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1.
Microb Cell Fact ; 23(1): 3, 2024 Jan 03.
Article in English | MEDLINE | ID: mdl-38172890

ABSTRACT

BACKGROUND: Antibiotics biosynthesis is usually regulated by the cluster-situated regulatory gene(s) (CSRG(s)), which directly regulate the genes within the corresponding biosynthetic gene cluster (BGC). Previously, we have demonstrated that LmbU functions as a cluster-situated regulator (CSR) of lincomycin. And it has been found that LmbU regulates twenty non-lmb genes through comparative transcriptomic analysis. However, the regulatory mode of CSRs' targets outside the BGC remains unknown. RESULTS: We screened the targets of LmbU in the whole genome of Streptomyces lincolnensis and found fourteen candidate targets, among which, eight targets can bind to LmbU by electrophoretic mobility shift assays (EMSA). Reporter assays in vivo revealed that LmbU repressed the transcription of SLINC_0469 and SLINC_1037 while activating the transcription of SLINC_8097. In addition, disruptions of SLINC_0469, SLINC_1037, and SLINC_8097 promoted the production of lincomycin, and qRT-PCR showed that SLINC_0469, SLINC_1037, and SLINC_8097 inhibited transcription of the lmb genes, indicating that all the three regulators can negatively regulate lincomycin biosynthesis. CONCLUSIONS: LmbU can directly regulate genes outside the lmb cluster, and these genes can affect both lincomycin biosynthesis and the transcription of lmb genes. Our results first erected the cascade regulatory circuit of LmbU and regulators outside lmb cluster, which provides the theoretical basis for the functional research of LmbU family proteins.


Subject(s)
Bacterial Proteins , Streptomyces , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Lincomycin , Streptomyces/genetics , Streptomyces/metabolism , Transcriptome , Gene Expression Regulation, Bacterial , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/metabolism
2.
Appl Microbiol Biotechnol ; 107(9): 2933-2945, 2023 May.
Article in English | MEDLINE | ID: mdl-36930277

ABSTRACT

Lincomycin is a broad-spectrum antibiotic and particularly effective against Gram-positive pathogens. Albeit familiar with the biosynthetic mechanism of lincomycin, we know less about its regulation, limiting the rational design for strain improvement. We therefore analyzed two-component systems (TCSs) in Streptomyces lincolnensis, and selected eight TCS gene(s) to construct their deletion mutants utilizing CRISPR/Cas9 system. Among them, lincomycin yield increased in two strains (Δ3900-3901 and Δ5290-5291) while decreased in other four strains (Δ3415-3416, Δ4153-4154, Δ4985, and Δ7949). Considering the conspicuous effect, SLINC_5291-5290 (AflQ1-Q2) was subsequently studied in detail. Its repression on lincomycin biosynthesis was further proved by gene complementation and overexpression. By binding to a 16-bp palindromic motif, the response regulator AflQ1 inhibits the transcription of its encoding gene and the expression of eight operons inside the lincomycin synthetic cluster (headed by lmbA, lmbJ, lmbK, lmbV, lmbW, lmbU, lmrA, and lmrC), as demonstrated by quantitative RT-PCR and electrophoretic mobility shift assays. Besides, the regulatory genes including bldD, glnR, lcbR1, and ramR are also regulated by the TCS. According to the screening towards nitrogen sources, aspartate affects the regulatory behavior of histidine kinase AflQ2. And in return, AflQ1 accelerates aspartate metabolism via ask-asd, asd2, and thrA. In summary, we acquired six novel regulators related to lincomycin biosynthesis, and elucidated the regulatory mechanism of AflQ1-Q2. This highly conserved TCS is a promising target for the construction of antibiotic high-yield strains. KEY POINTS: • AflQ1-Q2 is a repressor for lincomycin production. • AflQ1 modulates the expression of lincomycin biosynthetic and regulatory genes. • Aspartate affects the behavior of AflQ2, and its metabolism is promoted by AflQ1.


Subject(s)
Aspartic Acid , Bacterial Proteins , Aspartic Acid/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Lincomycin , Anti-Bacterial Agents , Gene Expression Regulation, Bacterial
3.
Biosci Biotechnol Biochem ; 87(7): 786-795, 2023 Jun 23.
Article in English | MEDLINE | ID: mdl-37076767

ABSTRACT

AtrA belongs to the TetR family and has been well characterized for its roles in antibiotic biosynthesis regulation. Here, we identified an AtrA homolog (AtrA-lin) in Streptomyces lincolnensis. Disruption of atrA-lin resulted in reduced lincomycin production, whereas the complement restored the lincomycin production level to that of the wild-type. In addition, atrA-lin disruption did not affect cell growth and morphological differentiation. Furthermore, atrA-lin disruption hindered the transcription of regulatory gene lmbU, structural genes lmbA and lmbW inside the lincomycin biosynthesis gene cluster, and 2 other regulatory genes, adpA and bldA. Completement of atrA-lin restored the transcription of these genes to varying degrees. Notably, we found that AtrA-lin directly binds to the promoter region of lmbU. Collectively, AtrA-lin positively modulated lincomycin production via both pathway-specific and global regulators. This study offers further insights into the functional diversity of AtrA homologs and the mechanism of lincomycin biosynthesis regulation.


Subject(s)
Lincomycin , Streptomyces , Lincomycin/pharmacology , Lincomycin/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Streptomyces/genetics , Streptomyces/metabolism , Gene Expression Regulation, Bacterial , Anti-Bacterial Agents/metabolism
4.
Int J Clin Pract ; 2023: 5521691, 2023.
Article in English | MEDLINE | ID: mdl-38045654

ABSTRACT

Purpose: Severe hemorrhage after percutaneous nephrolithotomy (PCNL) is a rare but alerting event. In this study, we report the factors affecting massive hemorrhage after PCNL, various levels of vascular damage during renal angiography, and the therapeutic effect of superselective renal artery embolization (SRAE). Patients and Methods. A retrospective analysis was performed on the data of 69 patients with postoperative PCNL hemorrhage who underwent SRAE from January 2010 to March 2021. Inclusion criteria for all cases were failure of conservative treatment for severe renal hemorrhage after surgery and then treatment with SRAE. In addition, 98 patients without significant hemorrhage after PCNL were randomly selected as the control group. All clinical data are confirmed by imaging and laboratory examinations. We performed univariate and multivariate analyses to find risk factors of massive hemorrhage and high-grade renal vascular injury after PCNL. Results: A total of 69 patients underwent angiography, 64 of which received SRAE due to positive hemorrhages detected by angiography. Urinary tract infection (OR (95% CI) = 11.214 (2.804∼44.842)), high blood pressure (OR (95% CI) = 5.686 (1.401∼23.083)), and no hydronephrosis (OR (95% CI) = 0.189 (0.049∼0.724)) are the most important factors leading to massive hemorrhage after PCNL. In patients who need SRAE after hemorrhage, high-grade vascular injury (grade III) is related to advanced age and decreased hemoglobin. Conclusion: During the perioperative period of PCNL, patients with a risk of hypertension, urinary tract infection, and no hydronephrosis should be strengthened to monitor their high risk of postoperative hemorrhage. For patients with postoperative hemorrhage, we can use the patient's age and decreased hemoglobin before and after operation for analysis. In this way, individualized assessment can greatly improve the efficiency of SRAE treatment.


Subject(s)
Kidney Calculi , Nephrolithotomy, Percutaneous , Urinary Tract Infections , Vascular System Injuries , Humans , Nephrolithotomy, Percutaneous/adverse effects , Vascular System Injuries/complications , Retrospective Studies , Postoperative Hemorrhage/etiology , Postoperative Hemorrhage/therapy , Urinary Tract Infections/etiology , Hemoglobins , Kidney Calculi/surgery , Treatment Outcome
5.
World J Surg Oncol ; 21(1): 385, 2023 Dec 14.
Article in English | MEDLINE | ID: mdl-38097982

ABSTRACT

BACKGROUND: The outcomes of patients with tumors of the thoracolumbar spine treated with en bloc resection (EBR) using three-dimensional (3D)-printed endoprostheses are underreported. METHODS: We retrospectively evaluated patients with thoracolumbar tumors who underwent surgery at our institution. Logistic regression analysis was performed to identify the potential risk factors for surgical complications. Nomograms to predict complications were constructed and validated. RESULTS: A total of 53 patients with spinal tumors underwent EBR at our hospital; of these, 2 were lost to follow-up, 45 underwent total en bloc spondylectomy, and 6 were treated with sagittal en bloc spondylectomy. The anterior reconstruction materials included a customized 3D-printed artificial vertebral body (AVB) in 10 cases and an off-the-shelf 3D-printed AVB in 41 cases, and prosthesis mismatch occurred in 2 patients reconstructed with the off-the-shelf 3D-printed AVB. The median follow-up period was 21 months (range, 7-57 months). Three patients experienced local recurrence, and 5 patients died at the final follow-up. A total of 50 perioperative complications were encountered in 29 patients, including 25 major and 25 minor complications. Instrumentation failure occurred in 1 patient, and no prosthesis subsidence was observed. Using a combined surgical approach was a dependent predictor of overall complications, while Karnofsky performance status score, lumbar spine lesion, and intraoperative blood loss ≥ 2000 mL were predictors of major complications. Nomograms for the overall and major complications were constructed using these factors, with C-indices of 0.850 and 0.891, respectively. CONCLUSIONS: EBR is essential for the management of thoracolumbar tumors; however, EBR has a steep learning curve and a high complication rate. A 3D-printed AVB is an effective and feasible reconstruction option for patients treated with EBR.


Subject(s)
Spinal Neoplasms , Vertebral Body , Humans , Vertebral Body/pathology , Retrospective Studies , Spinal Neoplasms/surgery , Spinal Neoplasms/pathology , Treatment Outcome , Printing, Three-Dimensional
6.
World J Microbiol Biotechnol ; 39(12): 332, 2023 Oct 06.
Article in English | MEDLINE | ID: mdl-37801155

ABSTRACT

Regulators belonging to the DeoR family are widely distributed among the bacteria. Few studies have reported that DeoR family proteins regulate secondary metabolism of Streptomyces. This study explored the function of DeoR (SLINC_8027) in Streptomyces lincolnensis. Deletion of deoR in NRRL 2936 led to an increase in cell growth. The lincomycin production of the deoR deleted strain ΔdeoR was 3.4-fold higher than that of the wild strain. This trait can be recovered to a certain extent in the deoR complemented strain ΔdeoR::pdeoR. According to qRT-PCR analysis, DeoR inhibited the transcription of all detectable genes in the lincomycin biosynthesis cluster and repressed the expression of glnR, bldD, and SLCG_Lrp, which encode regulators outside the cluster. DeoR also inhibited the transcription of itself, as revealed by the XylE reporter. Furthermore, we demonstrated that DeoR bound directly to the promoter region of deoR, lmbA, lmbC-D, lmbJ-K, lmrA, lmrC, glnR, and SLCG_Lrp, by recognizing the 5'-CGATCR-3' motif. This study found that versatile regulatory factor DeoR negatively regulates lincomycin biosynthesis and cellular growth in S. lincolnensis, which expanded the regulatory network of lincomycin biosynthesis.


Subject(s)
Lincomycin , Streptomyces , Lincomycin/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Streptomyces/genetics , Streptomyces/metabolism , Secondary Metabolism , Gene Expression Regulation, Bacterial
7.
World J Urol ; 40(4): 1035-1041, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35029711

ABSTRACT

PURPOSE: Severe haemorrhage in percutaneous nephrolithotomy (PCNL) is an alarming event, and preventing injury to renal major vessels is a challenge. We evaluated the efficiency of a blunt needle in renal puncture procedures. METHODS: We first retrospectively reviewed the embolization images of post-PCNL patients to analyse the types of arteries injured, which were considered target arteries. Then, either a blunt needle or a conventional needle was used to directly puncture target arteries in ex vivo porcine kidneys and to establish renal access ex vivo and in vivo. The primary outcome was the incidence of target artery injuries, which were observed by digital subtraction angiography, nephroscopy and 3-dimensional endocasts. The secondary outcome was the rate of excreted fluid per access. RESULTS: The segmental and interlobar arteries were the most common types of injured arteries that needed to be embolized after PCNL. When these arteries were punctured directly, blunt needles reduced injury (1/20 vs. 16/20; OR 4.750; 95% CI 1.966-11.478; P < .001) by 76% compared to injuries induced by conventional needles. Moreover, the blunt needle group also had a significantly lower incidence of these arteries' injuries ex vivo due to renal puncture and yielded a lower rate of excreted fluid in ex vivo and in vivo renal puncture procedures. CONCLUSION: A blunt needle for renal puncture can be effective in reducing injury to renal major arteries and the accompanying haemorrhage. We propose the concept of blunt puncture, which may be a promising method for achieving safe renal access in PCNL.


Subject(s)
Kidney Calculi , Nephrostomy, Percutaneous , Animals , Hemorrhage , Humans , Kidney/diagnostic imaging , Kidney/surgery , Kidney Calculi/surgery , Needles , Nephrostomy, Percutaneous/methods , Punctures , Retrospective Studies , Swine
8.
J Appl Microbiol ; 133(2): 400-409, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35384192

ABSTRACT

AIMS: Assessing the role of ramRsl , a gene absent in a lincomycin over-producing strain, in the regulation of morphological development and lincomycin biosynthesis in Streptomyces lincolnensis. METHODS AND RESULTS: The gene ramRsl was deleted from the wild-type strain NRRL 2936 and the ΔramR mutant strain was characterized by a slower growth rate and a delayed morphological differentiation compared to the original strain NRRL 2936. Furthermore, the ΔramR produced 2.6-fold more lincomycin than the original strain, and consistently the level of expression of all lincomycin cluster located genes was enhanced at 48 and 96 h in the ΔramR. Complementation of ΔramR with an intact copy of ramRsl restored all wild-type features, whereas the over-expression of ramRsl led to a reduction of 33% of the lincomycin yield. Furthermore, the level of expression of glnR, bldA and SLCG_2919, three of known lincomycin biosynthesis regulators, was lower in the ΔramR than in the original strain at the early stage of fermentation and we demonstrated, using electrophoretic mobility shift assay and XylE reporter assay, that glnR is a novel direct target of RamR. CONCLUSIONS: Altogether, these results indicated that, beyond promoting the morphological development, RamR regulates negatively lincomycin biosynthesis and positively the expression of the nitrogen regulator GlnR. SIGNIFICANCE AND IMPACT OF THE STUDY: We demonstrated that RamR plays a negative role in the regulation of lincomycin biosynthesis in S. lincolnensis. Interestingly, the deletion of this gene in other antibiotic-producing Streptomyces strains might also increase their antibiotic-producing abilities.


Subject(s)
Gene Expression Regulation, Bacterial , Streptomyces , Anti-Bacterial Agents/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Lincomycin/metabolism , Streptomyces/genetics , Streptomyces/metabolism
9.
BMC Urol ; 22(1): 82, 2022 Jun 06.
Article in English | MEDLINE | ID: mdl-35668522

ABSTRACT

BACKGROUND: Although hepatitis B virus (HBV) is a recognized risk factor for renal diseases, little is known about HBV infection in individuals with upper urinary calculi (UUC). We investigated the relationship between chronic HBV infection and UUC. METHODS: We retrospectively analysed data from 1399 patients who were discharged from the Department of Urology (2017-2018). The diagnosis of UUC was determined using urinary tract ultrasonography or computed tomography, and HBV infection was evaluated by a positive hepatitis B surface antigen (HBsAg) test. Data on patients with and without UUC and HBsAg-positive and HBsAg-negative patients were compared by univariate and multivariate analyses. RESULTS: Data on chronic HBV infection and UUC were available for 1062 patients, including 514 who presented with UUC and 548 who did not. Overall, 5.8% of total patients, 8.0% of UUC patients and 3.8% of non-UUC patients had chronic HBV infection. UUC patients (41/514) had a significantly higher prevalence of HBsAg positivity (OR 2.175; 95% CI 1.267-3.734; P = 0.004) than non-UUC patients (21/548). After stratifying by sex, the relative odds of HBsAg positivity were statistically significant in men (OR 2.156; 95% CI 1.162-4.003; P = 0.015) but not in women (OR 2.947; 95% CI 0.816-10.643; P = 0.099). The incidence of urinary pH > 6 and staghorn stones was significantly higher in HBsAg-positive UUC patients than in HBsAg-negative UUC patients. CONCLUSION: This is the first study to demonstrate that chronic HBV infection is strongly associated with UUC, at least in men. The urinary pH > 6 and staghorn stones were more common in UUC patients with chronic HBV infection.


Subject(s)
Hepatitis B, Chronic , Hepatitis B , Urinary Calculi , Urinary Tract , Female , Hepatitis B/complications , Hepatitis B/epidemiology , Hepatitis B Surface Antigens , Hepatitis B virus , Hepatitis B, Chronic/complications , Hepatitis B, Chronic/epidemiology , Humans , Male , Retrospective Studies , Urinary Calculi/complications , Urinary Calculi/epidemiology
10.
J Basic Microbiol ; 61(9): 772-781, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34313330

ABSTRACT

Lincomycin is an important antimicrobial agent which is widely used in clinical and animal husbandry. The biosynthetic pathway of lincomycin comes to light in the past 10 years, however, the regulatory mechanism is still unclear. In this study, a redox-sensing regulator Rex from Streptomyces lincolnensis (Rexlin ) was identified and characterized to affect cell growth and lincomycin biosynthesis. Disruption of rex resulted in an increase in cell growth, but a decrease in lincomycin production. The results of quantitative real-time polymerase chain reaction showed that Rexlin can promote transcription of the regulatory gene lmbU and the structural genes lmbA, lmbC, lmbJ, lmbV, and lmbW. However, electrophoretic mobility shift assay analysis demonstrated that Rexlin can not bind to the promoter regions of these genes above. Findings in this study broadened our horizons in the regulatory mechanism of lincomycin production and laid a foundation for strain improvement of antibiotic producers.


Subject(s)
Anti-Bacterial Agents/biosynthesis , Biosynthetic Pathways/genetics , Gene Expression Regulation, Bacterial , Lincomycin/biosynthesis , Streptomyces/genetics , Streptomyces/metabolism , Bacterial Proteins/genetics , Multigene Family , Oxidation-Reduction , Transcription Factors/genetics
11.
Zhonghua Nan Ke Xue ; 26(3): 250-253, 2020 Mar.
Article in Zh | MEDLINE | ID: mdl-33346965

ABSTRACT

OBJECTIVE: To find the causes of the failure in the first catheter removal (CR) after transurethral resection of the prostate (TURP) and the related risk factors. METHODS: We collected the clinical data on 285 BPH patients treated by TURP from June 2015 to May 2018. We divided the cases into a successful CR (SCR) and a failed CR (FCR) group and investigated the risk factors for the first CR after TURP by multivariate logistic regression analysis. RESULTS: CR was successfully performed in 246 and failed in 39 of the 285 cases. In the FCR group, post-CR urinary retention occurred in 15 cases immediately after, severe urinary tract irritation in 13, massive gross hematuria in 7 and urinary incontinence in 4 within 1 month. Multivariate logistic regression analysis showed that the independent risk factors for CR failure included IPSS (OR = 5.106, P = 0.013), preoperative urinary tract infection (OR = 3.835, P = 0.041), prostate volume (OR = 4.160, P = 0.011) and catheter compression time (OR = 4.051, P = 0.017). CONCLUSIONS: The common causes of the failure in catheter removal after TURP included early postoperative urinary retention, urinary infection, secondary hematuria and urinary incontinence.


Subject(s)
Catheters , Device Removal/adverse effects , Prostatic Hyperplasia , Transurethral Resection of Prostate , Humans , Male , Prostatic Hyperplasia/surgery , Risk Factors , Transurethral Resection of Prostate/adverse effects , Treatment Outcome
12.
Biosci Biotechnol Biochem ; 83(3): 482-489, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30526412

ABSTRACT

Bagremycin A and bagremycin B isolated from Streptomyces sp. Tü 4128 have activities against Gram-positive bacteria, fungi and also have a weak antitumor activity, which make them have great potential for development of novel antibiotics. Here, we report a draft genome 8,424,112 bp in length of S. sp. Tü 4128 by Illumina Hiseq2000, and identify the bagremycins biosynthetic gene cluster (BGC) by bioinformatics analysis. The putative bagremycins BGC includes 16 open reading frames (ORFs) with the functions of biosynthesis, resistance and regulation. Disruptions of relative genes and HPLC analysis of bagremycins production demonstrated that not all the genes within the BGC are responsible for the biosynthesis of bagremycins. In addition, the biosynthetic pathways of bagremycins are proposed for deeper inquiries into their intriguing biosynthetic mechanism.


Subject(s)
Multigene Family/genetics , Streptomyces/genetics , Streptomyces/metabolism , Aminobenzoates/metabolism , Genomics , Mutation
13.
Biosci Biotechnol Biochem ; 83(11): 2082-2089, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31303144

ABSTRACT

Frigocyclinone is a novel antibiotic with antibacterial and anticancer activities. It is produced by both Antarctica-derived Streptomyces griseus NTK 97 and marine sponge-associated Streptomyces sp. M7_15. Here, we first report the biosynthetic gene cluster of frigocyclinone in the S. griseus NTK 97. The frigocyclinone gene cluster spans a DNA region of 33-kb which consists of 30 open reading frames (ORFs), encoding minimal type II polyketide synthase, aromatase and cyclase, redox tailoring enzymes, sugar biosynthesis-related enzymes, C-glycosyltransferase, a resistance protein, and three regulatory proteins. Based on the bioinformatic analysis, a biosynthetic pathway for frigocyclinone was proposed. Second, to verify the cloned gene cluster, CRISPR-Cpf1 mediated gene disruption was conducted. Mutant with the disruption of beta-ketoacyl synthase encoding gene frig20 fully loses the ability of producing frigocyclinone, while inactivating the glycosyltransferase gene frig1 leads to the production of key intermediate of anti-MRSA anthraquinone tetrangomycin.


Subject(s)
Anthraquinones/metabolism , Multigene Family/genetics , Streptomyces griseus/genetics , Streptomyces griseus/metabolism , Cloning, Molecular , Glycosyltransferases/genetics , Glycosyltransferases/metabolism , Streptomyces griseus/enzymology
14.
J Basic Microbiol ; 59(11): 1125-1133, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31553492

ABSTRACT

The yigP (ubiJ) locus has been shown to be associated with many phenotypic changes in Escherichia coli, while the individual function of its two products, EsrE small RNA and UbiJ protein, is still elusive. In this study, we constructed two single-element mutants, EsrE mutant strain Mut and UbiJ mutant strain Ter, on the basis of the base substitution programs. The variable antibiotics resistance and ubiquinone (UQ, coenzyme Q) yield and the similar cell growth between mutants revealed the division of labor and collaboration of EsrE and UbiJ in JM83. Furthermore, we detected the concentration of intracellular proteins of Mut and Ter by stable isotope-labeled quantitative proteomics. The results demonstrate that both EsrE and UbiJ are involved in the aerobic growth of E. coli, while EsrE preferentially contributes to the amino acid-related pathway, and UbiJ is an indispensable factor in the biosynthesis of UQ. Moreover, we uncovered a potential regulatory circuit of d-cycloserine (DCS) that composed of EsrE, GcvA, and GcvB by proteomic analysis.


Subject(s)
Carrier Proteins/metabolism , Escherichia coli Proteins/metabolism , Escherichia coli/metabolism , RNA, Bacterial/metabolism , RNA, Untranslated/metabolism , Carrier Proteins/genetics , Escherichia coli/genetics , Escherichia coli Proteins/genetics , Mutation , Proteomics , RNA, Bacterial/genetics , RNA, Untranslated/genetics , Ubiquinone/biosynthesis
15.
Molecules ; 24(18)2019 Sep 19.
Article in English | MEDLINE | ID: mdl-31546874

ABSTRACT

The authors report a non-enzymatic electrochemical sensor based on a sliver nanoparticle-decorated carbon nanotube (AgNPs-MWCNT). Highly-dispersed AgNPs were loaded on the MWCNT surface though a simple and facile two-step method. The morphology, components, and the size of the AgNPs-MWCNT nanocomposite were characterized by transmission electron microscopy, X-ray diffraction, and ICP analysis. Benefitting from the synergistic effect between the AgNPs and MWCNT, the AgNPs-MWCNT nanocomposite exhibited high electrocatalytic activity for H2O2; the AgNPs-MWCNT electrochemical sensor was prepared by coating the AgNPs-MWCNT nanocomposite on a glassy carbon electrode, and it showed a fast and sensitive response to H2O2 with a linear range of 1 to 1000 µM. The detection limit was 0.38 µM (S/N = 3). The sensor was applied to detect H2O2 in spiked human blood serum samples with satisfactory results.


Subject(s)
Biosensing Techniques/methods , Electrochemical Techniques/methods , Metal Nanoparticles/chemistry , Nanotubes, Carbon/chemistry , Silver/chemistry , Catalysis , Humans , Hydrogen Peroxide/blood , Metal Nanoparticles/ultrastructure , Nanocomposites/chemistry , Nanocomposites/ultrastructure , Nanotubes, Carbon/ultrastructure , Reference Standards , Reproducibility of Results , X-Ray Diffraction
16.
J Bacteriol ; 200(2)2018 01 15.
Article in English | MEDLINE | ID: mdl-29038257

ABSTRACT

Lincomycin A is a clinically important antimicrobial agent produced by Streptomyces lincolnensis In this study, a new regulator designated LmbU (GenBank accession no. ABX00623.1) was identified and characterized to regulate lincomycin biosynthesis in S. lincolnensis wild-type strain NRRL 2936. Both inactivation and overexpression of lmbU resulted in significant influences on lincomycin production. Transcriptional analysis and in vivo neomycin resistance (Neor) reporter assays demonstrated that LmbU activates expression of the lmbA, lmbC, lmbJ, and lmbW genes and represses expression of the lmbK and lmbU genes. Electrophoretic mobility shift assays (EMSAs) demonstrated that LmbU can bind to the regions upstream of the lmbA and lmbW genes through the consensus and palindromic sequence 5'-CGCCGGCG-3'. However, LmbU cannot bind to the regions upstream of the lmbC, lmbJ, lmbK, and lmbU genes as they lack this motif. These data indicate a complex transcriptional regulatory mechanism of LmbU. LmbU homologues are present in the biosynthetic gene clusters of secondary metabolites of many other actinomycetes. Furthermore, the LmbU homologue from Saccharopolyspora erythraea (GenBank accession no. WP_009944629.1) also binds to the regions upstream of lmbA and lmbW, which suggests widespread activity for this regulator. LmbU homologues have no significant structural similarities to other known cluster-situated regulators (CSRs), which indicates that they belong to a new family of regulatory proteins. In conclusion, the present report identifies LmbU as a novel transcriptional regulator and provides new insights into regulation of lincomycin biosynthesis in S. lincolnensisIMPORTANCE Although lincomycin biosynthesis has been extensively studied, its regulatory mechanism remains elusive. Here, a novel regulator, LmbU, which regulates transcription of its target genes in the lincomycin biosynthetic gene cluster (lmb gene cluster) and therefore promotes lincomycin biosynthesis, was identified in S. lincolnensis strain NRRL 2936. Importantly, we show that this new regulatory element is relatively widespread across diverse actinomycetes species. In addition, our findings provide a new strategy for improvement of yield of lincomycin through manipulation of LmbU, and this approach could also be evaluated in other secondary metabolite gene clusters containing this regulatory protein.


Subject(s)
Gene Expression Regulation, Bacterial , Lincomycin/biosynthesis , Streptomyces/genetics , Streptomyces/metabolism , Transcription Factors/metabolism , Bacterial Proteins/metabolism , Multigene Family , Saccharopolyspora/genetics , Secondary Metabolism , Transcription Factors/genetics
17.
Appl Microbiol Biotechnol ; 102(9): 4101-4115, 2018 May.
Article in English | MEDLINE | ID: mdl-29549449

ABSTRACT

Global regulator BldA, the only tRNA for a rare leucine codon UUA, is best known for its ability to affect morphological differentiation and secondary metabolism in the genus Streptomyces. In this study, we confirmed the regulatory function of the bldA gene (Genbank accession no. EU124663.1) in Streptomyces lincolnensis. Disruption of bldA hinders the sporulation and lincomycin production, that can recur when complemented with a functional bldA gene. Western blotting assays demonstrate that translation of the lmbB2 gene which encodes a L-tyrosine hydroxylase is absolutely dependent on BldA; however, mistranslation of the lmbU gene which encodes a cluster-situated regulator (CSR) is observed in a bldA mutant. Intriguingly, when the preferential cognate codon CTG was used, the expression level of LmbU was not the highest compared to the usage of rare codon TTA or CTA, indicating the rare codon in this position is significant for the regulation of lmbU expression. Moreover, replacement of TTA codons in both genes with another leucin codon in the bldA mutant did not restore lincomycin production. Thus, we believe that the bldA gene regulates lincomycin production via controlling the translation of not only lmbB2 and lmbU, but also the other TTA-containing genes. In conclusion, the present study demonstrated the importance of the bldA gene in morphological differentiation and lincomycin production in S. lincolnensis.


Subject(s)
Bacterial Proteins/metabolism , Gene Expression Regulation, Bacterial/genetics , Lincomycin/biosynthesis , RNA, Transfer, Leu/metabolism , Streptomyces/genetics , Streptomyces/metabolism , RNA, Bacterial/metabolism , Streptomyces/cytology
18.
Int Urol Nephrol ; 56(5): 1585-1593, 2024 May.
Article in English | MEDLINE | ID: mdl-38103147

ABSTRACT

BACKGROUND: Kidney stones account for a high proportion of urological emergencies. The main objective of this paper is to evaluate the predictive ability of five scoring systems for overall stone-free status and postoperative complications after percutaneous nephrolithotomy and retrograde ureteroscopy. MATERIALS AND METHODS: This study retrospectively analysed 312 cases of kidney stone patients between January 2021 and May 2022 at our centre. Multivariate logistic regression as well as ROC curves were applied to determine the ability to evaluate each scale to predict stone-free rates and postoperative complications. RESULTS: 179 patients have undergone PCNL. After multivariate logistic regression, the S.T.O.N.E score and history of ipsilateral renal surgery were predictive of stone-free status, and the predictive power of the S.T.O.N.E score was higher than that of history of ipsilateral renal surgery. Grade 1 complications were considered to be related to Guy's score and grade 2 complications were considered to be related to history of diabetes mellitus. 133 patients have undergone f-URS. After multivariate logistic regression analysis, the modified S-ReSC score, RUSS score, and R.I.R.S score were predictive of stone-free status, with the R.I.R.S score being the strongest predictor. Evidence of grade 2 complications was considered to be related to abnormal renal function. CONCLUSION: For PCNL, the S.T.O.N.E score had the best efficacy in predicting stone-free status, and the Guy's score had the best efficacy in predicting postoperative complications; for f-URS, the R.I.R.S score had the best efficacy in predicting stone-free status, and no scoring system predicted postoperative complications.


Subject(s)
Kidney Calculi , Nephrolithotomy, Percutaneous , Humans , Nephrolithotomy, Percutaneous/adverse effects , Treatment Outcome , Retrospective Studies , Ureteroscopy/adverse effects , Length of Stay , Operative Time , Kidney Calculi/complications , Postoperative Complications/epidemiology , Postoperative Complications/etiology
19.
Urolithiasis ; 52(1): 35, 2024 Feb 20.
Article in English | MEDLINE | ID: mdl-38376588

ABSTRACT

Rhizoma Polygonati (RP) is the dried rhizome of the liliaceous plant. It has anti-inflammatory and anti-apoptosis effects. But its role in kidney stones has not been studied. The purpose of this study was to verify the effect of RP in the treatment of nephrolithiasis through network pharmacological analysis and in vivo experiments. The active compounds and protein targets of RP, as well as the potential targets of the nephrolithiasis were searched from the database. The protein-protein interaction (PPI) network diagram and the drug-compounds-targets-disease network were constructed. The enrichment analysis was performed by Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG). Subsequently, the effect of RP on the prevention and treatment of nephrolithiasis was experimentally validated in vivo. Animal experiments showed that RP ameliorates renal function and reduced crystal deposition in a mouse model. It may act through anti-inflammation and anti-apoptosis. Our study showed that RP could prevent and treat nephrolithiasis by inhibiting apoptosis and inflammation, which provided a new efficacy and clinical application for RP.


Subject(s)
Kidney Calculi , Network Pharmacology , Animals , Mice , Rhizome , Kidney Calculi/drug therapy , Apoptosis , Databases, Factual
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