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1.
Infect Immun ; 2021 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-33593890

RESUMEN

Haemaphysalis longicornis is a blood-feeding hard tick known for transmitting a variety of pathogens, including Babesia How the parasites in the imbibed blood become anchored in the midgut of ticks is still unknown. Leucine-rich repeat domain (LRR)-containing protein, which is associated with the innate immune reaction and conserved in many species, has been detected in H. longicornis and has previously been indicated in inhibiting the growth of Babesia gibsoni However, the detailed mechanism is unknown. In this study, one of the ligands for LRR from H. longicornis (HlLRR) was identified in B. microti, designated as BmActin (Babesia microti actin), using GST pull-down experiments and immunofluorescence assay. Moreover, RNA interference of HlLRR led to a decrease in the BmActin mRNA expression in the midgut of fully engorged ticks, which fed on B. microti-infected mice. We also found that the expression level of the innate immune molecules in H. longicornis, defensin, antimicrobial peptides (AMPs), and lysozyme were downregulated after the knockdown of HlLRR. However, subolesin expression was upregulated. These results indicate that HlLRR not only recognizes BmActin but may also modulate innate immunity in ticks to influence Babesia growth, which will further benefit the development of anti-Babesia vaccines or drugs.

2.
Exp Eye Res ; 205: 108488, 2021 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-33571532

RESUMEN

Increased intraocular pressure (IOP) is the main risk factor for primary open-angle glaucoma and results from impaired drainage of aqueous humor (AH) through the trabecular outflow pathway. AH must pass the inner wall (IW) endothelium of Schlemm's canal (SC), which is a monolayer held together by tight junctions, to exit the eye. One route across the IW is through giant vacuoles (GVs) with their basal openings and intracellular pores (I-pores). AH drainage through the trabecular outflow pathway is segmental. Whether more GVs with both basal openings and I-pores are present in the active flow areas and factors that may influence formation of GVs with I-pores have not been fully elucidated due to limitations in imaging methods. In this study, we applied a relatively new technique, serial block-face scanning electron microscopy (SBF-SEM), to investigate morphological factors associated with GVs with I-pores in different flow areas. Two normal human donor eyes were perfused at 15 mmHg with fluorescent tracers to label the outflow pattern followed by perfusion-fixation. Six radial wedges of trabecular meshwork including SC (2 each from high-, low-, and non-flow areas) were imaged using SBF-SEM (total: 9802 images). Total GVs, I-pores, basal openings, and four types of GVs were identified. Percentages of GVs with I-pores and basal openings and number of I-pores/GV were determined. Overall, 14.4% (477/3302) of GVs had I-pores. Overall percentage of GVs with both I-pores and basal openings was higher in high- (15.7%), than low- (12.6%) or non-flow (7.3%) areas. Of GVs with I-pores, 83.2% had a single I-pore; 16.8% had multiple I-pores (range: 2-6). Additionally, 180 GVs (90 with I-pores and 90 without I-pores) were randomly selected, manually segmented, and three-dimensionally (3D) reconstructed to determine size, shape, and thickness of the cellular lining. Size of GVs (including median volume, surface area, and maximal cross-sectional area) with I-pores (n = 90) was significantly larger than GVs without I-pores (n = 90) using 3D-reconstructed GVs (P ≤ 0.01). Most I-pores (73.3%; 66/90) were located on or close to GV's maximal cross-sectional area with significant thinning of the cellular lining. Our results suggest that larger size and thinner cellular lining of GVs may contribute to formation of GVs with I-pores. More GVs with I-pores and basal openings were observed in high-flow areas, suggesting these GVs do provide a channel through which AH passes into SC and that increasing this type of GV may be a potential strategy to increase aqueous outflow for glaucoma treatment.

3.
Ticks Tick Borne Dis ; 12(2): 101623, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33418338

RESUMEN

Babesia microti is a zoonotic pathogen that mainly parasitizes mammalian erythrocytes. Oxidative stress can induce gene mutation, protein denaturation and lipid peroxidation, such as reactive oxygen species (ROS) induced by hypoxic environment and the host immune system. An antioxidase, B. microti thioredoxin reductase (Bmi TrxR), has been identified in B. microti. We used a combination of homology modeling and domain prediction to explore the functional sites of Bmi TrxR and found that TrxR has three domains. Constructed a mutant pool which His-tag were at the N-terminus (TrxR-Nhis, C105-Nhis, C110-Nhis, C105110-Nhis, C547-Nhis, C552-Nhis, C547552-Nhis) and the His tag were at the N- and C-terminus (TrxR-NChis, C547-NChis, C552-NChis, C547552-NChis). The proteins were expressed as His-tagged fusion proteins in Escherichia coli. The His-tag of TrxR C-terminus were affected the reaction with Trx. The inhibitory efficiency of DNCB was decreased for mutant C547, compared with recombinant TrxR, indicating that the action site of DNCB might be cysteine at position 547. These results indicate that the N-terminal active site of Bmi TrxR plays an important role in accepting electrons and promotes electron transfer. The C-terminus His tag of Bmi TrxR affected the electron transfer and the reducing activity of Bmi TrxR. Reduce reactive oxygen produced in oxidative stress was reduced by Bmi TrxR, which is beneficial to Babesia survival. Therefore, reduction site of TrxR may become a potential target for Babesia microti treatment.

4.
Eur J Radiol ; 135: 109512, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33429302

RESUMEN

PURPOSE: To develop a combined nomogram by incorporating the Memorial Sloan Kettering Cancer Center (MSKCC) nomogram and ultrasound (US)-based radiomics score (Radscore) for predicting sentinel lymph node (SLN) metastasis in invasive breast cancer. MATERIALS AND METHODS: This retrospective study was approved by the ethics committee of our institution, and written informed consent was waived. A total of 452 patients with invasive breast cancer who received SLN Biopsy in a single center were included between January 2016 and December 2019. The patients were divided into a training set (n = 318) and a validation set (n = 134). A total of 1216 features were extracted from the regions of interest (ROIs) of the tumors on conventional ultrasound. The maximum relevance minimum redundancy (mRMR) and the least absolute shrinkage and selection operator (LASSO) algorithm were used to build the Radscore. Afterward, the diagnostic performance was assessed and validated. Comparison of receiver operating characteristic (ROC) curves and decision curve analysis (DCA) were performed to evaluate the incremental value of the combined model. RESULTS: Obtained from 18 features, the Radscore indicated a favorable discriminatory capability in the training set with an area under the curve (AUC) of 0.834, whereas a value of 0.770 was observed in the validation set. The AUC of the combined model was 0.901 (95 % confidence interval (95 % CI): 0.865-0.938) in the training set and 0.833 (95 % CI: 0.788-0.878) in the validation set. Both of them were superior to MSKCC or imaging Radscore alone (P < 0.05). DCA demonstrated that the combined model was superior to the others in terms of clinical practicability. CONCLUSION: Preoperative US-based Radscore can improve the accuracy of clinical MSKCC nomogram for SLN metastasis prediction in breast cancer.

5.
Biomed Pharmacother ; 134: 111149, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33385683

RESUMEN

E. coli is associated with high rates of infection and resistance to drugs not only in China but also the rest of the world. In addition, the number of E. coli biofilm infections continue to increase with time. Notably, biofilms are attractive targets for the prevention of infections caused by multidrug-resistant bacteria. Moreover, the pgaABCD-encoded Poly-ß-1,6-N-acetyl-d-glucosamine (PNAG) plays an important role in biofilm formation. Therefore, this study aimed to explore the specific effect of the (R)-(+)-pulegone (PU) on growth and biofilm formation in multi-drug resistant E. coli. The molecular mechanisms involved were also examined. The results showed that PU had significant antibacterial and antibiofilm formation activity against E. coli K1, with MIC and MBC values of 23.68 and 47.35 mg/mL, respectively. On the other hand, the maximum inhibition rate for biofilm formation in the bacterium was 52.36 % at 94.70 mg/mL of PU. qRT-PCR data showed that PU significantly down-regulated expression of the pgaABCD genes (P < 0.05). PU was also broadly effective against biofilm formation in MG1655 and MG1655/ΔpgaABCD, exhibiting the maximum inhibition rates were 98.23 % and 93.35 %, respectively. In addition, PU destroyed pre-formed mature biofilm in both MG1655 and MG1655/ΔpgaABCD about 95.03 % and 92.4 %, respectively. The study therefore verified that pgaA was a potential and key target for PU in E. coli although it was not the only one. Overall, the findings indicated that PU is a potential and novel inhibitor of drug resistance, This therefore gives insights on new ways of preventing and treating biofilm-associated infections in the food industry as well as in clinical practice.

6.
Parasitol Int ; 80: 102223, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33137497

RESUMEN

To better understand the molecular mechanisms underlying allergens and parasite immunity and discover the stage-enriched gene expression of fish-borne zoonotic nematodes in the stomach, we used RNA-seq to study the transcriptome profiles of Anisakis pegreffii (Nematoda: Anisakidae, AP) in simulated gastric juice. Mobile L3 larvae were incubated in simulated medium at 37 °C in 5% CO2 (AP-GJ) and the control group larvae were collected in PBS under the same conditions (AP-PBS). We found that the sequences of A. pegreffii were highly similar to Toxocara canis sequences. Among the transcripts, there would be 138 up-regulated putative genes and 251 down-regulated putative genes in AP-GJ group. Several lipid binging-related genes were more highly expressed in AP-GJ larvae. Moreover, 17 allergen genes were up-regulated and 29 were down-regulated in AP-GJ larvae. Eleven allergen genes belonged to one or more of the following three categories: biological process, cellular component, and molecular function. According to KEGG analysis, the main pathways that were represented included protein processing in transcription, immune system, cancer, and infectious disease. In particular, the most significant changes in the expression of parasite-derived allergen products occurred in AP-GJ larvae. This study helps us to extend our understanding of the biology of the fish-borne zoonotic parasite A. pegreffii and could be helpful for more precise risk assessment and providing guidelines for allergic consumers.

7.
Infect Genet Evol ; 85: 104559, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32961363

RESUMEN

Enterocytozoon bieneusi is reported to be a common microsporidian of humans and animals in various countries. However, scarce information on E. bieneusi has been recorded in farmed goats and sheep in China. As such, we undertook molecular epidemiological investigation of E. bieneusi in farmed goats (Capra aegagrus hircus) and sheep (Ovis aries) in Ningxia, China. A total of 660 genomic DNAs were extracted from individual faecal samples from famed goats (n = 300) and sheep (n = 360), and then tested using a nested PCR-based sequencing approach employing internal transcribed spacer (ITS) of nuclear ribosomal DNA as the genetic marker. Enterocytozoon bieneusi was detected in 237 of all 660 (36%) faecal samples from goats (n = 89) and sheep (n = 148). Correlation analyses revealed that E. bieneusi positive rates were significantly associated with age-groups, seasons and locations (P < 0.05). The analysis of ITS sequence data revealed the presentation of eight known genotypes (BEB6, CD6, CHG1, CHG3, CHG5, CHS8, CM7 and SX1). Phylogenetic analysis of ITS sequence data sets showed that they clustered within Group 2, showing zoonotic potential. These findings suggested that goats and sheep in Ningxia harbor zoonotic genotypes of E. bieneusi and may have a significant risk for zoonotic transmission. Further insight into the epidemiology of E. bieneusi in farmed animals, water and the environment from other areas in China will be important to have an informed position on the public health significance of microsporidiosis caused by this microbe.

8.
Br J Radiol ; : 20200874, 2020 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-32976019

RESUMEN

OBJECTIVE: To evaluate the diagnostic performance of contrast-enhanced ultrasound (CEUS) combined with conventional ultrasound (US) of axillary lymph nodes (ALNs) in predicting metastatic ALNs in patients with breast cancer. METHODS: This retrospective study included 259 patients with breast cancer who underwent conventional US and CEUS. The parameters and patterns evaluated on conventional US included short axis diameter (S), long axis/short axis (L/S) ratio, cortical thickness, resistive index (RI), lymph node (LN) morphology of grey-scale US, hilum and vascular pattern. Meanwhile, enhancement pattern, wash-in time, time to peak (TP), maximum signal intensity, and duration of contrast enhancement were evaluated on CEUS. Univariate and multiple logistic regression analyses were performed to identify independent factors of ALN status. Three models (conventional US, CEUS, and combined parameters) were established. Receiver operating characteristic (ROC) curves were applied to evaluate the accuracy of the three predictive models. RESULTS: On conventional axillary US, LN morphology and vascular pattern were independent factors in predicting metastatic ALNs. On CEUS, maximum signal intensity, duration of contrast enhancement, and TP were independent factors in predicting metastatic ALNs. When combining conventional US and CEUS features, five independent factors obtained from the conventional US and CEUS were associated with ALN status. ROC curve analysis showed that the use of CEUS markers combined with conventional US features (AUC = 0.965) was superior to the use of CEUS markers (AUC = 0.936) and conventional US features alone (AUC = 0.851). CONCLUSION: Combining conventional US and CEUS features can enable discrimination of ALN status better than the use of CEUS and conventional US features alone. ADVANCES IN KNOWLEDGE: The axillary lymph node status in breast cancer patients impacts the treatment decision. Our ultrasonic data demonstrated that CEUS features of ALNs in breast cancer patients could be image markers for predicting ALN status. Combining conventional US and CEUS features of ALNs can improve specificity discrimination of ALN status better than the use of CEUS and the conventional US features alone, which will help the treatment planning optimization.

9.
Parasitol Res ; 119(9): 3013-3022, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32740752

RESUMEN

Babesiosis is a tick-borne protozoonosis caused by Babesia, which can cause fever, hemolytic anemia, hemoglobinuria, and even death. Babesia microti is a parasite found in rodents and can be pathogenic to humans. In this study, the full-length cDNA of a B. microti cysteine protease (BmCYP) was expressed and the recombinant rBmCYP protein analyzed and characterized. BmCYP is encoded by an ORF of 1.3 kb, with a predicted molecular weight of 50 kDa and a theoretical pI of 8.5. The amino acid sequence of BmCYP exhibits an identity of 32.9 to 35.2% with cysteine proteases of Babesia ovis, Babesia bovis, and Theileria, respectively. The results of the proteinase assays show that rBmCYP has cysteine protease enzymatic activity. In addition, we demonstrate that tick cystatins rRhcyst-1 and rRhcyst-2 were able to effectively inhibit the activity of rBmCYP; the inhibition rates were 57.2% and 30.9%, respectively. Tick cystatins Rhcyst-1 and Rhcyst-2 were differentially expressed in ticks that fed on Babesia-infected mice relative to non-infected control ticks. Our results suggest that BmCYP is a functional enzyme with cysteine protease enzymatic activity and may be involved in tick-B. microti interactions.


Asunto(s)
Proteínas de Artrópodos/metabolismo , Babesia microti/enzimología , Cistatinas/metabolismo , Proteasas de Cisteína/metabolismo , Proteínas Protozoarias/metabolismo , Garrapatas/metabolismo , Garrapatas/parasitología , Secuencia de Aminoácidos , Animales , Proteínas de Artrópodos/genética , Babesia bovis/química , Babesia bovis/enzimología , Babesia bovis/genética , Babesia microti/química , Babesia microti/genética , Babesiosis/parasitología , Cistatinas/genética , Proteasas de Cisteína/química , Proteasas de Cisteína/genética , Humanos , Ratones , Ratones Endogámicos BALB C , Unión Proteica , Proteínas Protozoarias/química , Proteínas Protozoarias/genética , Garrapatas/genética
10.
Infect Genet Evol ; 85: 104466, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32682864

RESUMEN

Frogs are the main source of infection for human sparganosis. In this study, the prevalence and pathogenicity of plerocercoid larvae (sparganum) in frogs collected from the Yangtze River Delta in East China were investigated. A total of 386 frogs belonging to five species were purchased from farmers' markets across all three provincial level areas in the Yangtze River Delta region. The overall prevalence was 4.9% (19/386), and 39 spargana were detected visually, with the intensity ranging from 1 to 11. The spargana infection rate was 7.7% (11/143) in Jiangsu Province and 4.4% (8/181) in Shanghai City, while no spargana infection was detected in Zhejiang Province. In five tested frog species, only Rana nigromaculata and R. limnocharis were found to harbor spargana infection, with a prevalence of 7.7% (13/168) and 6.3% (6/95), respectively. There was no significant difference among the months of the experimental period, July to September. The spargana mostly parasitized the muscle tissues of frogs, especially in the hind legs. All the spargana were identified by molecular analysis based on cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) genes, and all plerocercoids were Spirometra erinaceieuropaei. Nine mice were infected orally with 1 to 3 scoleces, and 77.8% (14/18) of plerocercoids were found in mice at the 30th day post infection. No obvious clinical symptoms were observed in the mice; however, histopathological analysis showed an inflammatory cellular response in all tissues except intestinal tissue. Hematologic analysis showed an increased number of white blood cells (WBCs) at the 18th day post infection. These results indicated that R. nigromaculata and R. limnocharis are a potential source of zoonotic sparganosis in the Yangtze River Delta of China, and farmed frogs may substantially reduce zoonotic risk as compared to eating wild frogs. Our findings will provide data for frog food safety and prevention and control of sparganosis in the region.

11.
Int J Nurs Pract ; 26(5): e12872, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32686257

RESUMEN

AIM: The aim of the study was to examine whether patient-provider communication interacts with treatment outcomes to influence patients' risk perception. BACKGROUND: Medical uncertainties and risks are among the most serious problems faced by patients. This is exacerbated by communication failure in patient-provider relationships and poor treatment outcomes. However, we do not know how communication and treatment outcomes shape patients' risk perception and concern about uncertainty. DESIGN: The study is a two-by-two between-subjects design. METHODS: Two studies were conducted and data were collected in 2019. Each study used a different research design and different samples: Study 1 used a scenario experiment with 120 undergraduate students; and Study 2 surveyed 200 inpatients in clinical settings. RESULTS: The convergent results found a significant interaction between patient-provider communication and treatment outcome on the perception of medical risks among the participants. CONCLUSION: Patient-provider communication interacts with treatment outcome to influence patients' perceived risk about uncertainties for healthcare. Clinicians and nurses should be aware of the effects of patient-provider communication on patients' risk perception in their concerns about the uncertainties of treatment and pay much more attention to good healthcare relationship building in addition to the improvement of objective treatment outcome.

12.
Ticks Tick Borne Dis ; 11(4): 101446, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32340913

RESUMEN

Pathogens and cancer cells employ the programmed cell death-Ligand 1 (PD-L1)/ programmed cell death-1 (PD-1) signaling pathway to inhibit the immune response. Hence, blockade of PD-L1/PD-1 recognition through monoclonal antibodies enhances the immune response. Antibodies that block PD-L1 and PD-1 binding have been used for the prevention and therapy of human pathogenic diseases, but have not yet been evaluated for the treatment of infectious diseases of livestock. In the present study, a recombinant vaccine named PROF-PDL1E, was designed comprising the Babesia microti-derived vaccine candidate profilin and the host PD-L1 protein, and its effect on immunization against murine B. microti infection was evaluated. PD-L1-specific antibodies generated after vaccination blocked PD-L1 and PD-1 binding as shown by in vitro assays. PROF-PDL1E reduced the burden of B. microti in a mouse model and decreased PD-1 expression in T cells. Furthermore, no tissue damage could be observed after PROF-PDL1E vaccination as verified by hematoxylin and eosin tissue staining of essential organs. In conclusion, vaccines targeting immune checkpoints seem to be a promising strategy for anti-Babesia vaccine development.

13.
Virol Sin ; 35(4): 398-406, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32157603

RESUMEN

Ticks are involved in the transmission of various arboviruses and some tick-borne viruses pose significant threats to the health of humans or livestock. This study aimed to investigate the geographical distribution of tick species and tick-associated viruses in central and eastern China. Total 573 ticks from domestic animals including dogs, sheep and cattle were collected in 2017. Two genera of ticks were identified including Rhipicephalus and Haemaphysalis. Sequencing was performed on Miseq Illumina platform to characterize the tick viromes from the four different sampling locations. Following trimming, 13,640 reads were obtained and annotated to 19 virus families. From these sequences, above 37.74% of the viral reads were related to the RNA viruses. Virome comparison study revealed that the tick viral diversity was considerably different in the two identified tick genera. The viral diversity of R. microplus was significantly different from that of other Rhipicephalus species. On the other hand, substantial overlap in viral species was observed between the same genera. In addition, we found no evidence that the natural host played a major role in shaping virus diversity based on the comparison of their viromes. Rather, the geographic location seems to significantly influence the viral families. Phylogenetic study indicated that the novel negative-sense RNA viruses identified in this study was closely related to Bole tick virus 1 and 3 viruses. In conclusion, the present study provides a baseline for comparing viruses detected in ticks, according to species, natural hosts, and geographic locations.

14.
Parasitol Int ; 76: 102094, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32109578

RESUMEN

Toxoplasma gondii is a pathogen that seriously threatens the health of humans and animals. However, the current infection status of T. gondii in slaughter pigs in Shanghai is still not clear. To investigate the seroprevalence of T. gondii infection and analyze the prevalence factors associated with the parasite infection, 1158 serum samples were collected from five slaughterhouses in three districts between 2015 and 2018. Serum antibodies against T. gondii were detected in 160 pigs (13.8%) by enzyme-linked immunosorbent assay (ELISA). Additionally, seroprevalence rates differed among different districts (ranging from 4.0% in JD-2 to 17.6% in JD-1), seasons (ranging from 6.7% in winter to 17.8% in autumn), and years (ranging from 8.0% in 2016 to 26.8% in 2015). Region, season, and year were the main factors affecting T. gondii infection in these pigs. There were few reports on serological monitoring of T. gondii in Shanghai slaughterhouses between 2015 and 2018, and the number of infections had steadily increased over the past several consecutive years. Therefore, our data are helpful to understand the epidemic status of T. gondii in Shanghai, which will strengthen the prevention and treatment of swine toxoplasmosis.


Asunto(s)
Enfermedades de los Porcinos/epidemiología , Toxoplasma/aislamiento & purificación , Toxoplasmosis Animal/epidemiología , Mataderos , Animales , China/epidemiología , Femenino , Masculino , Prevalencia , Estudios Seroepidemiológicos , Porcinos , Enfermedades de los Porcinos/parasitología , Toxoplasmosis Animal/parasitología
15.
Prog Retin Eye Res ; 75: 100777, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31493487

RESUMEN

The mucosal glycocalyx of the ocular surface constitutes the point of interaction between the tear film and the apical epithelial cells. Membrane-associated mucins (MAMs) are the defining molecules of the glycocalyx in all mucosal epithelia. Long recognized for their biophysical properties of hydration, lubrication, anti-adhesion and repulsion, MAMs maintain the wet ocular surface, lubricate the blink, stabilize the tear film and create a physical barrier to the outside world. However, it is increasingly appreciated that MAMs also function as cell surface receptors that transduce information from the outside to the inside of the cell. A number of excellent review articles have provided perspective on the field as it has progressed since 1987, when molecular cloning of the first MAM was reported. The current article provides an update for the ocular surface, placing it into the broad context of findings made in other organ systems, and including new genes, new protein functions and new biological roles. We discuss the epithelial tissue-equivalent with mucosal differentiation, the key model system making these advances possible. In addition, we make the first systematic comparison of MAMs in human and mouse, establishing the basis for using knockout mice for investigations with the complexity of an in vivo system. Lastly, we discuss findings from human genetics/genomics, which are providing clues to new MAM roles previously unimagined. Taken together, this information allows us to generate hypotheses for the next stage of investigation to expand our knowledge of MAM function in intracellular signaling and roles unique to the ocular surface.

16.
Exp Appl Acarol ; 80(1): 71-89, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31828557

RESUMEN

Clathrin plays an important role in arthropods, but its function in ticks has not been explored. Here, we describe the molecular characteristics of the clathrin heavy chain of the tick Rhipicephalus haemaphysaloides and its effects on yolk development. The open reading frame of the clathrin heavy chain (Chc) (Rh-Chc) gene consists of 5103 nucleotides encoding 670 amino acids, which is most closely related to that of Ixodes scapularis and relatively close to Homo sapiens and Drosophila melanogaster. Real-time qPCR revealed that Rh-Chc was expressed at all developmental stages and organs. After Rh-Chc is silenced, ticks did not feed and mortality rate was 100%. Moreover, Rh-Chc co-localized with Vitellogenin receptor (VgR) on oocyte membrane. Immunofluorescence showed that the expression of Vitellogenin (Vg) (Rh-Vg) was also closely related to Rh-Chc. Immunofluorescence showed that the expression of Vg was also closely related to Rh-Chc, Rh-Chc silencing slowed the development of oocytes in tick, and culture of ovary in vitro silenced Rh-Chc, the development of oocytes in ticks also slowed down. Overall, the results of this study indicated that Rh-Chc is a vital gene in the tick R. haemaphysaloides that plays an important role in its growth, development, and reproduction.


Asunto(s)
Cadenas Pesadas de Clatrina/genética , Endocitosis , Rhipicephalus/genética , Vitelogeninas/metabolismo , Animales , Femenino , Oocitos , Ovario
17.
Artículo en Inglés | MEDLINE | ID: mdl-31806762

RESUMEN

The cause of the elevated outflow resistance and consequent ocular hypertension characteristic of glaucoma is unknown. To investigate possible causes for this flow resistance, we used atomic force microscopy (AFM) with 10-µm spherical tips to probe the stiffness of the inner wall of Schlemm's canal as a function of distance from the tissue surface in normal and glaucomatous postmortem human eyes, and 1-µm spherical AFM tips to probe the region immediately below the tissue surface. To localize flow resistance, perfusion and imaging methods were used to characterize the pressure drop in the immediate vicinity of the inner wall using giant vacuoles that form in Schlemm's canal cells as micropressure sensors. Tissue stiffness increased with increasing AFM indentation depth. Tissues from glaucomatous eyes were stiffer compared with normal eyes, with greatly increased stiffness residing within ∼1 µm of the inner-wall surface. Giant vacuole size and density were similar in normal and glaucomatous eyes despite lower flow rate through the latter due to their higher flow resistance. This implied that the elevated flow resistance found in the glaucomatous eyes was localized to the same region as the increased tissue stiffness. Our findings implicate pathological changes to biophysical characteristics of Schlemm's canal endothelia and/or their immediate underlying extracellular matrix as cause for ocular hypertension in glaucoma.

18.
Parasit Vectors ; 12(1): 341, 2019 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-31296257

RESUMEN

BACKGROUND: Rhipicephalus haemaphysaloides is a widespread tick species in China and other South East Asian countries, where it is the vector of many pathogens. The objective of this study was to study the role of serpin (serine protease inhibitor) during the tick-host interaction. METHODS: The differentiation of bone marrow-derived dendritic cells (BMDC) was induced in vitro, and the effect of RHS2 on the maturation of DCs was evaluated. The effects of RHS2 on T cell activation and cytotoxic T lymphocytes' (CTLs) activity were analyzed by flow cytometry. Antibody subtypes after immunization of mice with RHS2 and OVA were determined. RESULTS: RHS2 can inhibit the differentiation of bone marrow-derived cells into DCs and promote their differentiation into macrophages. RHS2 can inhibit the maturation of DCs and the expression of CD80, CD86 and MHCII. The number of CD3+CD4+ and CD3+CD8+ T cells secreting IFN-γ, IL-2 and TNF-α was decreased, and the number of CD3+CD4+ T cells secreting IL-4 was increased, indicating that RHS2 can inhibit the activation of CD4 T cells and CD8 T cells, leading to inhibition of Th1 immune response. RHS2 inhibits the elimination of target cells by cytotoxic T lymphocytes. After immunization of mice with RHS2 and OVA, serum IgG2b was significantly reduced and IgM was increased. CONCLUSIONS: The results show that RHS2 has an inhibitory effect on the host immune response. Ticks have evolved various ways to circumvent adaptive immunity. Their serpin inhibits BMDC differentiation to reduce immune responses.


Asunto(s)
Células Dendríticas/inmunología , Interacciones Huésped-Parásitos , Inmunomodulación , Activación de Linfocitos , Rhipicephalus/química , Serpinas/inmunología , Animales , Células de la Médula Ósea/inmunología , Linfocitos T CD8-positivos/inmunología , Diferenciación Celular/efectos de los fármacos , Femenino , Citometría de Flujo , Ratones Endogámicos BALB C , Serpinas/genética
19.
Ticks Tick Borne Dis ; 10(5): 1018-1027, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31151924

RESUMEN

Babesia microti is an emerging zoonotic pathogen that is transmitted by ticks and parasites and propagates in mammalian erythrocytes. Thioredoxin reductase (TrxR) plays a crucial role in B. microti survival by maintaining cellular redox homeostasis. In the present study, 4-nitro-2,1,3-benzothiadiazole (4-NBT) was selected as a specific B. microti TrxR inhibitor by comparing rat and parasite TrxR inhibition levels. Reactive oxygen species (ROS) levels were evaluated using flow cytometry, and in B. microti treated with 4-NBT, ROS levels increased with increasing inhibitor concentration. Furthermore, the inhibitor treatment increased lipid peroxidation and protein carbonyl levels, thus indicating a state of oxidative stress. While B. microti treated with 4-NBT appeared to lose the ability to multiply in mice, the fastigium of parasitemia between the treated and control groups was comparable. Furthermore, a TUNEL assay showed that 4-NBT induces apoptosis in B. microti. Proteomic analysis of B. microti treated with 4-NBT detected 960 proteins. Label-free quantitative proteomic analysis identified 118 proteins that were significantly up-regulated and 37 that were significantly down-regulated in the treatment group relative to the control. Of the differential proteins, proteasome and ribosomal subunit expression was up-regulated, thus suggesting that redundant proteins may be damaged by oxidation and waiting for degradation, while proteins for subsistence are waiting for de novo synthesis. Moreover, the findings obtained herein suggest that the DNA and lipids were also damaged and awaiting synthesis or repair. In conclusion, TrxR dysfunction in B. microti results in the breakdown of redox homeostasis and promotes apoptosis.


Asunto(s)
Babesia microti/efectos de los fármacos , Proteoma/efectos de los fármacos , Proteínas Protozoarias/antagonistas & inhibidores , Tiadiazoles/farmacología , Reductasa de Tiorredoxina-Disulfuro/antagonistas & inhibidores , Animales , Babesia microti/química , Babesia microti/metabolismo , Eritrocitos/parasitología , Proteoma/metabolismo , Ratas
20.
Invest Ophthalmol Vis Sci ; 60(5): 1630-1643, 2019 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-30995299

RESUMEN

Purpose: We investigated whether cellular connectivity between Schlemm's canal (SC) inner wall (IW) endothelium, and juxtacanalicular connective tissue (JCT), and between IW endothelial cells, plays a role in giant vacuole (GV) and pore formation by comparing perfusion- and immersion-fixed eyes. Methods: Normal human donor eyes (n = 4) were either immersion-fixed (0 mm Hg) or perfusion-fixed (15 mm Hg). Trabecular meshwork near SC was imaged using serial block-face scanning electron microscopy. A total of 12 IW cells from each group were 3D-reconstructed from ∼7040 electron micrographs and compared. In each cell, connections between IW cells and JCT cells/matrix were quantified; IW/IW connectivity was measured by cell border overlap length. GV volume, density, shape, and intracellular and paracellular pores were analyzed. Results: The mean number of IW/JCT cell-cell connections per cell significantly decreased (P < 0.01) while the summed GV volume per cell significantly increased (P < 0.01) in perfusion-fixed eyes compared to immersion-fixed eyes. Intracellular pores were observed in 14.6% of GVs in perfusion-fixed eyes and not observed in immersion-fixed eyes. The mean IW/IW overlap length per cell decreased (P < 0.01), and paracellular pores were found only in regions where IW/IW connectivity was minimal (overlap length = 0 µm) in perfusion-fixed eyes and not observed in immersion-fixed eyes. Conclusions: Our data suggest that changes in IW/JCT connectivity may be an important factor in the formation of larger GVs, and decreased IW/IW connectivity may promote paracellular pore formation. Targeting the IW/JCT and IW/IW connectivity may therefore be a potential strategy to regulate outflow resistance and IOP. .


Asunto(s)
Comunicación Celular/fisiología , Endotelio/ultraestructura , Uniones Intercelulares/ultraestructura , Limbo de la Córnea/ultraestructura , Malla Trabecular/ultraestructura , Vacuolas/fisiología , Adulto , Anciano , Tejido Conectivo/ultraestructura , Humanos , Procesamiento de Imagen Asistido por Computador , Imagenología Tridimensional , Microscopía Electrónica de Rastreo , Donantes de Tejidos , Fijación del Tejido/métodos
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