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1.
Mol Immunol ; 149: 165-173, 2022 09.
Article in English | MEDLINE | ID: mdl-35905592

ABSTRACT

Cutaneous leishmaniasis (CL) is a neglected tropical disease with severe morbidity and socioeconomic sequelae. A better understanding of underlying immune mechanisms that lead to different clinical outcomes of CL could inform the rational design of intervention measures. While transcriptomic analyses of CL lesions were recently reported by us and others, there is a dearth of information on the expression of immune-related genes in the blood of CL patients. Herein, we investigated immune-related gene expression in whole blood samples collected from individuals with different clinical stages of CL along with healthy volunteers in an endemic CL region where Leishmania (L.) tropica is prevalent. Study participants were categorized into asymptomatic (LST+) and healthy uninfected (LST-) groups based on their leishmanin skin test (LST). Whole blood PAXgene samples were collected from volunteers, who had healed CL lesions, and patients with active L. tropica cutaneous lesions. Quality RNA extracted from 57 blood samples were subjected to Dual-color reverse-transcription multiplex ligation-dependent probe amplification (dcRT-MLPA) assay for profiling 144 immune-related genes. Results show significant changes in the expression of genes involved in interferon signaling pathway in the blood of active CL patients, asymptomatics and healed individuals. Nonetheless, distinct profiles for several immune-related genes were identified in the healed, the asymptomatic, and the CL patients compared to the healthy controls. Among others, IFI16 and CCL11 were found as immune transcript signatures for the healed and the asymptomatic individuals, respectively. These results warrant further exploration to pinpoint novel blood biomarkers for different clinical stages of CL.


Subject(s)
Leishmania , Leishmaniasis, Cutaneous , Gene Expression Profiling , Humans , Leishmaniasis, Cutaneous/diagnosis , Leishmaniasis, Cutaneous/genetics , Skin Tests
2.
Microb Cell Fact ; 20(1): 219, 2021 Dec 04.
Article in English | MEDLINE | ID: mdl-34863163

ABSTRACT

BACKGROUND: Several studies have shown that probiotics have beneficial effects on weight control and metabolic health. In addition to probiotics, recent studies have investigated the effects of paraprobiotics and postbiotics. Therefore, we evaluated the preventive effects of live and pasteurized Akkermansia muciniphila MucT (A. muciniphila) and its extracellular vesicles (EVs) on HFD-induced obesity. RESULTS: The results showed that body weight, metabolic tissues weight, food consumption, and plasma metabolic parameters were increased in the HFD group, whereas A. muciniphila preventive treatments inhibited these HFD. The effects of pasteurized A. muciniphila and its extracellular vesicles were more noticeable than its active form. The HFD led to an increase in the colonic, adipose tissue, and liver inflammations and increased the expression of genes involved in lipid metabolism and homeostasis. Nevertheless, these effects were inhibited in mice that were administered A. muciniphila and its EVs. The assessment of the gut microbiota revealed significant differences in the microbiota composition after feeding with HFD. However, all treatments restored the alterations in some bacterial genera and closely resemble the control group. Also, the correlation analysis indicated that some gut microbiota might be associated with obesity-related indices. CONCLUSIONS: Pasteurized A. muciniphila and its EVs, as paraprobiotic and postbiotic agents, were found to play a key role in the regulation of metabolic functions to prevent obesity, probably by affecting the gut-adipose-liver axis.


Subject(s)
Adipose Tissue/metabolism , Extracellular Vesicles , Obesity/prevention & control , Probiotics/administration & dosage , Akkermansia/cytology , Akkermansia/physiology , Animals , Homeostasis/genetics , Lipid Metabolism/genetics , Male , Mice , Mice, Inbred C57BL , Pasteurization
3.
Iran J Allergy Asthma Immunol ; 20(5): 563-573, 2021 Sep 28.
Article in English | MEDLINE | ID: mdl-34664815

ABSTRACT

Ankylosing spondylitis (AS) is a systemic inflammatory disorder of joints and entheses. Recent studies have reported an increased prevalence of dementia in AS patients. However, data for exploring the association between dementia and AS remain uncertain. In this study, enriched pathways and differentially expressed genes (DEGs) were identified in whole blood transcription data of AS patients obtained from the gene expression omnibus (GEO) database; using gene set enrichment analysis (GSEA) and differential expression analysis. Four pathways, including oxidative phosphorylation, Alzheimer's, Parkinson's, and Huntington's diseases were significantly enriched in AS patients compared to the controls. We identified 22 common genes among the pathways that showed an increasing trend in AS compared to the controls. Five of them including COX7B, NDUFB3, ATP5PF, UQCRB, and NDUFS4 were the most significant genes which were selected for gene expression analysis; using real-time PCR on RNA contents of peripheral blood mononuclear cells (PBMCs) of AS patients and controls (20 samples from each group). The gene expression analysis indicated considerable overexpression of COX7B (p<0.0001) and ATP5J (p=0.0001) genes in AS patients group in comparison to the control samples. The role of oxidative phosphorylation has previously been established in dementia pathogenesis. Given that AS patients have also a remarkably higher prevalence of dementia than the their healthy counterparts, hence our results may propose that the common pathway of oxidative phosphorylation can be regarded as a possible shared contributing factor in the etiopathogenesis of AS and dementia.


Subject(s)
Metabolic Networks and Pathways , Oxidative Phosphorylation , Spondylitis, Ankylosing/genetics , Spondylitis, Ankylosing/metabolism , Transcriptome , Biomarkers , Computational Biology/methods , Databases, Genetic , Disease Susceptibility , Gene Expression Profiling , Humans , Neurodegenerative Diseases/etiology , Neurodegenerative Diseases/metabolism , Neurodegenerative Diseases/pathology , Spondylitis, Ankylosing/pathology
4.
Sci Rep ; 11(1): 17898, 2021 09 09.
Article in English | MEDLINE | ID: mdl-34504116

ABSTRACT

Recently, Akkermansia muciniphila an anaerobic member of the gut microbiota, has been proposed as a next-generation probiotic. The aim of this study was evaluation of the effect of alive and pasteurized A. muciniphila on health status, intestinal integrity, immune response, lipid metabolism, and gut microbial composition in normal-diet fed mice as well as direct effects of the bacterium on Caco-2 cell line. A total of 30 mice were distributed into three different groups, control, alive, and pasteurized A. muciniphila-treated group. After acclimation, control and treatment groups were administrated with PBS and 109 CFU/200µL of bacterial suspension for 5 weeks, respectively. Besides, Caco-2 separately exposed to alive, pasteurized A. muciniphila and PBS for 24 h. The results showed that administration of A. muciniphila leads to reduction in body, liver, and white adipose weight. Histology data revealed both treatments had no adverse effects in colon, liver, and adipose tissues as well as induced better gut structure. Moreover, biochemical parameters and inflammatory biomarkers in plasma demonstrated that pasteurized A. muciniphila had more pronounce effect. Furthermore, alive A. muciniphia had better effects on the modulation of gene expression related to fatty acid synthesis, energy homeostasis, and immune response in the liver; meanwhile, these effects in the adipose was more in the pasteurized A. muciniphila administration. More importantly, the improvement of gut health by enhancing strengthen intestinal integrity and maintaining immune homeostasis was seen in both treatments; notably, pasteurized A. muciniphila had more effective. Similarly, treatment with the pasteurized form more effectively upregulated tight junction and regulated immune response-related genes in Caco-2 cell line. Both treatments triggered the improvement of microbiota communities, particularly the alive form. Therefore, both forms of A. muciniphila could modulate lipid and immune homeostasis, improved some gut microbiota, and promoted the overall health, while all these effects were dominantly observed in pasteurized form. In conclusion, pasteurized A. muciniphila can be considered as new medical supplement to maintain health state and prevent diseases in normal mice through different mechanisms.


Subject(s)
Gastrointestinal Microbiome/drug effects , Homeostasis/drug effects , Lipid Metabolism/drug effects , Probiotics/pharmacology , Akkermansia , Animals , Caco-2 Cells , Humans , Mice
5.
BMC Musculoskelet Disord ; 22(1): 789, 2021 Sep 14.
Article in English | MEDLINE | ID: mdl-34521416

ABSTRACT

BACKGROUND: Ankylosing spondylitis (AS) is an autoimmune rheumatic disease. Few candidate gene associations have been reported for AS and the current understanding of its pathogenesis remains still poor. Thus, the exact mechanism of AS is needed to urgently be disclosed. The purpose of this study was to identify candidate genes involving in AS disease. METHODS AND RESULTS: GSE25101 publicly available microarray and GSE117769 RNA-seq datasets of AS patients were obtained for bioinformatics analyses. Gene set enrichment analysis showed that in the microarray dataset, the ribosome pathway was significantly up-regulated in AS compared with controls. Furthermore, some ribosomal components demonstrated overexpression in patients in the RNA-seq dataset. To confirm the findings, 20 AS patients and 20 matching controls were selected from the Rheumatology Research Center clinic, Shariati Hospital. PBMCs were separated from whole blood and RNA contents were extracted. Following the results of datasets analysis, the expression level of rRNA5.8S pseudogene, rRNA18S pseudogene, RPL23, RPL7, and RPL17 genes were measured through real-time PCR. Our findings showed dysregulation of rRNA5.8S and rRNA18S pseudogenes, and also the RPL17 gene in patients. CONCLUSION: Considering that genes involved in ribosome biogenesis contributed to some AS-associated biological processes as well as diseases that have comorbidities with AS, our results might advance our understanding of the pathological mechanisms of ankylosing spondylitis.


Subject(s)
Spondylitis, Ankylosing , Computational Biology , Humans , Ribosomes/genetics , Spondylitis, Ankylosing/genetics , Systems Biology
6.
Iran J Microbiol ; 13(3): 257-265, 2021 Jun.
Article in English | MEDLINE | ID: mdl-34540163

ABSTRACT

Classical (CKp) and hypervirulent (hvKp) Klebsiella pneumoniae are two different circulating pathotypes. The aim of this study was to assess the prevalence, epidemiology and molecular relatedness of hvKps using a systemic review and meta-analysis. The data extracted from Medline, Embase, and Web of Science and finally 14 studies met the eligible criteria. To combine prevalence proportions of all studies, we performed the metaprop command embedded in the Meta package software. Totally, of 1814 K. pneumoniae isolates, 21.7% (394/1814) were hvKp. The molecular typing showed that all hvKp isolates were grouped into 50 different sequence types (STs) of them ST23, ST11, ST65 and ST86 were common. K1, K2 and K64 were dominant capsule serotypes that strongly related to ST23, ST65 and ST11, respectively. It seems that clonal group 23 (CG23) is associated with liver abscess and CG11 related to various clinical sources.

7.
Microbiol Spectr ; 9(2): e0048421, 2021 10 31.
Article in English | MEDLINE | ID: mdl-34549998

ABSTRACT

Akkermansia muciniphila, as a member of the gut microbiota, has been proposed as a next-generation probiotic. Liver fibrosis is the main determinant of liver dysfunction and mortality in patients with chronic liver disease. In this study, we aimed to determine the beneficial effects of live and pasteurized A. muciniphila and its extracellular vesicles (EVs) on the prevention of liver fibrosis. The response of hepatic stellate cells (HSCs) to live and pasteurized A. muciniphila and its EVs was examined in quiescent, lipopolysaccharide (LPS)-activated LX-2 cells. Liver fibrosis was induced in 8-week-old C57BL/6 mice, using a high-fat diet (HFD) and carbon tetrachloride (CCl4) administration for 4 weeks. The mice were concomitantly treated via oral gavage with three forms of bacteria. The relative expression of different fibrosis and inflammatory markers was assessed in the tissues. Histological markers, serum biochemical parameters, and cytokine production were also analyzed, and their correlations with the relative abundance of targeted fecal bacteria were examined. All A. muciniphila preparations exhibited protective effects against HSC activation; however, EVs showed the greatest activity in HSC regression. Oral gavage with A. muciniphila ameliorated the serum biochemical and inflammatory cytokines and improved liver and colon histopathological damages. The relative expression of fibrosis and inflammatory biomarkers was substantially attenuated in the tissues of all treated mice. The composition of targeted stool bacteria in the live A. muciniphila group was clearly different from that in the fibrosis group. This study indicated that A. muciniphila and its derivatives could successfully protect against HFD/CCl4-induced liver injury. However, further studies are needed to prove the beneficial effects of A. muciniphila on the liver. IMPORTANCE Akkermansia muciniphila, as a member of the gut microbiota, has been proposed as a next-generation probiotic. Liver fibrosis is the main determinant of liver dysfunction and mortality in patients with chronic liver disease. In this study, we aimed to determine the beneficial effects of live and pasteurized A. muciniphila and its extracellular vesicles (EVs) on the prevention of liver fibrosis. The results of the present study indicated that oral administration of live and pasteurized A. muciniphila and its EVs could normalize the fecal targeted bacteria composition, improve the intestinal permeability, modulate inflammatory responses, and subsequently prevent liver injury in HFD/CCl4-administered mice. Following the improvement of intestinal and liver histopathology, HFD/CCl4-induced kidney damage and adipose tissue inflammation were also ameliorated by different A. muciniphila treatments.


Subject(s)
Liver Cirrhosis/prevention & control , Probiotics/administration & dosage , Protective Agents/administration & dosage , Akkermansia/chemistry , Akkermansia/physiology , Animals , Carbon Tetrachloride/adverse effects , Diet, High-Fat , Extracellular Vesicles/chemistry , Feces/microbiology , Hepatic Stellate Cells , Humans , Liver/drug effects , Liver Cirrhosis/chemically induced , Liver Cirrhosis/microbiology , Male , Mice , Mice, Inbred C57BL , Probiotics/chemistry , Protective Agents/chemistry
8.
Int Arch Allergy Immunol ; 182(11): 1113-1121, 2021.
Article in English | MEDLINE | ID: mdl-34161951

ABSTRACT

OBJECTIVES: Ankylosing spondylitis (AS) is a rheumatic disorder that is mostly determined by genetic and environmental factors. Given the known importance of macrophage in AS pathogenesis, we investigated the transcriptional profile of macrophage cells in the disease. METHODS AND RESULTS: Two approaches of differential expression and subsequently, weighted gene co-expression network analysis was utilized to analyze a publicly available microarray dataset of macrophages. Integral membrane protein 2A (ITM2A) was among the most significant genes with a decreased trend in the common results of both methods. In order to confirm the finding, the expression of ITM2A was evaluated in monocyte-derived (M2-like) and M1 macrophages obtained from 14 AS patients and 14 controls. Macrophages were differentiated from whole-blood separated monocytes by 7 days incubating with macrophage colony-stimulating factor and then macrophages specific markers were verified with the flow cytometer. M1 polarization was induced by IFN-γ and lipopolysaccharide. Finally, relative gene expression analysis by real-time polymerase chain reaction revealed a significant downregulation of the ITM2A gene in both M2 like and M1 macrophages of the AS group compared to the control. CONCLUSION: Since ITM2A plays a critical role in osteo- and chondrogenic cellular differentiation, our finding may provide new insights into AS pathogenesis.


Subject(s)
Macrophages/metabolism , Membrane Proteins/genetics , Spondylitis, Ankylosing/genetics , Adult , Cell Differentiation , Cells, Cultured , Down-Regulation , Female , Humans , Male , RNA, Messenger/metabolism , Young Adult
9.
Probiotics Antimicrob Proteins ; 13(6): 1546-1556, 2021 12.
Article in English | MEDLINE | ID: mdl-33852147

ABSTRACT

The gastrointestinal (GI) tract is an essential reservoir of serotonin or 5-hydroxytryptamine (5-HT), which possesses a set of bacterial species communities. Intestinal microbiota has the ability to modulate the host's serotonin system. In this regard, we evaluated the effect of Akkermansia muciniphila and Faecalibacterium prausnitzii along with their extracellular vesicles (EVs) on serotonin system-related genes in human epithelial colorectal adenocarcinoma (Caco-2) cells. The differentiated Caco-2 cells were treated with A. muciniphila and F. prausnitzii with the multiplicity of infection ratio of 1 and 10 and the EV concentration of 1 µg/mL and 50 µg/mL, respectively. After 24 h, the serotonin level was quantified using an ELISA kit and also the gene expression of serotonin system-related genes was examined using the quantitative real-time PCR method. According to the results, treatment with A. muciniphila and F. prausnitzii-derived EVs increased the serotonin level, while none of the bacteria could affect the serotonin level in the Caco-2 cells. Both bacteria had significant effects on the mRNA expression of serotonin system-related genes in the Caco-2 cells. Moreover, we observed that A. muciniphila and F. prausnitzii-derived EVs could impact the expression of major genes involved in the serotonin system. Our findings showed that A. muciniphila and F. prausnitzii along with their EVs could modulate serotonin system-related genes; hence, they may be useful in microbiota modulation therapies to maintain the homeostasis of the serotonin system.


Subject(s)
Extracellular Vesicles , Faecalibacterium prausnitzii , Serotonin/metabolism , Akkermansia , Caco-2 Cells , Humans
10.
Iran J Basic Med Sci ; 23(8): 1053-1058, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32952952

ABSTRACT

OBJECTIVES: We previously conducted an in silico research on the interactions between the ribosome display-selected single chain variable fragment (scFv) and factor H binding protein (fHbp) of Neisseria meningitidis. We found that heavy chain variable (VH) fragment of this scFv had considerable affinity to fHbp. These results led us to evaluate the ability of this small antibody fragment in binding and detection of fHbp antigen. MATERIALS AND METHODS: In this study, at first, the three-dimensional structure of VH fragment was simulated by Kotai Antibody Builder web server. By using ClusPro 2.0 web server, the 3D structure of the soluble form of fHbp (PDB: 2KC0) was docked to the modeled VH fragment to extract the structure of the complex's binding. Molecular dynamics (MD) simulation was carried out using GROMACS 4.5.3 package for 65 ns. Secondly, coding sequence of VH fragment was cloned separately and expressed in Escherichia coli. After purification of the VH fragment, its binding activity to fHbp protein was analyzed by enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR) method. RESULTS: Important amino acids involved in antigen- antibody interaction were identified by analyzing the fHbp-VH complex. The ability of the VH antibody fragment to bind and detect fHbp antigen has been confirmed by the results of in silico analysis, ELISA and SPR methods. CONCLUSION: These results showed that this small fragment of antibody could be used for designing diagnostic kits.

11.
Front Immunol ; 11: 1098, 2020.
Article in English | MEDLINE | ID: mdl-32582184

ABSTRACT

Leishmania parasites are the causative agents of human leishmaniases. They infect professional phagocytes of their mammalian hosts, including dendritic cells (DCs) that are essential for the initiation of adaptive immune responses. These immune functions strictly depend on the DC's capacity to differentiate from immature, antigen-capturing cells to mature, antigen-presenting cells-a process accompanied by profound changes in cellular phenotype and expression profile. Only little is known on how intracellular Leishmania affects this important process and DC transcriptional regulation. Here, we investigate these important open questions analyzing phenotypic, cytokine profile and transcriptomic changes in murine, immature bone marrow-derived DCs (iBMDCs) infected with antibody-opsonized and non-opsonized Leishmania amazonensis (L.am) amastigotes. DCs infected by non-opsonized amastigotes remained phenotypically immature whereas those infected by opsonized parasites displayed a semi-mature phenotype. The low frequency of infected DCs in culture led us to use DsRed2-transgenic parasites allowing for the enrichment of infected BMDCs by FACS. Sorted infected DCs were then subjected to transcriptomic analyses using Affymetrix GeneChip technology. Independent of parasite opsonization, Leishmania infection induced expression of genes related to key DC processes involved in MHC Class I-restricted antigen presentation and alternative NF-κB activation. DCs infected by non-opsonized parasites maintained an immature phenotype and showed a small but significant down-regulation of gene expression related to pro-inflammatory TLR signaling, the canonical NF-kB pathway and the NLRP3 inflammasome. This transcriptomic profile was further enhanced in DCs infected with opsonized parasites that displayed a semi-mature phenotype despite absence of inflammasome activation. This paradoxical DC phenotype represents a Leishmania-specific signature, which to our knowledge has not been observed with other opsonized infectious agents. In conclusion, systems-analyses of our transcriptomics data uncovered important and previously unappreciated changes in the DC transcription factor landscape, thus revealing a novel Leishmania immune subversion strategy directly acting on transcriptional control of gene expression. Our data raise important questions on the dynamic and reciprocal interplay between trans-acting and epigenetic regulators in establishing permissive conditions for intracellular Leishmania infection and polarization of the immune response.


Subject(s)
Dendritic Cells/immunology , Dendritic Cells/parasitology , Host-Parasite Interactions/immunology , Inflammasomes/immunology , Leishmaniasis/immunology , Animals , Female , Leishmania mexicana/immunology , Mice , Mice, Inbred BALB C , Transcriptome/immunology
12.
Microb Pathog ; 144: 104200, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32289465

ABSTRACT

The human gut harbors diverse microbes that play a fundamental role in the well-being of their host. Microbiota disruption affects the immune function, metabolism, and causes several diseases. Therefore, understanding how the microbiome is adjusted, and identifying methods for manipulating it is critical. Studies have found that there is an inverse association between MicroRNAs (miRNAs) abundance and microbe abundance. miRNAs are known to be engaged in post-transcription regulation of cell-autonomous gene expression. Recently, they have gained great attention for their proposed roles in cell-to-cell communication, and as biomarkers for human disease. Here, we review recent studies on the role of miRNAs as a component of outer membrane vesicles (OMVs) in the composition of gut microbiota and their significance in the human situation of health and diseases and discuss their effect on inflammatory responses and dysbiosis. Further, we explain how probiotics exert influence on the expression of miRNAs.


Subject(s)
Gastrointestinal Microbiome/physiology , MicroRNAs/metabolism , Animals , Biomarkers , Dysbiosis/immunology , Gastrointestinal Microbiome/immunology , Gene Expression , Host Microbial Interactions/immunology , Host Microbial Interactions/physiology , Humans , Probiotics
13.
Clin Interv Aging ; 15: 321-327, 2020.
Article in English | MEDLINE | ID: mdl-32184581

ABSTRACT

OBJECTIVE: Osteoarthritis is the most common type of arthritis and one of the leading causes of job loss and motor disabilities. Recently, the involvement of dopaminergic pathways and dopamine receptor genes has been considered in this disease. Therefore, studying and comparing the expression pattern of these receptor genes can lead to a greater understanding of the pathogenesis of this disease. METHODS: In this research, we used the systems biology approach to investigate the role of the dopaminergic pathway in osteoarthritis. Then the gene expression pattern of dopamine receptor genes was examined in an osteoarthritis patientgroup in comparison with healthy individuals by Real-time PCR method. RESULTS: The analysis of the transcriptome dataset of osteoarthritis identified some genes in the dopaminergic pathway and the six most important genes in this disease are in the network with a significant relationship to dopamine receptors which differentially expressed compared to health groups. Statistical analysis of the case control study showed a significant difference (P-value<0.05) in DRD1 and DRD2 family in the patients in comparison to healthy individuals. DISCUSSION: We attained the significant expression pattern of dopamine receptors in the blood of osteoarthritis patients which could be useful to identify new strategies for the diagnosis, management, or treatment of this disease.


Subject(s)
Dopamine/metabolism , Osteoarthritis/metabolism , Receptors, Dopamine/metabolism , Case-Control Studies , Female , Humans , Male , Receptors, Dopamine D2/metabolism , Systems Biology , Transcriptome
14.
Front Microbiol ; 10: 2155, 2019.
Article in English | MEDLINE | ID: mdl-31632356

ABSTRACT

Recent evidence suggests that probiotics can restore the mucosal barrier integrity, ameliorate inflammation, and promote homeostasis required for metabolism in obesity by affecting the gut microbiota composition. In this study, we investigated the effect of Akkermansia muciniphila and its extracellular vesicles (EVs) on obesity-related genes in microarray datasets and evaluated the cell line and C57BL/6 mice by conducting RT-PCR and ELISA assays. A. muciniphila-derived EVs caused a more significant loss in body and fat weight of high-fat diet (HFD)-fed mice, compared with the bacterium itself. Moreover, treatment with A. muciniphila and EVs had significant effects on lipid metabolism and expression of inflammatory markers in adipose tissues. Both treatments improved the intestinal barrier integrity, inflammation, energy balance, and blood parameters (i.e., lipid profile and glucose level). Our findings showed that A. muciniphila-derived EVs contain various biomolecules, which can have a positive impact on obesity by affecting the involved genes. Also, our results showed that A. muciniphila and its EVs had a significant relationship with intestinal homeostasis, which highlights their positive role in obesity treatment. In conclusion, A. muciniphila-derived EVs can be used as new therapeutic strategies to ameliorate HFD-induced obesity by affecting various mechanisms.

15.
Appl Microbiol Biotechnol ; 103(4): 1725-1735, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30607487

ABSTRACT

Fructosyl peptide oxidase (FPOX, EC 1.5.3) belongs to the family of oxidoreductases, which is used as a diagnostic enzyme for diabetes mellitus. FPOX has activities toward Fru-ValHis and Fru-Lys as model compounds for hemoglobin A1c (HbA1c) and glycated albumin, respectively. However, when the concentration of HbA1c is measured, the activity toward Fru-Lys will cause interference. In this study, we focused on the substrate specificity engineering of FPOX from Eupenicillium terrenum through computational and experimental methods with characteristics more suitable for HbA1c measurement in the blood. Based on structural knowledge of E. terrenum FPOX (PDB ID 4RSL) and molecular modeling results, residues His-377, Arg-62, Lys-380, and Tyr-261 were selected as mutagenesis sites. The best mutant with lower binding energy, stronger hydrophobic interactions, and more hydrogen bonds with Fru-ValHis and higher binding energy toward Fru-Lys was selected for experimental studies. To investigate the conformational changes in FPOX due to the mutation, molecular dynamics simulation was also performed. The genes encoding of native and engineered variants were cloned into pET-22b(+) and produced in Escherichia coli strain BL21 (DE3). The expressed recombinant enzymes were purified and their kinetic properties were studied. Substitution of Tyr261 with Trp resulted in a mutant enzyme with improved specificity for Fru-ValHis, a model compound of HbA1c. The specific activity of mutant FPOX increased by 5.1-fold to 145.2 ± 3.2 U/mg for Fru-ValHis and decreased by 13.7-fold to 1.3 U/mg ± 0.9 for Fru-Lys compared to the native variant. Kinetics analysis indicated that Tyr261Trp FPOX mutant had 11.7-fold increase in Kcat/Km for Fru-ValHis compared to the wild-type enzyme, while the Kcat/Km for Fru-Lys diminished by 22.4-fold. In summary, our computational and experimental results suggested that the engineered FPOX is a good candidate to efficient determination of HbA1c.


Subject(s)
Amino Acid Oxidoreductases/metabolism , Eupenicillium/enzymology , Glycated Hemoglobin/analysis , Mutant Proteins/metabolism , Recombinant Proteins/metabolism , Amino Acid Oxidoreductases/chemistry , Amino Acid Oxidoreductases/genetics , Genetic Engineering , Mutant Proteins/chemistry , Mutant Proteins/genetics , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Substrate Specificity
16.
Daru ; 21(1): 67, 2013 Dec 19.
Article in English | MEDLINE | ID: mdl-24355111

ABSTRACT

BACKGROUND AND THE PURPOSE OF THE STUDY: Modafinil, a novel wake-promoting agent with low potential for abuse and dependence, has a reliable structure to find some novel derivatives with better activity and lower potential for abuse and risk of dependency. This study was designed to evaluate psychobiological activity of some novel N-aryl modafinil derivatives. METHODS: Seven novel N-aryl modafinil derivatives were synthesized through three reactions: a) preparation of benzhydrylsulfanyl acetic acid through reaction of benzhydrol with thioglycolic acid, b) formation of desired amide by adding the substituted aniline to activated acid with EDC (1-ethyl-3-(3-dimethyl amino propyl) carbodiimide). This reaction was catalyzed by HOBt (N- hydroxylbenzotriazole), and c) oxidation of sulfur to sulfoxide group with H2O2. Then, their psychobiological effect on the performance of male albino mice were compared to that of modafinil as following: wakefulness by determining the effects of derivatives on phenobarbital-induced loss of the righting reflex (LOPR); exploratory activity by measuring activity in the open field test (OFT); depression by measuring immobility time (IT) during forced swimming test (FST) and the anxiogenic and anxiolytic like effects by using elevated plus-maze test (EPM). All tests were videotaped and analyzed for the frequency and duration of the behaviors during the procedures. CONCLUSIONS: 2-(Benzhydrylsulfonyl)-N-(4-chlorophenyl)acetamide (4c) showed comparable result in LOPR test. However, all analogs were found to be stimulant except 2-(benzhydrylsulfinyl)-N-phenylacetamide (4a). Also 4c led the most exploratory activity in mice among derivatives. FST results showed that 4a had the longest IT while modafinil, 2-(benzhydrylsulfinyl)-N-(3-chlorophenyl) acetamide (4b) and 2-(benzhydrylsulfinyl)-N-(4-ethylphenyl) acetamide (4d) had the shortest IT. In EPM, all derivatives showed anxiogenic-like behavior since they decreased open arms time and open arms entries and simultaneously increased close arms time.

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