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1.
Exp Eye Res ; 236: 109669, 2023 11.
Article in English | MEDLINE | ID: mdl-37774962

ABSTRACT

Therapeutic management of inflammation in infectious keratitis (IK) requires new strategy and targets for selective immunomodulation. Targeting host cell-type specific inflammatory responses might be a viable strategy to curtail unnecessary inflammation and reduce tissue damage without affecting pathogen clearance. This study explores the possibility of pathogen and host cell-type dependent differences in the inflammatory pathways relevant in the pathogenesis of IK. Human corneal epithelial cell line (HCEC) and phorbol 12-myristate-13 acetate (PMA) differentiated THP-1 macrophage line were infected with either Aspergillus flavus conidia or Acanthamoeba castellanii trophozoites and the elicited inflammatory responses were studied in terms of gene expression and secretion of proinflammatory factors interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α) and an upstream inflammatory regulator and mediator protein-the Macrophage Migration Inhibitory Factor (MIF). Given the pleotropic mode of MIF function in diverse cell types relevant in many human diseases, we tested if MIF driven responses to infection is different in HCECs and THP-1 macrophages by studying its expression, secretion and involvement in inflammation by siRNA mediated knockdown. We also examined IK patient tear samples for MIF levels. Infection with A. flavus or A. castellanii induced IL-8 and TNF-α responses in HCECs and THP-1 macrophages but to different levels. Our preliminary human data showed that the level of secreted MIF protein was elevated in IK patient tear, however, MIF secretion by the two cell types were strikingly different in-vitro, under both normal and infected conditions. We found that HCECs released MIF constitutively, which was significantly inhibited with infection, whereas THP-1 macrophages were stimulated to release MIF during infection. MIF gene expression remained largely unaffected by infection in both the cell lines. Although MIF in HCECs appeared to be intracellularly captured during infection, MIF knockdown in HCECs associated with a partial reduction of the IL-8 and TNF-α expression produced by either of the pathogens, suggesting a pro-inflammatory role for MIF in HCECs, independent of its canonical cytokine like function. In contrast, MIF knockdown in THP-1 macrophages accompanied a dramatic increase in IL-8 and TNF-α expression during A. castellanii infection, while the responses to A. flavus infection remained unchanged. These data imply a host cell-type and pathogen specific distinction in the MIF- related inflammatory signaling and MIF as a potential selective immunomodulatory target in infectious keratitis.


Subject(s)
Keratitis , Macrophage Migration-Inhibitory Factors , Humans , Macrophage Migration-Inhibitory Factors/genetics , Tumor Necrosis Factor-alpha , Interleukin-8/genetics , Inflammation , Immunomodulation , Intramolecular Oxidoreductases
2.
Plant Sci ; 324: 111425, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36007630

ABSTRACT

Indian mustard (Brassica juncea) faces significant yield loss due to the 'Black Spot Disease,' caused by a fungus Alternaria brassicicola. In plants, NAC transcription factors (NAC TFs) are known for their roles in development and stress tolerance. One such NAC TF, NAC 62, was induced during A. brassicicola challenge in Sinapis alba, a non-host resistant plant against this fungus. Sequence analyses of BjuNAC62 from B. juncea showed that it belonged to the membrane-bound class of transcription factors. Gene expression study revealed differential protein processing of NAC62 between B. juncea and S. alba on pathogen challenge. Furthermore, NAC62 processing to 25 kDa protein was found to be unique to the resistant plant during pathogenesis. Conditional expression of BjuNAC62ΔC, which lacks its transmembrane domain, in B. juncea showed improved tolerance to A. brassicicola. BjuNAC62ΔC processing to 25 kDa product was also observed in tolerant transgenic plants. Additionally, transgenic plants showed induced expression of genes associated with defense-related phytohormone signaling pathways on pathogen challenge. Again, altered phenotypes suggest a possible developmental effect of BjuNAC62∆C in transgenic plants. The overall results suggest that the processing of BjuNAC62 might be playing a crucial role in resistance response against Black Spot disease by modulating defense-associated genes.


Subject(s)
Mustard Plant , Plant Growth Regulators , Alternaria , Mustard Plant/genetics , Mustard Plant/metabolism , Plant Diseases/genetics , Plant Diseases/microbiology , Plant Growth Regulators/metabolism , Plants, Genetically Modified/genetics , Transcription Factors/genetics , Transcription Factors/metabolism
3.
Microbiol Res ; 263: 127146, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35940108

ABSTRACT

The sensing of environmental conditions such as nutrient availability and the ability to adapt and respond to changing conditions are crucial for the survival of living organisms. Evidence from several organisms have revealed that some metabolic enzymes act as sensors of nutrient status and regulate the expression of sets of genes required for nutrients utilization and condition specific environmental adaptation. Thus metabolic enzymes regulate the signaling pathway by acting as transcriptional regulators and providing required metabolites. The commensal yeast, Candida albicans has recently emerged as a model system for understanding the N-acetylglucosamine (GlcNAc) signaling pathway in eukaryotes. GlcNAc kinase (Hxk1), the first enzyme of the catabolic cascade, has been shown to perform several functions such as regulation of gene expression and regulation of the metabolic status of the cell thereby resulting in a change in cell morphology (yeast-hyphal transition, white-opaque switching), metabolic gene expression, synthesis of metabolic precursors, induction of glycolytic flux rate and biofilm formation. Here, in this review we have discussed various roles of Hxk1that have not been reported in other organisms previously. The enzyme exhibits dynamic changes in subcellular localization consistent with its expanded functions inside the cell. Thus Hxk1 in C. albicans orchestrates several dynamic cellular processes and this signaling system can act as a paradigm to understand the cell fate and metabolic specialization in other eukaryotes too. Still, the molecular cues involved in Hxk1 mediating functions are yet to be unveiled; the relationship between Hxk1 sensing and its signaling effects is also not understood yet.


Subject(s)
Candida albicans , Gene Expression Regulation, Fungal , Acetylglucosamine/genetics , Candida albicans/metabolism , Fungal Proteins/genetics , Fungal Proteins/metabolism , Phosphotransferases (Alcohol Group Acceptor)/genetics , Phosphotransferases (Alcohol Group Acceptor)/metabolism
4.
Biochim Biophys Acta Gen Subj ; 1866(8): 130164, 2022 08.
Article in English | MEDLINE | ID: mdl-35523365

ABSTRACT

BACKGROUND: The cell stress response plays an important role in the survival of organisms. Studies have revealed that the pathogenic yeast Candida albicans that constantly encounters various environmental insults inside the host has emerged as an ideal system to understand the molecular mechanism (s) of stress response. In this study, we characterize a stress-inducible gene SRG1 which is a Halo Acid Dehalogenase (HAD) family member from C. albicans. METHODS: We used confocal microscopy, site-directed mutagenesis, gene deletion techniques, and tandem-affinity purification and co-immunoprecipitation studies to functionally characterize SRG1. RESULTS: The sub-cellular localization of Srg1 is predominantly cytoplasmic and includes punctate mitochondrial staining in the presence of salt. Protein purification studies coupled with LC-MS analysis showed that Srg1 is a phosphoprotein. The Srg1 mutant carrying S47A and S49A mutations failed to migrate to mitochondria in the presence of salt but retained its phosphatase activity. Srg1 migrates to the nucleus in ∆hog1 mutant cells indicating an unorthodox role for HAD family proteins in stress-mediated transcriptional response. Srg1 also interacts with Erg13, a component involved in the mitochondrial membrane lipid biosynthesis pathway. CONCLUSIONS: A multistep relay mechanism that includes a positive modulation by the MAP kinase Hog1 and a negative modulation by the global repressor Tup1 controls SRG1 expression. GENERAL SIGNIFICANCE: Taken together, our work contributes towards gaining a functional insight into a class of phosphatases that probably have evolved with novel specificities in the pathogenic yeast C. albicans to counteract stressful conditions.


Subject(s)
Candida albicans , Phosphoprotein Phosphatases , Candida albicans/genetics , Candida albicans/metabolism , Fungal Proteins/genetics , Fungal Proteins/metabolism , Phosphoprotein Phosphatases/genetics , Phosphoprotein Phosphatases/metabolism , Phosphorylation , Stress, Physiological/genetics
5.
Mol Microbiol ; 117(2): 429-449, 2022 02.
Article in English | MEDLINE | ID: mdl-34877729

ABSTRACT

N-acetylglucosamine (GlcNAc), an important amino sugar at the infection sites of the fungal pathogen Candida albicans, triggers multiple cellular processes. GlcNAc import at the cell surface is mediated by GlcNAc transporter, Ngt1 which seems to play a critical role during GlcNAc signaling. We have investigated the Ngt1 dynamics that provide a platform for further studies aimed at understanding the mechanistic insights of regulating process(es) in C. albicans. The expression of this transporter is prolific and highly sensitive to even very low levels (˂2 µM) of GlcNAc. Under these conditions, Ngt1 undergoes phosphorylation-associated ubiquitylation as a code for internalization. This ubiquitylation process involves the triggering proteins like protein kinase Snf1, arrestin-related trafficking adaptors (ART) protein Rod1, and yeast ubiquitin ligase Rsp5. Interestingly, analysis of ∆snf1 and ∆rsp5 mutants revealed that while Rsp5 is promoting the endosomal trafficking of Ngt1-GFPɤ, Snf1 hinders the process. Furthermore, colocalization experiments of Ngt1 with Vps17 (an endosomal marker), Sec7 (a trans-Golgi marker), and a vacuolar marker revealed the fate of Ngt1 during sugar-responsive endosomal trafficking. ∆ras1 and ∆ubi4 mutants showed decreased ubiquitylation and delayed endocytosis of Ngt1. According to our knowledge, this is the first report which illustrates the mechanistic insights that are responsible for endosomal trafficking of a GlcNAc transporter in an eukaryotic organism.


Subject(s)
Phosphoenolpyruvate Sugar Phosphotransferase System , Acetylglucosamine/metabolism , Candida albicans/genetics , Candida albicans/metabolism , Endocytosis , Endosomal Sorting Complexes Required for Transport/genetics , Endosomal Sorting Complexes Required for Transport/metabolism , Fungal Proteins , Gene Expression Regulation, Fungal , Phosphoenolpyruvate Sugar Phosphotransferase System/metabolism , Sugars/metabolism
6.
Plant Sci ; 309: 110953, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34134846

ABSTRACT

Lysin motif receptor-like kinases (LYKs) are involved in the recognition of chitin and activation of plant immune response. In this study, we found LYK4 to be strongly induced in resistant Sinapis alba compared with susceptible Brassica juncea on challenge with Alternaria brassicicola. In silico analysis and in vitro kinase assay revealed that despite the presence of canonical protein kinase fold, B.juncea LYK4 (BjLYK4) lacks several key residues of a prototype protein kinase which renders it catalytically inactive. Transient expression analysis confirmed that fluorescently tagged BjLYK4 localizes specifically to the plasma membrane. Overexpression (OE) of BjLYK4 in B. juncea enhanced tolerance against A. brassicicola. Interestingly, the OE lines also exhibited a novel trichome dense phenotype and increased jasmonic acid (JA) responsiveness. We further showed that many chitin responsive WRKY transcription factors and JA biosynthetic genes were strongly induced in the OE lines on challenge with the pathogen. Moreover, several JA inducible trichome developmental genes constituting the WD-repeat/bHLH/MYB activator complex were also upregulated in the OE lines compared with vector control and RNA interference line. These results suggest that BjLYK4 plays an essential role in chitin-dependent activation of defense response and chitin independent trichome development likely by influencing the JA signaling pathway.


Subject(s)
Alternaria/physiology , Cyclopentanes/metabolism , Mustard Plant/genetics , Oxylipins/metabolism , Plant Diseases/immunology , Signal Transduction , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Gene Expression , Mustard Plant/enzymology , Plant Diseases/microbiology , Plant Growth Regulators , Transcription Factors/genetics , Transcription Factors/metabolism , Trichomes/genetics , Trichomes/metabolism
7.
J Fungi (Basel) ; 7(1)2021 Jan 19.
Article in English | MEDLINE | ID: mdl-33477740

ABSTRACT

The amino sugar, N-acetylglucosamine (GlcNAc), has emerged as an attractive messenger of signaling in the pathogenic yeast Candida albicans, given its multifaceted role in cellular processes, including GlcNAc scavenging, import and metabolism, morphogenesis (yeast to hyphae and white to opaque switch), virulence, GlcNAc induced cell death (GICD), etc. During signaling, the exogenous GlcNAc appears to adopt a simple mechanism of gene regulation by directly activating Ngs1, a novel GlcNAc sensor and transducer, at the chromatin level, to activate transcriptional response through the promoter acetylation. Ngs1 acts as a master regulator in GlcNAc signaling by regulating GlcNAc catabolic gene expression and filamentation. Ndt80-family transcriptional factor Rep1 appears to be involved in the recruitment of Ngs1 to GlcNAc catabolic gene promoters. For promoting filamentation, GlcNAc adopts a little modified strategy by utilizing a recently evolved transcriptional loop. Here, Biofilm regulator Brg1 takes up the key role, getting up-regulated by Ngs1, and simultaneously induces Hyphal Specific Genes (HSGs) expression by down-regulating NRG1 expression. GlcNAc kinase Hxk1 appears to play a prominent role in signaling. Recent developments in GlcNAc signaling have made C. albicans a model system to understand its role in other eukaryotes as well. The knowledge thus gained would assist in designing therapeutic interventions for the control of candidiasis and other fungal diseases.

8.
Cartilage ; 12(2): 162-168, 2021 04.
Article in English | MEDLINE | ID: mdl-30674199

ABSTRACT

OBJECTIVE: The purpose of this study was to retrospectively assess the frequency and characteristics of acetabular cartilage delamination (CD) in femoroacetabular impingement (FAI) patients and to assess the sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of magnetic resonance arthrography (MRA) in detecting CD based on the radiologist report. DESIGN: This is a single-center retrospective review of consecutive patients operated for symptomatic FAI. All of the patients had a 1.5-T MR-arthrogram within 12 months preoperatively. MRA reports of these patients were compared with operation notes and surgical videos of all patients by two trained assessors. RESULTS: At surgery, CD of the acetabulum was present in 169 patients out of a total of 229 patients (74%). Only 6.5% (11 patients) of CD was described on the MRA reports preoperatively. The mean age of the patients was 37.6 ± 13.3 years. The average extent of delamination was 3.12 ± 1.5 cm2 with a mean coronal × sagittal extent of 0.68 × 4.33 cm. There was a significant difference regarding age (P = 0.002), alpha angle from frog view (P = 0.002), and alpha angle from anteroposterior view (P = 0.012) between the patients with delamination and without delamination. The majority of labral tears and cartilage damage were located in the anterosuperior quadrant. MRA sensitivity was 6%, specificity 98%, NPV 27%, and PPV 91% based on the radiologist report. CONCLUSION: The CD in patients with FAI can be severely underdiagnosed with MRA. There is a need for better standard diagnostic criteria to detect CD in patients with FAI.


Subject(s)
Acetabulum/diagnostic imaging , Arthrography/statistics & numerical data , Cartilage Diseases/diagnostic imaging , Femoracetabular Impingement/diagnostic imaging , Magnetic Resonance Imaging/statistics & numerical data , Acetabulum/injuries , Adult , Arthrography/methods , Cartilage Diseases/complications , Cartilage, Articular/diagnostic imaging , Cartilage, Articular/injuries , Female , Femoracetabular Impingement/complications , Follow-Up Studies , Humans , Magnetic Resonance Imaging/methods , Male , Predictive Value of Tests , Reproducibility of Results , Retrospective Studies , Sensitivity and Specificity
9.
PLoS Pathog ; 16(9): e1008952, 2020 09.
Article in English | MEDLINE | ID: mdl-32960936

ABSTRACT

Understanding how the protozoan protein degradation pathway is regulated could uncover new parasite biology for drug discovery. We found the COP9 signalosome (CSN) conserved in multiple pathogens such as Leishmania, Trypanosoma, Toxoplasma, and used the severe diarrhea-causing Entamoeba histolytica to study its function in medically significant protozoa. We show that CSN is an essential upstream regulator of parasite protein degradation. Genetic disruption of E. histolytica CSN by two distinct approaches inhibited cell proliferation and viability. Both CSN5 knockdown and dominant negative mutation trapped cullin in a neddylated state, disrupting UPS activity and protein degradation. In addition, zinc ditiocarb (ZnDTC), a main metabolite of the inexpensive FDA-approved globally-available drug disulfiram, was active against parasites acting in a COP9-dependent manner. ZnDTC, given as disulfiram-zinc, had oral efficacy in clearing parasites in vivo. Our findings provide insights into the regulation of parasite protein degradation, and supports the significant therapeutic potential of COP9 inhibition.


Subject(s)
COP9 Signalosome Complex/metabolism , Entamoeba histolytica/metabolism , Proteolysis , Animals , COP9 Signalosome Complex/genetics , Disulfiram/pharmacology , Ditiocarb/pharmacology , Entamoeba histolytica/genetics , Mice , Protozoan Proteins/genetics
10.
Front Immunol ; 11: 1273, 2020.
Article in English | MEDLINE | ID: mdl-32655566

ABSTRACT

Wound healing after an injury is essential for life. An in-depth understanding of the healing process is necessary to ultimately improve the currently limited treatment options for patients suffering as a result of damage to various organs and tissues. Injuries, even the most minor, trigger an inflammatory response that protects the host and activates repair pathways. In recent years, substantial progress has been made in delineating the mechanisms by which inflammatory cytokines and their receptors facilitate tissue repair and regeneration. This mini review focuses on emerging literature on the role of the cytokine macrophage migration inhibitory factor (MIF) and its cell membrane receptor CD74, in protecting against injury and promoting healing in different parts of the body.


Subject(s)
Antigens, Differentiation, B-Lymphocyte/immunology , Histocompatibility Antigens Class II/immunology , Macrophage Migration-Inhibitory Factors/immunology , Wound Healing/immunology , Animals , Antigens, Differentiation, B-Lymphocyte/metabolism , Histocompatibility Antigens Class II/metabolism , Humans , Macrophage Migration-Inhibitory Factors/metabolism , Regeneration/immunology , Signal Transduction/physiology
11.
Mediators Inflamm ; 2020: 3645157, 2020.
Article in English | MEDLINE | ID: mdl-32148437

ABSTRACT

Myasthenia gravis (MG) is a CD4+ T cell-dependent autoimmune disease resulting from aberrant immune response mediated by circulating autoantibodies at the neuromuscular junction. Intravenous immunoglobulin (IVIg) is an expensive and commonly used immunotherapeutic approach to treat patients with MG. The mechanisms of actions involved in IVIg treatment, however, remain to be investigated. In an effort to examine the roles of various subsets of CD4+ T cells in the periphery blood of MG and uncover the mechanisms that contribute to the therapeutical effects of IVIg, we first demonstrated that a subset of CD4+ T cells, CTLA-4-expressing regulatory T (Treg) cells, were underrepresented and functionally defective in MG patients. The dynamic profiling during the IVIg therapy course further revealed an inverse relationship between the frequency of CTLA-4+ Treg and the quantitative MG (QMG) score that represents disease severity. Our mechanistic studies indicated that IVIg expands CTLA-4-Treg cells via modulating antigen-presenting dendritic cells (DCs). To determine the molecular defects of CTLA-4 in abnormities of Treg in MG patients, we demonstrated hypermethylation at -658 and -793 CpGs of CTLA-4 promoter in MG Tregs. Interestingly, IVIg therapy significantly reduced the methylation level at these two sites in MG patients. Overall, our study may suggest a role of CTLA-4 in functionally defected Treg cells in MG and its actions involved in IVIg therapy.


Subject(s)
CTLA-4 Antigen/metabolism , Myasthenia Gravis/metabolism , T-Lymphocytes, Regulatory/metabolism , T-Lymphocytes/metabolism , Adult , CD4-Positive T-Lymphocytes/metabolism , Dendritic Cells/metabolism , Enzyme-Linked Immunosorbent Assay , Female , Flow Cytometry , Humans , Immunoglobulins, Intravenous , Lipopolysaccharide Receptors/metabolism , Male , Middle Aged , Myasthenia Gravis/immunology , Real-Time Polymerase Chain Reaction
12.
Cell Mol Gastroenterol Hepatol ; 10(1): 101-112, 2020.
Article in English | MEDLINE | ID: mdl-32004754

ABSTRACT

BACKGROUND & AIMS: The inflammatory response to intestinal damage promotes healing through mechanisms that are incompletely understood. Gene expression of cluster of differentiation 74 (CD74), the receptor for cytokine macrophage migration inhibitory factor, is increased in patients with inflammatory bowel disease (IBD), however, the role of CD74 signaling in intestinal inflammation remains poorly understood. The aim of this study was to determine the functional role of CD74 signaling in intestinal inflammation. METHODS: We studied the characteristics of CD74 protein expression in human IBD and experimental colitis. The functional role of CD74 signaling in the intestine was investigated using cellular models; wild-type, CD74-/-, and bone marrow chimera mice; neutralizing anti-CD74 antibodies; flow cytometry; immunohistochemistry; immunofluorescence; immunoblotting; and clustered regularly interspaced short palindromic repeats and associated protein 9 technology. RESULTS: In IBD patients and experimental colitis, CD74-receptor protein expression was increased in inflamed intestinal tissue, prominently in the crypt epithelial cells. By using distinct but complementary chemical and non-chemically induced mouse models of colitis with genetic and antibody neutralization approaches, we found that CD74 signaling was necessary for gut repair. Mechanistically, we found that the macrophage migration inhibitory factor cytokine, which also is increased in colitis, stimulated the CD74 receptor, enhancing intestinal epithelial cell proliferation through activation of the protein kinase B and the extracellular signal-regulated kinase pathways. Our data also suggest that CD74 signaling in immune cells was not essential for mucosal healing. CONCLUSIONS: CD74 signaling is strongly activated during intestinal inflammation and protects the host by promoting epithelial cell regeneration, healing, and maintaining mucosal barrier integrity. Enhancing the CD74 pathway may represent a unique therapeutic strategy for promoting healing in IBD.


Subject(s)
Antigens, Differentiation, B-Lymphocyte/metabolism , Colitis, Ulcerative/immunology , Crohn Disease/immunology , Histocompatibility Antigens Class II/metabolism , Intestinal Mucosa/pathology , Signal Transduction/immunology , Animals , Antigens, Differentiation, B-Lymphocyte/genetics , Biopsy , Bone Marrow Transplantation , Cell Line, Tumor , Colitis, Ulcerative/genetics , Colitis, Ulcerative/parasitology , Colitis, Ulcerative/pathology , Crohn Disease/pathology , Datasets as Topic , Disease Models, Animal , Entamoeba histolytica/pathogenicity , Epithelial Cells/immunology , Epithelial Cells/pathology , Gene Expression Profiling , Histocompatibility Antigens Class II/genetics , Humans , Intestinal Mucosa/cytology , Intestinal Mucosa/immunology , Intramolecular Oxidoreductases/metabolism , Macrophage Migration-Inhibitory Factors/metabolism , Mice , Mice, Knockout , Permeability , Primary Cell Culture , Regeneration/immunology , Signal Transduction/genetics , Transplantation Chimera
13.
J Infect Dis ; 221(7): 1185-1193, 2020 03 16.
Article in English | MEDLINE | ID: mdl-31677380

ABSTRACT

Targeting virulence factors represents a promising alternative approach to antimicrobial therapy, through the inhibition of pathogenic pathways that result in host tissue damage. Yet, virulence inhibition remains an understudied area in parasitology. Several medically important protozoan parasites such as Plasmodium, Entamoeba, Toxoplasma, and Leishmania secrete an inflammatory macrophage migration inhibitory factor (MIF) cytokine homolog, a virulence factor linked to severe disease. The aim of this study was to investigate the effectiveness of targeting parasite-produced MIF as combination therapy with standard antibiotics to reduce disease severity. Here, we used Entamoeba histolytica as the model MIF-secreting protozoan, and a mouse model that mirrors severe human infection. We found that intestinal inflammation and tissue damage were significantly reduced in mice treated with metronidazole when combined with anti-E. histolytica MIF antibodies, compared to metronidazole alone. Thus, this preclinical study provides proof-of-concept that combining antiparasite MIF-blocking antibodies with current standard-of-care antibiotics might improve outcomes in severe protozoan infections.


Subject(s)
Antibodies, Protozoan/immunology , Antiprotozoal Agents , Host-Parasite Interactions/drug effects , Macrophage Migration-Inhibitory Factors/metabolism , Protozoan Proteins/metabolism , Animals , Antiprotozoal Agents/immunology , Antiprotozoal Agents/pharmacology , Entamoeba histolytica/drug effects , Entamoeba histolytica/immunology , Entamoeba histolytica/metabolism , Entamoeba histolytica/pathogenicity , Entamoebiasis , HCT116 Cells , Humans , Mice , Models, Molecular
14.
Front Immunol ; 10: 1995, 2019.
Article in English | MEDLINE | ID: mdl-31497025

ABSTRACT

Protozoan parasites represent a major threat to health and contribute significantly to morbidity and mortality worldwide, especially in developing countries. This is further compounded by lack of effective vaccines, drug resistance and toxicity associated with current therapies. Multiple protozoans, including Plasmodium, Entamoeba, Toxoplasma, and Leishmania produce homologs of the cytokine MIF. These parasite MIF homologs are capable of altering the host immune response during infection, and play a role in immune evasion, invasion and pathogenesis. This minireview outlines well-established and emerging literature on the role of parasite MIF homologs in disease, and their potential as targets for therapeutic and preventive interventions.


Subject(s)
Immune Evasion , Macrophage Migration-Inhibitory Factors/immunology , Parasites/immunology , Parasites/pathogenicity , Animals , Humans
15.
Mol Plant Microbe Interact ; 32(10): 1429-1447, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31184524

ABSTRACT

Concomitant increase of auxin-responsive factors ARF16 and ARF17, along with enhanced expression of ARF10 in resistant Sinapis alba compared with that in susceptible Brassica juncea upon challenge with Alternaria brassicicola, revealed that abscisic acid (ABA)-auxin crosstalk is a critical factor for resistance response. Here, we induced the ABA response through conditional expression of ARF10 in B. juncea using the A. brassicicola-inducible GH3.3 promoter. Induced ABA sensitivity caused by conditional expression of ARF10 in transgenic B. juncea resulted in tolerance against A. brassicicola and led to enhanced expression of several ABA-responsive genes without affecting the auxin biosynthetic gene expression. Compared with ABI3 and ABI4, ABI5 showed maximum upregulation in the most tolerant transgenic lines upon pathogen challenge. Moreover, elevated expression of ARF10 by different means revealed a direct correlation between ARF10 expression and the induction of ABI5 protein in B. juncea. Through in vitro DNA-protein experiments and chromosome immunoprecipitation using the ARF10 antibody, we demonstrated that ARF10 interacts with the auxin-responsive elements of the ABI5 promoter. This suggests that ARF10 may function as a modulator of ABI5 to induce ABA sensitivity and mediate the resistance response against A. brassicicola.


Subject(s)
Abscisic Acid , Alternaria , Arabidopsis Proteins , Gene Expression Regulation, Plant , Mustard Plant , Transcription Factors , Alternaria/physiology , Indoleacetic Acids/metabolism , Mustard Plant/genetics , Mustard Plant/microbiology , Transcription Factors/genetics
16.
Curr Clin Microbiol Rep ; 6(1): 51-57, 2019.
Article in English | MEDLINE | ID: mdl-31008019

ABSTRACT

PURPOSE OF REVIEW: Entamoeba histolytica is a protozoan parasite that causes amebiasis, which remains a significant cause of morbidity and mortality worldwide. E. histolytica causes tissue destruction which leads to clinical disease. This review outlines some of the recent advances that have furthered our understanding of the processes that lead to the tissue damage caused by E. histolytica. RECENT FINDINGS: Recent studies have identified new mechanisms involved in E. histolytica-induced tissue damage. These include (i) new form of contact-dependent killing called trogocytosis; (ii) parasite-produced cytokine, macrophage migration inhibitory factor, that contributes to inflammation; (iii) exploitation of host immune response to promote invasion; and (iv) the contribution of the gut microbiome to clinical disease. SUMMARY: Targeting these mechanisms that result in tissue injury should be a focus of future research for the development of improved preventive and therapeutic strategies for amebiasis.

17.
Prim Health Care Res Dev ; 20: e18, 2018 Dec 27.
Article in English | MEDLINE | ID: mdl-30587261

ABSTRACT

Shorter length of stay for postpartum mothers and their newborns necessitates careful community follow-up after hospital discharge. The vast amount of information given during the initial postpartum period can be overwhelming. New parents often need considerable support to understand the nuances of newborn care including newborn feeding. Primary health care and community services need to ensure there is a seamless continuum of care to support, empower, and educate new mothers and their families to prevent unnecessary hospital readmission and other negative health outcomes. The Healthy & Home postpartum community nursing program provides clinical communication and supports to bridge the gap between acute hospital and community follow-up care through home visits, a primary health care clinic, a breastfeeding center, a breastfeeding café, a postpartum anxiety and depression support group, bereavement support, and involvement in a Baby-Friendly Initiative™ coalition. Nurses working in the program have the acute care skills and resources to complete required health care assessments and screening tests. They are also international board-certified lactation consultants able to provide expert breastfeeding and lactation care. This paper describes how the Healthy & Home program has evolved over the past 25 years and offers suggestions to other organizations wanting to develop a postpartum program to meet the physical and mental health needs of postpartum families to promote maternal and infant wellbeing.

18.
Orthop J Sports Med ; 6(11): 2325967118807906, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30480021

ABSTRACT

BACKGROUND: Anatomic glenoid reconstruction involves the use of distal tibial allograft for bony augmentation of the glenoid surface. An all-arthroscopic approach was recently described to avoid damage to the subscapularis tendon and preserve the capsule and labrum. PURPOSE: To explore and compare change in surgical time between 2 proposed methods used for the treatment of anterior shoulder instability-arthroscopic anatomic glenoid reconstruction (AAGR) and arthroscopic Latarjet (AL)-over successive procedures. We also compared graft positioning on the anterior glenoid surface between the 2 methods. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: This was a single-surgeon retrospective review of 54 cases of surgically treated recurrent anterior shoulder instability: 27 had AAGR with distal tibial allograft, while the other 27 had AL. AAGR with the distal tibial allograft was the primary choice for the treatment of anterior shoulder instability; however, AL was performed when tibial allograft was not available from the bone bank. Thus, there was an overlapping period for those 2 procedures. Procedure start and end times were recorded, and duration was calculated. Postoperative 3-dimensional computed tomography scans were reviewed, and graft position was judged to be in the lower third (desired position), middle third, or upper third of the anterior glenoid surface. To assess learning, these data were organized in chronological order of surgery, and each surgical cohort was divided into 3 chronological clusters of 9 patients each. Learning was assessed through change in operative time over successive clusters, change in variability of operative time among clusters, and change in graft positioning among clusters. Statistical analysis comprised a 2-tailed independent-sample t test and the Levene test for equality of variance. RESULTS: Our study found that AAGR was significantly faster to perform than AL in the early (P = .001), middle (P = .001), and late (P = .05) clusters of each cohort. Duration of surgery did not significantly improve across clusters within each cohort (P = .15-.79). There were no significant changes in the variability of surgical time in the AAGR group (P = .09) or the AL group (P = .13). Desired positioning of the bone graft on the anterior glenoid surface (lower third) was identified more commonly in the AAGR cohort. CONCLUSION: AAGR is faster to learn and perform than AL for the treatment of recurrent anterior shoulder instability with significant glenoid bone loss. The current study found higher rates of desired graft positioning for AAGR clusters.

19.
Sci Rep ; 8(1): 10241, 2018 07 06.
Article in English | MEDLINE | ID: mdl-29980718

ABSTRACT

Multiple protozoans produce homologs of the cytokine MIF which play a role in immune evasion, invasion and pathogenesis. However, how parasite-encoded MIF activity is controlled remains poorly understood. Cytokine activity can be inhibited by intracellular binding partners that are released in the extracellular space during cell death. We investigated the presence of an endogenous parasite protein that was capable of interacting and interfering with MIF activity. A screen for protein-protein interaction was performed using immunoaffinity purification of amebic cell lysate with specific anti-Entamoeba histolytica MIF (EhMIF) antibody followed by mass spectrometry analysis, which revealed an E. histolytica-produced JAB1 protein (EhJAB1) as a potential binding partner. JAB1 was found to be highly conserved in protozoans. Direct interaction between the EhMIF and EhJAB1 was confirmed by several independent approaches with GST pull-down, co-immunoprecipitation, and Biolayer interferometry (BLI) assays. Furthermore, the C-terminal region outside the functional JAMM deneddylase motif was required for EhMIF binding, which was consistent with the top in silico predictions. In addition, EhJAB1 binding blocked EhMIF-induced IL-8 production by human epithelial cells. We report the initial characterization of a parasite-encoded JAB1 and uncover a new binding partner for a protozoan-produced MIF protein, acting as a possible negative regulator of EhMIF.


Subject(s)
Antibodies/immunology , Entamoeba histolytica/physiology , Entamoebiasis/metabolism , Inflammation/prevention & control , Macrophage Migration-Inhibitory Factors/metabolism , Protozoan Proteins/metabolism , Amino Acid Sequence , Cytokines/metabolism , Entamoebiasis/immunology , Entamoebiasis/parasitology , HCT116 Cells , Humans , Inflammation/immunology , Inflammation/metabolism , Inflammation/parasitology , Macrophage Migration-Inhibitory Factors/immunology , Protein Interaction Domains and Motifs , Protozoan Proteins/immunology
20.
Global Health ; 14(1): 47, 2018 05 09.
Article in English | MEDLINE | ID: mdl-29743085

ABSTRACT

BACKGROUND: Neonatal mortality is declining slowly compared to under-five mortality in many developing countries including Afghanistan. About three-fourths of these deaths occur in the early neonatal period (i.e., the first week of life). Although a number of studies investigated determinants of early neonatal mortality in other countries, there is a lack of evidence regarding this in Afghanistan. This study investigated determinants of early neonatal mortality in Afghanistan. METHODS: Data from the Afghanistan Demographic and Health Survey 2015 (AfDHS 2015) were analyzed. After reporting the weighted frequency distributions of selected factors, a multilevel logistic regression model revealed adjusted associations of factors with early neonatal mortality. RESULTS: A total of 19,801 weighted live-births were included in our analysis; 266 (1.4%) of the newborns died in this period. Multivariable analysis found that multiple gestations (adjusted odds ratio (AOR): 9.3; 95% confidence interval (CI): 5.7-15.0), larger (AOR: 2.9; 95% CI: 2.2-3.8) and smaller (AOR: 1.8; 95% CI: 1.2-2.6) than average birth size, maternal age ≤ 18 years (AOR: 1.8; 95% CI: 1.1-3.2) and ≥ 35 years (AOR: 1.7; 95% CI: 1.3-2.3), and birth interval of < 2 years (AOR: 2.6; 95% CI: 1.4-4.9) had higher odds of early neonatal mortality. On the other hand, antenatal care by a skilled provider (AOR: 0.7; 95% CI: 0.5-0.9), facility delivery (AOR: 0.7; 955 CI: 0.5-0.9), paternal higher education level (AOR: 0.7; 95% CI: 0.5-1.0), living in north-western (AOR: 0.3; 95% CI: 0.1-0.6), central-western regions (AOR: 0.5; 95% CI: 0.3-0.9) and in a community with higher maternal education level (AOR: 0.4; 95% CI: 0.2-0.9) had negative association. CONCLUSIONS: Several individual, maternal and community level factors influence early neonatal deaths in Afghanistan; significance of the elements of multiple levels indicates that neonatal survival programs should follow a multifaceted approach to incorporate these associated factors. Programs should focus on birth interval prolongation with the promotion of family planning services, utilization of antenatal care and institutional delivery services along with management of preterm and sick infants to prevent this large number of deaths in this period.


Subject(s)
Infant Mortality , Adolescent , Adult , Afghanistan/epidemiology , Demography , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Risk Factors , Young Adult
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