus. Oil palm cDNA microarrays were co-hybridized with cDNA probes of reference tissue, separately with embryo forming (media T527) and non-embryo (media T694) forming leaf explants sampled at Day 7, Day 14 and Day 21. Analysis of the normalized datasets has identified 77, 115 and 127 significantly differentially expressed genes at Day 7, Day 14, and Day 21, respectively. An early nodulin 93 protein gene (ENOD93), was highly expressed at Day 7, Day 14, and Day 21 and in callus (media T527), as assessed by RT-qPCR. Validation of EgENOD93 across tissue culture lines of different genetic background and media composition showed the potential of this gene as an embryogenic marker. In situ RNA hybridization and functional characterization in Medicago truncatula provided additional evidence that ENOD93 is essential for somatic embryogenesis. This study supports the suitability of EgENOD93 as a marker to predict the potential of leaf explants to produce embryogenic callus. Crosstalk among stresses, auxin, and Nod-factor like signalling molecules likely induces the expression of EgENOD93 for embryogenic callus formation.
  19. Broadband Nonlinear Photonics in Few-Layer Borophene
    Ma C, Yin P, Khan K, Tareen AK, Huang R, Du J, et al.
    Small, 2021 Jan 27.
    PMID: 33502109 DOI: 10.1002/smll.202006891
    In this paper, 2D borophene is synthesized through a liquid-phase exfoliation. The morphology and structure of as-prepared borophene are systemically analyzed, and the Z-scan is used to measure the nonlinear optical properties. It is found that the saturable absorber (SA) properties of borophene make it serve as an excellent broadband optical switch, which is strongly used for mode-locking in near- and mid-infrared laser systems. Ultrastable pulses with durations as short as 792 and 693 fs are successfully delivered at the central wavelengths of 1063 and 1560 nm, respectively. Furthermore, stable pulses at a wavelength of 1878 nm are demonstrated from a thulium mode-locked fiber laser based on the same borophene SA. This research reveals a significant potential for borophene used in lasers helping extending the frontiers of photonic technologies.
  20. Fulltext Genetic Modification of Mucor circinelloides for Canthaxanthin Production by Heterologous Expression of β-carotene Ketolase Gene
    Naz T, Yang J, Nosheen S, Sun C, Nazir Y, Mohamed H, et al.
    Front Nutr, 2021;8:756218.
    PMID: 34722614 DOI: 10.3389/fnut.2021.756218
    Canthaxanthin is a reddish-orange xanthophyll with strong antioxidant activity and higher bioavailability than carotenes, primarily used in food, cosmetics, aquaculture, and pharmaceutical industries. The spiking market for natural canthaxanthin promoted researchers toward genetic engineering of heterologous hosts for canthaxanthin production. Mucor circinelloides is a dimorphic fungus that produces β-carotene as the major carotenoid and is considered as a model organism for carotenogenic studies. In this study, canthaxanthin-producing M. circinelloides strain was developed by integrating the codon-optimized β-carotene ketolase gene (bkt) of the Haematococcus pluvialis into the genome of the fungus under the control of strong promoter zrt1. First, a basic plasmid was constructed to disrupt crgA gene, a negative regulator of carotene biosynthesis resulted in substantial β-carotene production, which served as the building block for canthaxanthin by further enzymatic reaction of the ketolase enzyme. The genetically engineered strain produced a significant amount (576 ± 28 μg/g) of canthaxanthin, which is the highest amount reported in Mucor to date. Moreover, the cell dry weight of the recombinant strain was also determined, producing up to more than 9.0 g/L, after 96 h. The mRNA expression level of bkt in the overexpressing strain was analyzed by RT-qPCR, which increased by 5.3-, 4.1-, and 3-folds at 24, 48, and 72 h, respectively, compared with the control strain. The canthaxanthin-producing M. circinelloides strain obtained in this study provided a basis for further improving the biotechnological production of canthaxanthin and suggested a useful approach for the construction of more valuable carotenoids, such as astaxanthin.
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