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1.
Front Microbiol ; 15: 1349239, 2024.
Article in English | MEDLINE | ID: mdl-38562468

ABSTRACT

Chenopodium quinoa manifests adaptability to grow under varying agro-climatic scenarios. Assessing quinoa germplasm's phenotypic and genetic variability is a prerequisite for introducing it as a potential candidate in cropping systems. Adaptability is the basic outcome of ecological genomics of crop plants. Adaptive variation predicted with a genome-wide association study provides a valuable basis for marker-assisted breeding. Hence, a panel of 72 quinoa plants was phenotyped for agro morphological attributes and association-mapping for distinct imperative agronomic traits. Inter simple sequence repeat (ISSR) markers were employed to assess genetic relatedness and population structure. Heatmap analysis showed three genotypes were early maturing, and six genotypes were attributed for highest yield. The SD-121-07 exhibited highest yield per plant possessing green, glomerulate shaped, compact density panicle with less leaves. However, SJrecm-03 yielded less exhibiting pink, intermediate shape, intermediate density panicles with less leaves. The phenotyping revealed strong correlation of panicle architecture with yield in quinoa. A genome-wide association study unraveled the associations between ISSR makers and agro-morphological traits. Mixed linear modes analysis yielded nine markers associated with eight traits at p ≤ 0.01. Moreover, ISSR markers significantly associated with panicle shape and leafiness were also associated with yield per plant. These findings contribute to the provision of authenticity for marker-assisted selection that ultimately would support quinoa breeding programs.

2.
Front Plant Sci ; 14: 1235848, 2023.
Article in English | MEDLINE | ID: mdl-38089797

ABSTRACT

Quantitative real-time PCR is used to quantify gene expression, even to detect low-level transcripts. It detects and quantifies the inoculum level of fungal pathogens in infected hosts. However, reliable expression profiling data require accurate transcript normalization against a stable reference gene. Hence, using stably expressed reference genes under variable conditions is paramount in gene expression analysis. In the current study, reference genes were selected and validated in Colletotrichum gloeosporioides, a guava canker and dieback pathogen. The reference gene selection and validation in C. gloeosporioides were evaluated for germinated conidia and mycelium (in vitro) and in infected guava (Psidium guajava) (interaction with host plant). The CgCAL gene was determined as a highly stable reference gene, followed by the CgTUB2 in C. gloeosporioides for germinating conidia and mycelium. However, the CgTUB2 gene was determined to be a highly stable reference gene, followed by the CgCAL for expression analysis during its interaction with the plant. Expression profiling revealed stable and constant relative expression patterns of selected reference genes for both PR genes by determining their relative transcript level. This study is the first to describe reference gene selection and validation to quantify target gene expression in C. gloeosporioides.

3.
Front Plant Sci ; 14: 1134806, 2023.
Article in English | MEDLINE | ID: mdl-37908834

ABSTRACT

Plant immunity includes enemy recognition, signal transduction, and defensive response against pathogens. We experimented to identify the genes that contribute resistance against dieback disease to Dalbergia sissoo, an economically important timber tree. In this study, we investigated the role of three differentially expressed genes identified in the dieback-induced transcriptome in Dalbergia sissoo. The transcriptome was probed using DOP-rtPCR analysis. The identified RGAs were characterized in silico as the contributors of disease resistance that switch on under dieback stress. Their predicted fingerprints revealed involvement in stress response. Ds-DbRCaG-02-Rga.a, Ds-DbRCaG-04-Rga.b, and Ds-DbRCaG-06-Rga.c showed structural homology with the Transthyretin-52 domain, EAL associated YkuI_C domain, and Src homology-3 domain respectively, which are the attributes of signaling proteins possessing a role in regulating immune responses in plants. Based on in-silico structural and functional characterization, they were predicted to have a role in immune response regulation in D. sissoo.

4.
Front Plant Sci ; 14: 1168221, 2023.
Article in English | MEDLINE | ID: mdl-37021314

ABSTRACT

We investigated the in silico characterization of short-length nucleotide sequences that were differentially expressed in dieback stress-induced transcriptomic analysis. They displayed homology with C-terminal flanking peptides and defensins-like proteins, revealing their antimicrobial activity. Their predicted fingerprints displayed protein signatures related to antimicrobial peptides. These short-length RGAs have been shown to possess structural motifs such as APLT P-type ATPase, casein kinase II (CK2), protein kinase 3, protein kinase C (PKC), and N-glycosylation site that are the attributes of disease resistance genes. The prediction of arginine and lysine residues in active binding sites in ligand docking analysis prophesied them as antimicrobial peptides due to their strong relation with antimicrobial activity. The in silico structural-functional characterization has predicted their role in resistance against microbial pathogens. Moreover, the predicted antimicrobial peptide regions showed their homology with the signature domain of PR-5-like protein and AMP family Thaumatin.

5.
Front Genet ; 14: 1136688, 2023.
Article in English | MEDLINE | ID: mdl-36999059

ABSTRACT

Dalbergia sissoo is one of the most economically important trees in forestry, agroforestry, and horticulture. This tree species is severely threatened by dieback. Widespread dieback outbreaks and infestations have drastically destroyed billions of D. sissoo trees. Hence, we attempted to resolve the dieback etiology through phylogenomics associated with D. sissoo mortality. The Ceratocystis species was evaluated using morphologically investigated fungal isolates collected from dieback-affected tissue plants. Based on the symptomatology, we have differentiated dieback from Fusarium wilt and concluded that the Ceratocystis fimbriata sensu lato complex is causing shisham dieback in Pakistan. As the Ceratocystis species complex is a cryptic species complex, we used genomics and phylogenetic analysis for deciphering its evolutionary hierarchical order. The pathogen's operational taxonomy was unlocked with the help of phylogenomics, and it was discovered that isolates from D. sissoo represent a species distinct from the other species in the C. fimbriata sensu lato species complex. The name Ceratocystis dalbergicans sp. nov. has been given to the fungus causing dieback disease in D. sissoo.

6.
Physiol Mol Biol Plants ; 29(1): 1-10, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36733839

ABSTRACT

We investigated the role of the DDTFR10/A gene of the ethylene response element-binding protein (EREBP) family through the CRISPR/Cas9 genome editing approach. The associated role of this gene in tomato fruit ripening was known. The involvement of ripening-regulatory proteins in plant defense has been documented; therefore, to find the involvement of the DDTFR10/A gene in host susceptibility, we introduced the mutation in DDTFR10/A gene through CRISPR/cas9 in the genome of the tomato plant. The 50% biallelic and 50% homozygous mutations were observed in the T0 generation. The CRISPR/Cas9 edited plants showed 40% reduced symptoms of Fusarium wilt compared to control plants (non-edited). The DDTFR10/A gene expression in tomato plants was evaluated against biotic (Fusarium wilt) and abiotic (salinity) stresses, and the upregulated expression of this gene was found under both challenges. However, a comparative increase in DDTFR10/A gene expression was observed in tomato plants upon inoculation with Fusarium oxysporum f. sp. lycopersici. The phenotypic assay performed on edited tomato plants demonstrated the role of the DDTFR10/A gene in contributing toward susceptibility against Fusarium wilt. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01273-6.

7.
Physiol Mol Biol Plants ; 29(12): 1959-1979, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38222284

ABSTRACT

Chenopodium quinoa possesses remarkable nutritional value and adaptability to various agroecological conditions. Panicle architecture influences the number of spikelets and grains in a panicle, ultimately leading to productivity and yield. Therefore, this study aimed to investigate the metabolites, nutrients, and minerals in Chenopodium quinoa accessions of varying panicle architecture. Metabolic profiling using liquid chromatography-mass spectrometry (LC-MS) analysis identified seventeen metabolites, including flavonoids, phenolics, fatty acids, terpenoids, phenylbutenoid dimers, amino acids, and saccharides. Eight metabolic compounds were reported in this study for the first time in quinoa. Some metabolites were detected as differentially expressed. The compound (Z)-1-(2,4,5-trimethoxyphenyl) butadiene and chrysin were found only in SPrecm. Sodium ((2R,3S,4R,5R)-5-(6-amino-9H-purin-9-yl)-3,4-dihydroxtetrahydrofuran-2-yl) methyl hydrogen phosphate and elenolic acid were detected only in CHEN-33, and quercetin, 3-hydroxyphloretin-3'-C-glucoside, kurarinone, and rosmarinic acid were identified only in D-12175. Variable importance in projection (VIP) scores annotated ten metabolites contributing to variability. Mineral analysis using atomic absorption spectrophotometry indicated that the quantity of magnesium and calcium is high in D-12175. In comparison, SPrecm showed a high quantity of magnesium compared to CHEN-33, while CHEN-33 showed a high quantity of calcium compared to SPrecm. However, the proximate composition showed no significant difference among quinoa accessions. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-023-01398-2.

8.
Front Genet ; 13: 1036029, 2022.
Article in English | MEDLINE | ID: mdl-36276980

ABSTRACT

Dalbergia sissoo is an important timber tree, and dieback disease poses a dire threat to it toward extinction. The genomic record of D. sissoo is not available yet on any database; that is why it is challenging to probe the genetic elements involved in stress resistance. Hence, we attempted to unlock the genetics involved in dieback resistance through probing the NBS-LRR family, linked with mostly disease resistance in plants. We analyzed the transcriptome of D. sissoo under dieback challenge through DOP-rtPCR analysis using degenerate primers from conserved regions of NBS domain-encoded gene sequences. The differentially expressed gene sequences were sequenced and in silico characterized for predicting the expressome that contributes resistance to D. sissoo against dieback. The molecular and bioinformatic analyses predicted the presence of motifs including ATP/GTP-binding site motif A (P-loop NTPase domain), GLPL domain, casein kinase II phosphorylation site, and N-myristoylation site that are the attributes of proteins encoded by disease resistance genes. The physicochemical characteristics of identified resistance gene analogs, subcellular localization, predicted protein fingerprints, in silico functional annotation, and predicted protein structure proved their role in disease and stress resistance.

9.
Plants (Basel) ; 11(19)2022 Oct 08.
Article in English | MEDLINE | ID: mdl-36235510

ABSTRACT

Pathogenicity-associated genes are highly host-specific and contribute to host-specific virulence. We tailored the traditional Koch's postulates with integrative omics by hypothesizing that the effector genes associated with host-pathogenicity are determinant markers for virulence, and developed Integrative Pathogenicity (IP) postulates for authenticated pathogenicity testing in plants. To set the criteria, we experimented on datepalm (Phoenix dactylifera) for the vascular wilt pathogen and confirmed the pathogen based on secreted in xylem genes (effectors genes) using genomic and transcriptomic approaches, and found it a reliable solution when pathogenicity is in question. The genic regions ITS, TEF1-α, and RPBII of Fusarium isolates were examined by phylogenetic analysis to unveil the validated operational taxonomy at the species level. The hierarchical tree generated through phylogenetic analysis declared the fungal pathogen as Fusarium oxysporum. Moreover, the Fusarium isolates were investigated at the subspecies level by probing the IGS, TEF1-α, and Pgx4 genic regions to detect the forma specialis of F. oxysporum that causes wilt in datepalm. The phylogram revealed a new forma specialis in F. oxysporum that causes vascular wilt in datepalm.

10.
Mol Biol Rep ; 49(12): 11675-11684, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36178561

ABSTRACT

BACKGROUND: Disease-resistant cultivars are the best solution to get their maximum yield potential and avoid fungicide application. There is no doubt about the contribution, and use of R genes (resistance genes) in resistance development in plants, while S genes (susceptibility genes) also hold a strong position in pathogenesis by resistance repression, and their loss of function contributes to enhanced resistance. Hence, we attempted to knock out the function of the StERF3 gene in potatoes through CRISPR/Cas9-based genome editing and investigated the CRISPR/Cas9 approach as strategic control against late blight disease in potato plants. METHODS AND RESULTS: The StERF3 gene was edited in late blight susceptible cv. Lady Rosetta. Full allelic edited plants were identified through DnpI, and N1aIV mediated restriction digestion and then further analyzed through Indel Detection by Amplicon Analysis. Sequence analysis of targeted plants for indel identification showed full allelic editing. The detached leaf assay of full allelic edited plants demonstrated the role of the StERF3 gene in susceptibility to late blight in potatoes. In planta disease assay also showed reduced, slowed, and delayed disease progression in StERF3-loss-of-function mutants compared to wild-type (control) plants. Less fungal biomass was quantified in knockouts through Real-time qPCR that supported less susceptibility of edited plants to late blight. Besides, relatively high expression of pathogens-related genes, StPR1, and StNPR1, were also observed in StERF3-loss-of-function mutants compared to the corresponding control. CONCLUSION: The results showed the functional inhibition of StERF3 genes using the CRISPR/Cas9 approach. The functional knockouts (StERF3 gene-edited potato plants) revealed enhanced resistance against Phytophthora infestans, thereby demonstrating the best strategic control for late blight disease in potato plants.


Subject(s)
Phytophthora infestans , Solanum tuberosum , Humans , Solanum tuberosum/genetics , CRISPR-Cas Systems/genetics , Plant Diseases/genetics , Plant Diseases/microbiology , Phytophthora infestans/genetics , Genes, Plant , Disease Resistance/genetics
11.
Clin Exp Hypertens ; 44(6): 557-566, 2022 Aug 18.
Article in English | MEDLINE | ID: mdl-35635242

ABSTRACT

BACKGROUND: Phytolaccagenin, a natural triterpenoid, is reported for various biological activities that indicate its potential role in the management of hypertension. METHODS: Phytolaccagenin was evaluated for its antihypertensive activity in rat models via in vivo and in vitro experiments using polyethylene tubings for cannulation, organ bath bubbled with carbogen gas, and a pressure transducer connected to a PowerLab data acquisition system. RESULTS: Intravenous administration of phytolaccagenin decreased mean arterial pressure (MAP), significantly, in normotensive and hypertensive anesthetized rats. Pretreatment of rats with atropine (2 mg/kg) partially reversed the decrease in blood pressure due to phytolaccagenin at first tested doses. However, Nω-nitro-L-arginine methyl ester (L-NAME) (100 mg/kg) pretreatment modified the effect of phytolaccagenin on blood pressure with greater response. In isolated rat aortic rings precontracted with phenylephrine, cumulative addition of phytolaccagenin induced relaxation that is ablated (50%) with denudation and pre-incubation with atropine (1 µM) and L-NAME (10 µM). Phytolaccagenin also partially inhibited high K+ precontraction at initial doses, while an inhibitory effect was observed at higher concentrations, confirming its effect on voltage-dependent calcium channels. In isolated spontaneously beating rat atrial strips, phytolaccagenin suppressed the atrial tone that was reduced with isoprenaline and atropine pre-incubation, suggesting the role of cardiac adrenergic and muscarinic receptors. Interestingly, atenolol (1 µM) pretreatment also ablated the cardiac effects of phytolaccagenin. CONCLUSION: The antihypertensive effect of phytolaccagenin is due to a decrease in vascular resistance and cardiac depressant effects. These effects are mediated via muscarinic receptors-linked NO pathway, inhibitory effect on Ca2+ movements (vascular), and activation of cardiac muscarinic and blockade of ß-adrenergic receptors.


Subject(s)
Antihypertensive Agents , Hypertension , Animals , Antihypertensive Agents/pharmacology , Antihypertensive Agents/therapeutic use , Atropine Derivatives/pharmacology , Atropine Derivatives/therapeutic use , Blood Pressure , Endothelium, Vascular , Hypertension/drug therapy , NG-Nitroarginine Methyl Ester/pharmacology , Nitric Oxide/metabolism , Rats , Rats, Sprague-Dawley , Receptors, Muscarinic/therapeutic use , Vasodilation
12.
BMC Med Inform Decis Mak ; 22(1): 90, 2022 04 04.
Article in English | MEDLINE | ID: mdl-35379228

ABSTRACT

BACKGROUND: The digital pathology images obtain the essential information about the patient's disease, and the automated nuclei segmentation results can help doctors make better decisions about diagnosing the disease. With the speedy advancement of convolutional neural networks in image processing, deep learning has been shown to play a significant role in the various analysis of medical images, such as nuclei segmentation, mitosis detection and segmentation etc. Recently, several U-net based methods have been developed to solve the automated nuclei segmentation problems. However, these methods fail to deal with the weak features representation from the initial layers and introduce the noise into the decoder path. In this paper, we propose a multiscale attention learning network (MSAL-Net), where the dense dilated convolutions block captures more comprehensive nuclei context information, and a newly modified decoder part is introduced, which integrates with efficient channel attention and boundary refinement modules to effectively learn spatial information for better prediction and further refine the nuclei cell of boundaries. RESULTS: Both qualitative and quantitative results are obtained on the publicly available MoNuseg dataset. Extensive experiment results verify that our proposed method significantly outperforms state-of-the-art methods as well as the vanilla Unet method in the segmentation task. Furthermore, we visually demonstrate the effect of our modified decoder part. CONCLUSION: The MSAL-Net shows superiority with a novel decoder to segment the touching and blurred background nuclei cells obtained from histopathology images with better performance for accurate decoding.


Subject(s)
Image Processing, Computer-Assisted , Neural Networks, Computer , Attention , Humans , Image Processing, Computer-Assisted/methods
13.
Clin Exp Hypertens ; 43(8): 723-729, 2021 Nov 17.
Article in English | MEDLINE | ID: mdl-34396877

ABSTRACT

Background/objectives: Steroidal saponins are widely distributed in medicinal plants with potential applications in cardiovascular disorders. Gitogenin, a saponin, has not been explored as antihypertensive; this investigation was aimed to explore its blood pressure lowering potential and underlying mechanisms.Methodology: The effect of gitogenin was evaluated on blood pressure in vivo, using normotensive rat model and the underlying cardiovascular mechanism(s) in vitro, in isolated rat aorta and in atria preparations using PowerLab data acquisition system (ADInstrument, Australia).Results: Intravenous injection of gitogenin decreased mean arterial pressure (MAP) in anesthetized rats. Atropine (1 mg/kg) and L-NAME (100 mg/kg) pretreatment significantly (*p < .05) attenuated effect on MAP to gitogenin. In isolated intact aortic rings, gitogenin induced endothelium-dependent vasodilatation (maximum 65%), which was ablated (maximum 22%) with L-NAME (100 mg/kg) and atropine (1 µM) pretreatment or endothelium removal. Gitogenin was found more potent against angiotensin II precontractions without effect on high K+ and low K+ precontractions. In isolated rat right atria, gitogenin suppressed rate and force of contractions. Atropine (1 µM) pretreatment partially inhibited effect of gitogenin on force and eliminated its effect on rate. Combined atropine (10 µM) and atenolol (0.5 µM) pretreatment was without effect on force of contractions but eliminated effect of gitogenin on rate with 25% increase.Conclusion: These findings indicate that antihypertensive effect of gitogenin is the outcome of vascular and cardiac effects; agonistic effect on vascular M3 and cardiac M2 receptors; and being more selective for M2. Increase in the rate of atrial contraction might be of clinical importance.


Subject(s)
Hypertension , Saponins , Animals , Aorta, Thoracic , Blood Pressure , Endothelium, Vascular , Hypertension/drug therapy , Rats , Rats, Sprague-Dawley , Saponins/pharmacology , Spirostans , Vasodilation
14.
Bioorg Med Chem Lett ; 41: 127973, 2021 06 01.
Article in English | MEDLINE | ID: mdl-33753261

ABSTRACT

α1-antitrypsin deficiency is characterised by the misfolding and intracellular polymerisation of mutant α1-antitrypsin protein within the endoplasmic reticulum (ER) of hepatocytes. Small molecules that bind and stabilise Z α1-antitrypsin were identified via a DNA-encoded library screen. A subsequent structure based optimisation led to a series of highly potent, selective and cellular active α1-antitrypsin correctors.


Subject(s)
Drug Design , Protein Folding , alpha 1-Antitrypsin/metabolism , Crystallization , Drug Development/methods , Drug Evaluation, Preclinical , Endoplasmic Reticulum/metabolism , Gene Library , Hepatocytes/metabolism , Humans , Models, Molecular , Protein Conformation , alpha 1-Antitrypsin/genetics
15.
EMBO Mol Med ; 13(3): e13167, 2021 03 05.
Article in English | MEDLINE | ID: mdl-33512066

ABSTRACT

Severe α1 -antitrypsin deficiency results from the Z allele (Glu342Lys) that causes the accumulation of homopolymers of mutant α1 -antitrypsin within the endoplasmic reticulum of hepatocytes in association with liver disease. We have used a DNA-encoded chemical library to undertake a high-throughput screen to identify small molecules that bind to, and stabilise Z α1 -antitrypsin. The lead compound blocks Z α1 -antitrypsin polymerisation in vitro, reduces intracellular polymerisation and increases the secretion of Z α1 -antitrypsin threefold in an iPSC model of disease. Crystallographic and biophysical analyses demonstrate that GSK716 and related molecules bind to a cryptic binding pocket, negate the local effects of the Z mutation and stabilise the bound state against progression along the polymerisation pathway. Oral dosing of transgenic mice at 100 mg/kg three times a day for 20 days increased the secretion of Z α1 -antitrypsin into the plasma by sevenfold. There was no observable clearance of hepatic inclusions with respect to controls over the same time period. This study provides proof of principle that "mutation ameliorating" small molecules can block the aberrant polymerisation that underlies Z α1 -antitrypsin deficiency.


Subject(s)
alpha 1-Antitrypsin Deficiency , alpha 1-Antitrypsin , Animals , Endoplasmic Reticulum , Hepatocytes , Mice , alpha 1-Antitrypsin/genetics
16.
Orbit ; 39(1): 53-60, 2020 Feb.
Article in English | MEDLINE | ID: mdl-30821588

ABSTRACT

This case report deals with two patients with lacrimal sac swellings. Case 1 presented with bilateral sac swelling and Case 2 with a unilateral presentation. Dacrocystorhinostomy (DCR) followed by biopsies of both sacs in Case 1 revealed inflammatory polyps of the sac mucosa, identical in appearance to typical nasal allergic inflammatory polyps. The biopsies were accompanied by typical allergic mucin, featuring tiered mucin layers between which were numerous eosinophils, accompanied by Charcot-Leyden crystals. The histology of the dacryocystectomy specimen for Case 2 showed identical histopathological changes with the additional feature of prominent numbers of Immunoglobulin G (IgG)4-positive plasma cells in the stroma of the lacrimal sac inflammatory polyps. These features extend the sites affected by allergic inflammatory polyps and allergic mucin and possible pathogenesis is discussed.


Subject(s)
Dacryocystorhinostomy/methods , Lacrimal Apparatus/pathology , Mycoses/diagnostic imaging , Nasal Polyps/surgery , Nasolacrimal Duct/pathology , Aged , Biopsy, Needle , Follow-Up Studies , Humans , Hypersensitivity/immunology , Hypersensitivity/physiopathology , Immunohistochemistry , Lacrimal Apparatus/diagnostic imaging , Lacrimal Apparatus/surgery , Male , Middle Aged , Mucins/metabolism , Mycoses/drug therapy , Mycoses/pathology , Nasal Polyps/diagnostic imaging , Nasal Polyps/pathology , Nasolacrimal Duct/diagnostic imaging , Nasolacrimal Duct/surgery , Sampling Studies , Tomography, X-Ray Computed/methods , Treatment Outcome
18.
Methods Mol Biol ; 1639: 235-248, 2017.
Article in English | MEDLINE | ID: mdl-28752464

ABSTRACT

Many serpinopathies, including alpha-1 antitrypsin (A1AT) deficiency, are associated with the formation of unbranched polymer chains of mutant serpins. In vivo, this deficiency is the result of mutations that cause kinetic or thermodynamic destabilization of the molecule. However, polymerization can also be induced in vitro from mutant or wild-type serpins under destabilizing conditions. The characteristics of the resulting polymers are dependent upon induction conditions. Due to their relationship to disease, serpin polymers, mainly those formed from A1AT, have been widely studied. Here, we describe Förster resonance energy transfer (FRET) and gel-based approaches for their characterization.


Subject(s)
Electrophoresis/methods , Fluorescence Resonance Energy Transfer/methods , Polymerization , alpha 1-Antitrypsin/analysis , Electrophoresis, Polyacrylamide Gel , Fluorescence , Humans , Temperature
19.
FEBS J ; 284(13): 2110-2126, 2017 07.
Article in English | MEDLINE | ID: mdl-28504839

ABSTRACT

Severe alpha-1-antitrypsin deficiency (AATD) is most frequently associated with the alpha-1-antitrypsin (AAT) Z variant (E342K). ZZ homozygotes exhibit accumulation of AAT as polymers in the endoplasmic reticulum of hepatocytes. This protein deposition can lead to liver disease, with the resulting low circulating levels of AAT predisposing to early-onset emphysema due to dysregulation of elastinolytic activity in the lungs. An increasing number of rare AAT alleles have been identified in patients with severe AATD, typically in combination with the Z allele. Here we report a new mutation (E75V) in a patient with severe plasma deficiency, which we designate Trento. In contrast to the Z mutant, Trento AAT was secreted efficiently when expressed in cellular models but showed compromised conformational stability. Polyacrylamide gel electrophoresis (PAGE) and ELISA-based analyses of the secreted protein revealed the presence of oligomeric species with electrophoretic and immunorecognition profiles different from those of Z and S (E264V) AAT polymers, including reduced recognition by conformational monoclonal antibodies 2C1 and 4B12. This altered recognition was not due to direct effects on the epitope of the 2C1 monoclonal antibody which we localized between helices E and F. Structural analyses indicate the likely basis for polymer formation is the loss of a highly conserved stabilizing interaction between helix C and the posthelix I loop. These results highlight this region as important for maintaining native state stability and, when compromised, results in the formation of pathological polymers that are different from those produced by Z and S AAT.


Subject(s)
Genetic Predisposition to Disease/genetics , Mutation , alpha 1-Antitrypsin Deficiency/genetics , alpha 1-Antitrypsin/genetics , Electrophoresis, Polyacrylamide Gel , Enzyme-Linked Immunosorbent Assay , Humans , Male , Middle Aged , Molecular Dynamics Simulation , Polymerization , Protein Conformation , alpha 1-Antitrypsin/chemistry , alpha 1-Antitrypsin/metabolism , alpha 1-Antitrypsin Deficiency/blood , alpha 1-Antitrypsin Deficiency/metabolism
20.
Int J Antimicrob Agents ; 49(6): 719-726, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28390963

ABSTRACT

A topical antimicrobial, silver oxynitrate (Ag7NO11), has recently become available that exploits the antimicrobial activity of ionic silver but has enhanced activity because highly oxidised silver atoms are stabilised with oxygen in a unique chemical formulation. The objective of this study was to use a multifaceted approach to characterise the spectrum of antimicrobial and antibiofilm activity of a wound dressing coated with Ag7NO11 at a concentration of 0.4 mg Ag/cm2. Physiochemical properties that influence efficacy were also evaluated, and Ag7NO11 was found to release a high level of Ag ions, including Ag2+ and Ag3+, without influencing the pH of the medium. Time-kill analysis demonstrated that a panel of multidrug-resistant pathogens isolated from wound specimens remained susceptible to Ag7NO11 over a period of 7 days, even with repeated inoculations of 1 × 106 CFU/mL to the dressing. Furthermore, established 72-h-old biofilms of Pseudomonas aeruginosa, Staphylococcus aureus and two carbapenem-resistant Gram-negative bacteria (blaNDM-1-positive Klebsiella pneumoniae and blaVIM-2-positive P. aeruginosa) were disrupted and eradicated by Ag7NO11 in vitro. Ag7NO11 is a proprietary compound that exploits novel Ag chemistry and can be considered a new class of topical antimicrobial agent. Biocompatibility testing has concluded Ag7NO11 to be non-toxic for cytotoxicity, acute systemic toxicity, irritation and sensitisation.


Subject(s)
Anti-Bacterial Agents/pharmacology , Biofilms/drug effects , Klebsiella pneumoniae/drug effects , Pseudomonas aeruginosa/drug effects , Silver Compounds/pharmacology , Staphylococcus aureus/drug effects , Klebsiella pneumoniae/physiology , Microbial Sensitivity Tests , Microbial Viability/drug effects , Pseudomonas aeruginosa/physiology , Staphylococcus aureus/physiology
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