Glycine suppresses kidney calcium oxalate crystal depositions via regulating urinary excretions of oxalate and citrate.

An abnormal urine composition is a key reason for kidney stone formation, but little is known about the roles of small metabolites in the urine during kidney stone formation. Here, we found urine glycine in patients with kidney calcium oxalate (CaOx) stone was significantly lower than that in healthy people via 1 H NMR spectra detection, and investigated the role and underlying mechanism of glycine in the regulation of CaOx stone formation. Our results showed that glycine could significantly attenuate ethylene glycol-induced CaOx crystal depositions in rat kidney via decreasing urine oxalate and increasing urine citrate. Mechanism studies revealed that glycine could decrease urine oxalate through downregulating Slc26a6 expression, whereas increase urine citrate via inhibiting Nadc1 expression. Moreover, glycine decreased the protein expression of both Slc26a6 and Nadc1 via increasing the expression of miRNA-411-3p, which directly bound to the 3'-untranslated regions of Slc26a6 and Nadc1 messenger RNAs, in vitro and in vivo. Together, our results revealed a novel role of glycine in the regulation of kidney CaOx crystal formation and provided a potential target for the treatment of kidney CaOx stone.

Identifying the novel key genes in renal cell carcinoma by bioinformatics analysis and cell experiments.

BACKGROUND: Although major driver gene have been identified, the complex molecular heterogeneity of renal cell cancer (RCC) remains unclear. Therefore, more relevant genes need to be identified to explain the pathogenesis of renal cancer. METHODS: Microarray datasets GSE781, GSE6344, GSE53000 and GSE68417 were downloaded from Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) were identified by employing GEO2R tool, and function enrichment analyses were performed by using DAVID. The protein-protein interaction network (PPI) was constructed and the module analysis was performed using STRING and Cytoscape. Survival analysis was performed using GEPIA. Differential expression was verified in Oncomine. Cell experiments (cell viability assays, transwell migration and invasion assays, wound healing assay, flow cytometry) were utilized to verify the roles of the hub genes on the proliferation of kidney cancer cells (A498 and OSRC-2 cell lines). RESULTS: A total of 215 DEGs were identified from four datasets. Six hub gene (SUCLG1, PCK2, GLDC, SLC12A1, ATP1A1, PDHA1) were identified and the overall survival time of patients with RCC were significantly shorter. The expression levels of these six genes were significantly decreased in six RCC cell lines(A498, OSRC-2, 786- O, Caki-1, ACHN, 769-P) compared to 293t cell line. The expression level of both mRNA and protein of these genes were downregulated in RCC samples compared to those in paracancerous normal tissues. Cell viability assays showed that overexpressions of SUCLG1, PCK2, GLDC significantly decreased proliferation of RCC. Transwell migration, invasion, wound healing assay showed overexpression of three genes(SUCLG1, PCK2, GLDC) significantly inhibited the migration, invasion of RCC. Flow cytometry analysis showed that overexpression of three genes(SUCLG1, PCK2, GLDC) induced G1/S/G2 phase arrest of RCC cells. CONCLUSION: Based on our current findings, it is concluded that SUCLG1, PCK2, GLDC may serve as a potential prognostic marker of RCC.

Percutaneous nephrolithotomy versus flexible ureteroscopic lithotripsy in the treatment of upper urinary tract stones: a meta-analysis comparing clinical efficacy and safety.

BACKGROUND: Upper urinary tract stones is the most common diseases in urology. Percutaneous nephrolithotomy (PCNL) and ureteroscopic lithotripsy (fURL) are common treatment, but both their efficacy and safety are controversial. Thus we aim to evaluate the efficacy and safety of PCNL and fURL in the treatment of upper urinary tract stones, providing a reference for clinical work. METHODS: PubMed, Web of Science, Embase and CNKI were searched through Apr. 1, 2019 to identify eligible studies. Data were analyzed by using RevMan 5.3 and Stata 12.0 software. Pooled relative risks (RRs) or weighted mean difference (WMD) with 95% confidence intervals (CIs) were calculated using fixed or random effects methods. Publication bias and sensitivity analysis were performed. RESULTS: Four randomized controlled trials (RCTs), fifteen cohort studies involving 1822 patients were included. Stone-free rate of PCNL was significantly high than that of fURL (RR: 1.07; 95% CI: 1.03, 1.12; P = 0.0004). The decline of hemoglobin in PCNL was significantly high than that of fURL (WMD: 1.07; 95% CI: 0.54, 1.61; P < 0.0001). The number of blood transfusion was significantly greater in the PCNL compared to the fURL (RR: 5.04; 95% CI: 1.78, 14.24; P = 0.002). The incidence of postoperative bleeding or hematuria showed greater significantly difference in the PCNL compared to the fURL (RR: 2.72; 95% CI: 1.55, 4.75; P = 0.0005). Operation time, fever, infection, perforation, requiring drug analgesia was not significantly different between two surgical procedures. CONCLUSIONS: In the treatment of upper urinary tract stones, the stones clearance rate of PCNL is higher than fURL, and the safety of fURL is higher than PCNL.

Impact of dyslipidemia on 24-h urine composition in adults without urolithiasis.

PURPOSES: To evaluate the influence of dyslipidemia on 24-h urine composition in adults who were non-stone formers (NF). METHODS: Samples for 24-h urine composition were analyzed from 584 NF adults without urolithiasis in a national six-city-based epidemiologic study. The samples were divided into groups based on total cholesterol (TC), triglycerides (TG), high-density lipoprotein (HDL), and low-density lipoprotein (LDL). The groups were compared based on demographic data and each component of 24-h urinalysis. RESULTS: The numbers of participants in high TG, high TC, high LDL, and low HDL were 106, 175, 147, and 59, respectively. The high TG group had increased urinary excretions of oxalate [mean difference (MD) = 0.032 mmol, 95% confidence interval (CI): 0.000-0.065] and potassium (MD = 4.298 mmol, 95%CI: 0.182-8.414). Increased urinary excretion of calcium (MD = 0.531 mmol, 95%CI: 0.061-1.001), sodium (MD = 41.561 mmol, 95%CI: 9.179-73.942), and chloride (MD = 45.209 mmol, 95%CI: 12.118-78.299) were found in the high TC group. Interestingly, the high LDL group had a decreased urinary excretion of calcium (MD = - 0.573 mmol, 95%CI: -1.048 to - 0.097), oxalate (MD = - 0.038 mmol, 95%CI: -0.07 to - 0.006), sodium (MD = - 53.285 mmol, 95%CI: -85.823 to - 20.748), and chloride (MD = - 55.809 mmol, 95%CI: -89.035 to - 22.583). Increased urinary excretions of citrate (MD = 0.455 mmol, 95%CI: 0.076-0.835) and magnesium (MD = 0.697 mmol, 95%CI: 0.244-1.149) were found in the low HDL group. CONCLUSIONS: The present study first investigated the effects of dyslipidemia on 24-h urinalysis in NF adults. Of note, high LDL and low HDL were found to be adversely related to kidney stone formation. However, people with high TG and high TC should be cautious of getting kidney stones.

[Updated evaluation and intervention of adolescent varicocele].

Some physiological and ethical problems make it difficult to obtain semen samples from adolescents with varicocele (VC) and to directly evaluate their fertility. Therefore we can only rely on indirect methods to assess the influence of VC on the future fertility of the adolescent patients. Most of the VC adolescents may have normal semen parameters in the adulthood. Thus whether and when to intervene in adolescent VC remain a controversy in andrology. Physical examination is the most common method for screening adolescent VC and ultrasonography is very effective for its diagnosis and evaluation. Other important diagnostic indicators include the widely accepted testicular atrophy index, recently proposed peak retrograde venous flow, total testis volume, and scrotal temperature. Based on the latest literature, this review offers some proposals for the evaluation and intervention of adolescent VC.

Molecular chaperones (TrxA, SUMO, Intein, and GST) mediating expression, purification, and antimicrobial activity assays of plectasin in Escherichia coli.

Plectasin (PS) is the first defensin to be isolated from a fungus, the saprophytic ascomycete Pseudoplectania nigrella, and active against Streptococcus pneumoniae and S. aureus, including antibiotic-resistant pathogens. To establish a bacterium-based production system, we compared the efficiency of four molecular chaperones and corresponding cleavage to the expression and purification of plectasin. The results showed that the yield of plectasin combined with thioredoxin A (TrxA) and small ubiquitin-related modifier (SUMO) was at a higher level (0.0356 and 0.0358 g L(-1), respectively) than that with intein (0.0238 g L(-1)) and glutathione-S-transferase (GST) (0.0243 g L(-1)). TrxA-plectasin, SUMO-plectasin, and 2-plectasin were cleaved at the correct site and purified, but their considerable amount was not cleaved and remained as a fusion peptide. The antimicrobial activity of plectasin cleaved from SUMO--plectasin against methicillin-resistant Staphylococcus aureus (MRSA), penicillin-resistant S. pneumoniae (PRSP), and vancomycin-resistant enterococci (VRE)--was stronger than ampicillin (Amp) for the same amount of substance (P ≤ 0.05). This is the first study to complete and compare the effect of different molecular chaperones and corresponding cleavage with the expression and purification of plectasin in the Escherichia coli expression system, which laid the foundation for future research and may develop the application and production of plectasin.

MRI-Based Nomogram of Prostate Maximum Sectional Area and Its Zone Area for Prediction of Prostate Cancer.

OBJECTIVE: To reduce unnecessary prostate biopsies, we designed a magnetic resonance imaging (MRI)-based nomogram prediction model of prostate maximum sectional area (PA) and investigated its zone area for diagnosing prostate cancer (PCa). METHODS: MRI was administered to 691 consecutive patients before prostate biopsies from January 2012 to January 2020. PA, central gland sectional area (CGA), and peripheral zone sectional area (PZA) were measured on axial T2-weighted prostate MRI. Multivariate logistic regression analysis and area under the receiver operating characteristic (ROC) curve were performed to evaluate and integrate the predictors of PCa. Based on multivariate logistic regression coefficients after excluding combinations of collinear variables, three models and nomograms were generated and intercompared by Delong test, calibration curve, and decision curve analysis (DCA). RESULTS: The positive rate of PCa was 46.74% (323/691). Multivariate analysis revealed that age, PSA, MRI, transCGA, coroPZA, transPA, and transPAI (transverse PZA-to-CGA ratio) were independent predictors of PCa. Compared with no PCa patients, transCGA (AUC = 0.801) was significantly lower and transPAI (AUC = 0.749) was significantly higher in PCa patients. Both of them have a significantly higher AUC than PSA (AUC = 0.714) and PV (AUC = 0.725). Our best predictive model included the factors age, PSA, MRI, transCGA, and coroPZA with the AUC of 0.918 for predicting PCa status. Based on this predictive model, a novel nomogram for predicting PCa was conducted and internally validated (C-index = 0.913). CONCLUSIONS: We found the potential clinical utility of transCGA and transPAI in predicting PCa. Then, we firstly built the nomogram based on PA and its zone area to evaluate its diagnostic efficacy for PCa, which could reduce unnecessary prostate biopsies.

Sexual Dysfunction in Patients With Urinary Bladder Stones but no Bladder Outlet Obstruction.

Objective: To explore the correlates of sexual dysfunction and lower urinary tract symptoms (LUTS) in male patients with urinary bladder stones and to determine the effect of stone extraction on recovery of sexual function. Materials and Methods: A total of 87 male patients with primary bladder stones were studied from January 2015 to May 2016. All patients underwent pneumatic lithotripsy for bladder stones. Sexual dysfunction was assessed based on sexual function assessment scales. The relationship of bladder stones with sexual dysfunction or LUTS was assessed using a two-sample t-test. Postoperative improvement of sexual function was assessed by repeated measures Analysis of Variance (ANOVA). Results: Forty-one patients had primary bladder stones and 46 had secondary stones from the kidneys. Eighty-three of 87 patients (95%) had sexual dysfunction; 79 patients (91%) had both sexual dysfunction and LUTS. There was a significant association between bladder stones and sexual dysfunction, between sexual dysfunction and LUTS, and between bladder stone and LUTS (p < 0.05). There was no significant association between the course of illness, size and number of bladder stones, or urinary tract infection with sexual function (p > 0.05). In addition, among 83 patients with both bladder stone and sexual dysfunction, 61 patients (73%) had benign prostatic hyperplasia (BPH) and 22 patients (27%) had no BPH. On postoperative evaluation at 3 months, sexual dysfunction scores were significantly improved in 77 patients (88.5%) Conclusion: Patients with bladder stones have a high incidence of sexual dysfunction, particularly those with co-existing LUTS and BPH. About 1/3 patients without BPH had sexual dysfunction and surgical removal of bladder stones significantly improved sexual function and LUTS.

Identification of Prostate Cancer-Related Circular RNA Through Bioinformatics Analysis.

BACKGROUND: Prostate cancer (PCa) is one of the most common malignant tumors worldwide. Accumulating evidence has suggested that circular RNAs (circRNAs) are involved in the development and progression of various cancers, and they show great potential as novel biomarkers. However, the underlying mechanisms and specific functions of most circRNAs in PCa remain unknown. Here, we aimed to identify circRNAs with potential roles in PCa from the PCa expression profile. METHODS: We used data downloaded from the Gene Expression Omnibus to identify circRNAs that were differentially expressed between PCa samples and adjacent non-tumor samples. Relative expression levels of identified circRNAs were validated by quantitative real-time PCR. Micro (mi)RNA response elements were predicted by the CircInteractome database, and miRNA target genes were predicted by miRDB, miRTarBase, and TargetScan databases. Gene ontology (GO) enrichment analysis and pathway analysis revealed the potential biological and functional roles of these target genes. A circRNA-miRNA-mRNA interaction network was constructed by Cytoscape. The interaction between circRNAs and miRNAs in PCa was thoroughly reviewed in the PubMed. Finally, the mRNA expression of these genes was validated by the Cancer Genome Atlas (TCGA) and Gene Expression Profiling Interactive Analysis (GEPIA) databases. The expression of proteins encoded by these genes was further validated by the Human protein Atlas (HPA) database. RESULTS: A total of 60 circRNAs that were differentially expressed between PCa and healthy samples were screened, of which 15 were annotated. Three circRNAs (hsa_circ_0024353, hsa_circ_0085494, hsa_circ_0031408) certified the criteria were studied. The results of quantitative real-time PCR demonstrated that the expression of hsa_circ_0024353 was significantly downregulated in PC-3 cells when compared with RWPE-1 cells, while the expression of hsa_circ_0031408 and hsa_circ_0085494 was significantly upregulated in PC-3 cells when compared with RWPE-1 cells. GO and Kyoto Encyclopedia of Genes and Genomes analyses found that target genes were mainly enriched in metabolic processes and pathways involving phosphoinositide 3-kinase-Akt signaling, hypoxia-inducible factor-1 signaling, p53 signaling, and the cell cycle. A total of 11 miRNA target genes showing differential expression between PCa and healthy samples were selected, and their mRNA and protein expression were validated by GEPIA and HPA databases, respectively. Of these, PDE7B, DMRT2, and TGFBR3 were identified as potentially playing a role in PCa progression. Finally, three circRNA-miRNA-mRNA interaction axes were predicted by bioinformatics: hsa_circ_0024353-hsa-miR-940-PDE7B, hsa_circ_0024353-hsa-miR-1253-DMRT2, and hsa_circ_0085494-hsa-miR-330-3p-TGFBR3. CONCLUSION: This study identified three circRNA-miRNA-mRNA interaction axes that might provide novel insights into the potential mechanisms underlying PCa development.

Identifying the key genes and microRNAs in prostate cancer bone metastasis by bioinformatics analysis.

Prostate adenocarcinoma (PCa) is the most common cause of death due to malignancy among men, and bone metastasis is the leading cause of mortality in patients with PCa. Therefore, identifying the causes and molecular mechanism of bone metastasis is important for early detection, diagnosis and personalized therapy. In this study, we systematically analyzed molecular correlates of bone metastasis by bioinformatics analysis. A total of 12 differentially expressed microRNAs (miRNAs) and 102 differentially expressed genes were identified. Five miRNAs had prognostic significance in biochemical recurrence-free survival (miR-636, miR-491-5p, miR-199b-5p, miR-199b-3p, miR-28-3p). The differentially expressed genes were significantly enriched in extracellular matrix, cell-substrate adhesion, collagen and integrin. Seven hub genes (VCAN, COL3A1, COL1A1, APOE, COL1A2, SDC1, THY1) with worse biochemical recurrence-free survival and one hub gene (MMP9) with worse overall survival were detected. miR-636, a novel oncogene, was found to be up-regulated in bone metastatic PCa tissues and also predominately up-regulated in human PCa cell lines. miR-636 promoted cellular invasion and migration, and may promote bone metastasis via targeting MBNL2, TNS1 and STAB1. In conclusion, we have successfully defined molecular signatures of bone metastasis in PCa.

Identification of key genes and pathways in castrate-resistant prostate cancer by integrated bioinformatics analysis.

OBJECTIVE: To identify hub genes and pathways involved in castrate-resistant prostate cancer (CRPC). METHODS: The gene expression profiles of GSE70768 were downloaded from Gene Expression Omnibus (GEO) datasets. A total of 13 CRPC samples and 110 tumor samples were identified. The differentially expressed genes (DEGs) were identified, and the gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analysis was performed. Protein-protein interaction (PPI) network module analysis was constructed and performed in Cytoscape software. Weighted correlation network analysis (WGCNA) was conducted to determine hub genes involved in the development and progression of CRPC. The gene expression profiles of GSE80609 were used for validation. RESULTS: A total of 1738 DEGs were identified, consisting of 962 significantly down-regulated DEGs and 776 significantly upregulated DEGs for the subsequent analysis. GO term enrichment analysis suggested that DEGs were mainly enriched in the extracellular matrix organization, extracellular exosome, extracellular matrix, and extracellular space. KEGG pathway analysis found DEGs significantly enriched in the focal adhesion pathway. PPI network demonstrated that the top 10 hub genes were ALB, ACACB, KLK3, CDH1, IL10, ALDH1A3, KLK2, ALDH3B2, HBA1, COL1A1. Also, WGCNA identified the top 5 hub genes in the turquoise module, including MBD4, BLZF1, PIP5K2B, ZNF486, LRRC37B2. Plus, the Venn diagram demonstrated that HBA1 was the key gene in both GSE70768 and GSE80609 datasets. CONCLUSIONS: These newly identified genes and pathways could help urologists understand the differences in the mechanism between CRPC and PCa. Besides, it might be promising targets for the treatment of CRPC.

The clinicopathological and prognostic value of PD-L1 in urothelial carcinoma: a meta-analysis.

The prognostic value of programed death-ligand 1 (PD-L1) in urothelial carcinoma (UC) has been assessed in previous studies, while the results remain controversial and heterogeneous. Therefore, we performed this meta-analysis to explore the prognostic effect of PD-L1 in patients with UC. PubMed, Embase and Web of Science were searched to identify the studies. Hazard ratios (HR) with 95% confidence interval (95% CI) and clinicopathological factors were extracted from included studies. A total of 1819 patients with UC from 11 published studies were incorporated. The results of meta-analysis showed that positive PD-L1 expression was significantly associated with poorer overall survival (OS) (HR 1.59, 95% CI 1.05-2.40) and disease-free survival (DFS) (HR 1.83, 95% CI 1.03-3.25), but not recurrence-free survival. Moreover, in the subgroup analysis, significant associations between PD-L1 expression and OS or DFS were found in bladder UC, the cutoff value of positive expression of PD-L1 ≥ 5% and the expression of PD-L1 on the tumor cell membrane. Interestingly, positive PD-L1 expression was correlated with poorer pathological T stage (OR 2.03, 95% CI 1.46-2.82). Our meta-analysis implies that PD-L1 might be a valuable biomarker of poor prognosis for UC, especially bladder UC, although further large-scale and well-designed studies are warranted to verify the prognostic value of PD-L1 for UC.

Association between vasectomy and risk of testicular cancer: A systematic review and meta-analysis.

OBJECTIVES: A number of researchers have reported that vasectomy is a risk factor for testicular cancer. However, this conclusion is inconsistent with a number of other published articles. Hence, we conducted this meta-analysis to assess whether vasectomy increases the risk of testicular cancer. MATERIALS AND METHODS: We identified all related studies by searching the PubMed, Embase, and Cochrane Library database from January 01, 1980 to June 01, 2017. The Newcastle-Ottawa Scale (NOS) checklist was used to assess all included non-randomized studies. Summarized odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the difference in outcomes between case and control groups. Subgroup analyses were performed according to the study design and country. RESULTS: A total of eight studies (2176 testicular cancer patients) were included in this systematic review and meta-analysis. Six articles were case-control studies, and two were cohort studies. The pooled estimate of the OR was 1.10 (95% CI: 0.93-1.30) based on the eight studies in a fixed effects model. Two subgroup analyses were performed according to the study design and country. The results were consistent with the overall findings. Publication bias was detected by Begg's test and Egger's test and p values > 0.05, respectively. CONCLUSIONS: Our meta-analysis suggested that there was no association between vasectomy and the development of testicular cancer. More high-quality studies are warranted to further explore the association between vasectomy and risk of testicular cancer.

The prognostic value of HOXA13 in solid tumors: A meta-analysis.

PURPOSE: The prognostic value of homeobox (HOX) A13 (HOXA13) in cancer remains uncertain due to limitations of sample size and discrete outcome in previous studies. We performed this meta-analysis to explore the prognostic effect of HOXA13 in patients with solid tumors. METHODS: PubMed, Embase, and Web of Science were searched to identify eligible studies. Hazard ratios (HR) with 95% confidence interval (95%CI) and clinicopathological factors were extracted. Subgroup analysis according to cancer type, sample size and analysis method were also performed. RESULTS: A total of 844 patients with solid tumor from 9 eligible studies were incorporated in the meta-analysis. We found that high HOXA13 expression level was significantly associated with poor overall survival (OS) in human cancer (HR = 2.23; 95%CI: 1.74-2.85), and significantly related to poorer histological grade (odds ratio (OR) = 2.03, 95%CI: 1.40-2.96), positive lymph node metastasis (OR = 1.96, 95%CI: 1.26-3.02) and more advanced tumor-node-metastasis (TNM) stage (OR = 3.92, 95%CI: 2.46-6.22). CONCLUSION: Our meta-analysis suggests that HOXA13 might be a valuable biomarker of poor prognosis and a potential therapeutic target for human solid tumors.

Phosphoglycerate mutase 1 knockdown inhibits prostate cancer cell growth, migration, and invasion.

Phosphoglycerate mutase 1 (PGAM1) is upregulated in many cancer types and involved in cell proliferation, migration, invasion, and apoptosis. However, the relationship between PGAM1 and prostate cancer is poorly understood. The present study investigated the changes in PGAM1 expression in prostate cancer tissues compared with normal prostate tissues and examined the cellular function of PGAM1 and its relationship with clinicopathological variables. Immunohistochemistry and Western blotting revealed that PGAM1 expression was upregulated in prostate cancer tissues and cell lines. PGAM1 expression was associated with Gleason score (P = 0.01) and T-stage (P = 0.009). Knockdown of PGAM1 by siRNA in PC-3 and 22Rv1 prostate cancer cell lines inhibited cell proliferation, migration, and invasion and enhanced cancer cell apoptosis. In a nude mouse xenograft model, PGAM1 knockdown markedly suppressed tumor growth. Deletion of PGAM1 resulted in decreased expression of Bcl-2, enhanced expression of Bax, caspases-3 and inhibition of MMP-2 and MMP-9 expression. Our results indicate that PGAM1 may play an important role in prostate cancer progression and aggressiveness, and that it might be a valuable marker of poor prognosis and a potential therapeutic target for prostate cancer.

The Stability, and Efficacy Against Penicillin-Resistant Enterococcus faecium, of the Plectasin Peptide Efficiently Produced by Escherichia coli.

Plectasin, the first defensin extracted from a fungus (the saprophytic ascomycete Pseudoplectania nigrella), is attractive as a prospective antimicrobial agent. The purpose of this study was to establish a bacterium-based production system and evaluate the antimicrobial activity of the resulting plectasin. A gene encoding plectasin, with the codon preference of Escherichia coli, was optimized based on its amino acid sequence, synthesized using gene-splicing with overlap extension PCR, and inserted into the expression vector pGEX-4T-1. The fusion protein was expressed in the soluble fraction of E. coli and purified using glutathione Stransferase affinity chromatography. Plectasin was cleaved from the fusion protein with thrombin and purified by ultrafiltration. The purified plectasin showed strong, concentration-dependent antimicrobial activity against gram-positive bacteria, including antibiotic-resistant bacteria, especially penicillin-resistant Enterococcus faecium. This antimicrobial activity was equal to chemically synthesized plectasin and was maintained over a wide range of pH and temperatures. This soluble recombinant expression system in E. coli is effective for producing plectasin at a relatively lower cost, and higher purity and efficiency than prior systems, and might provide a foundation for developing a large-scale production system. Overall, plectasin shows potential as a novel, high-performance, and safe antibiotic for the treatment of refractory diseases caused by drug-resistant bacterial strains.