[PD-1/PD-L1 expression and its interaction with interferon-γ in Toxoplasma gondii-infected mice at middle and late pregnancy]

OBJECTIVE

To explore the dynamic expression of programmed cell death-1 (PD-1) and its ligand PD-L1 at the maternal-fetal interface of mice post-infection with Toxoplasma gondii at early pregnancy and examine its interaction with interferon-γ (IFN-γ).

METHODS

A total of 20 mice at day 0 of pregnancy were randomly assigned into 4 groups, including the 12-day pregnancy control group (12 dpn group), 12-day pregnancy and infection group (12 dpi group), 18-day pregnancy control group (18 dpn group) and 18-day pregnancy and infection group (18 dpi group), respectively. On the 6th day of the pregnancy, mice in the 12 dpi and 18 dpi groups were injected intraperitoneally with 150 tachyzoites of the T. gondii PRU strain, while mice in the 12 dpn and 18 dpn groups were injected with the same volume of PBS. All mice in the four groups were sacrificed on 12th and 18^th day of the pregnancy, and the number of placenta and fetus was counted and the weight of placenta and fetus was measured. Then, the placental and uterine tissues of the pregnant mice in each group were sampled for pathological examinations. The mRNA expression of PD-1, PD-L1, T. gondii surface antigen SAG-1 and IFN-γ genes was quantified using a quantitative real-time PCR (qPCR) assay, and the correlation between PD-1 and IFN-γ expression was examined. In addition, the 12 dpn group, 12 dpi group, 18 dpn group, 18 dpi group, PBS negative control of the 12 pdi group and PBS negative control of the 18 dpi group were assigned, and the PD-1 expression was determined in the uterine and placenta tissues of the pregnant mice.

RESULTS

Adverse pregnant outcomes were seen in mice in the 12 dpi and 18 dpi groups, including placental dysplasia and fetal maldevelopment, and the placental weights and fetal body weights were significantly lower in mice in the 12 dpi and 18 dpi groups than those in the 12 dpn and 18 dpn groups (t = 5.52, 11.44, 12.63 and 11.67, all P < 0.01). The histopathological examinations showed that the decidua and junctional regions of the placental tissues were loosely connected in the 12 dpi and 18 dpi groups, and a large number of inflammatory cells infiltration and congestion were seen in the placental and uterine tissues. qPCR assay detected significant differences in PD-1, PD-L1, IFN-γ and SAG-1 expression in the placental and uterine tissues among the 12 dpn, 12 dpi, 18 dpn and 18 dpi groups (F = 22.48, 51.23, 9.61, 47.49, 16.08, 21.52, 28.66 and 238.90, all P < 0.05), and the PD-1, PD - L1, IFN - γ and SAG - 1 expression was all significantly higher in the placental and uterine tissues of mice in the 12 dpi group than in the 12 dpn group (all P values < 0.05). The PD-1 and PD-L1 expression was significantly lower in the placental tissues of mice in the 18 dpi group than in the 18 dpn group (all P values < 0.05), and the IFN-γ and SAG-1 expression was significantly higher in the placental and uterine tissues of mice in the 18 dpi group than in the 18 dpn group (all P values < 0.05), while the PD-1 and PD-L1 expression was significantly lower in the placental and uterine tissues of mice in the 18 dpi group than in the 12 dpi group (all P values < 0.05). Immunohistochemical staining showed PD-1 expression in the inflammatory cells of the placental tissues of mice in the 12 dpi group, and no apparent PD-1 expression in the 18 dpi group, while strongly positive PD-1 expression was found in the uterine epithelium of mice in the 12 dpi group, and mildly strong expression was in the 18 dpi group. In addition, the IFN-γ mRNA expression was positively correlated with the PD-1 mRNA expression in placental (r_s = 0.99, P < 0.01) and uterine tissues of mice in the 12 dpi group (r_s = 0.97, P < 0.01) and in placental (r_s = 0.82, P < 0.01) and uterine tissues of mice in the 18 dpi group (r_s = 0.81, P < 0.01).

CONCLUSIONS

Following T. gondii infection at early pregnancy, the PD-1 and PD-L1 expression shows a remarkable rise at middle pregnancy and a reduction at late pregnancy in placental and uterine tissues of mice, which appears the same tendency with IFN-γ expression during the same time period, and PD-1 expression positively correlates with IFN-γ expression. The dynamic expression of PD-1 and PD-L1 on the maternal-fetal interface of mice may be mutually mediated by IFN-γ induced by T. gondii infection.

[Expression of hypoxia-inducible factor-1 in mice infected with Toxoplasma gondii during pregnancy]

OBJECTIVE

To investigate the expression and possible role of hypoxia-inducible factor-1 (HIF-1) at the maternal-fetal interface following Toxoplasma gondii infection during early pregnancy.

METHODS

Twenty pregnant C57BL/6 mice, each weighing 16 to 20 g, were randomly divided into 4 groups, including the 12-d control group, 12-d infection group, 18-d control group and 18-d infection group. Mice in the 12-d and 18-d infection groups were injected intraperitoneally with 150 tachyzoites of the T. gondii PRU strain on day 6 of pregnancy, while mice in the 12-d control and 18-d control groups were injected with the same volume of phosphate buffered saline (PBS). Mice in the control and infection groups were sacrificed on days 12 and 18 of pregnancy, and the placental and uterine specimens of the pregnant mice in each group were sampled for pathological examinations. The mRNA expression of HIF-1α, HIF-1β and vascular endothelial growth factor (VEGF) was quantified using quantitative fluorescent real-time PCR (qPCR) assay in the placental and uterine specimens, and the correlation between HIF-1α and VEGF mRNA expression was examined. In addition, and the HIF-1α expression was detected using immunohistochemical staining in the placental and uterine specimens of pregnant mice.

RESULTS

Compared with the 12-d and 18-d control groups, adverse pregnant outcomes were observed in mice in 12-d and 18-d infection groups, such as teratism and placental dysplasia. HE staining showed swelling and blood stasis of cells, sinusoid reduction and inflammatory cell infiltration in the labyrinth area of the placenta specimens of mice in 12-d and 18-d infection groups relative to 12-d and 18-d control groups, and columnar epithelial cell injury and inflammatory cell infiltration were seen in the mouse uterine specimens in both infection groups. qPCR assay detected significantly higher HIF-1α (F = 132.6, P < 0.05) and HIF-1β mRNA expression (F = 286.9, P < 0.05) in the placental specimens and lower HIF-1α (F = 111.5, P < 0.05) and HIF-1β mRNA expression (F = 55.2, P < 0.05) in the uterine specimens in the 12-d infection group than in the 12-day control group, and significantly lower HIF-1α and HIF-1β mRNA expression was detected in the placental and uterine specimens in the 18-d infection group than in the 18-day control group (F = 215.8, 418.9, 156.8 and 200.1; all P values < 0.05). Significantly lower VEGF-A (F = 426.2, P < 0.05), VEGF-B (F = 104.6, P < 0.05) and VEGF-C mRNA expression (F = 566.9, P < 0.05) in the placental specimens and higher VEGF-A (F = 426.2, P < 0.05), VEGF-B (F = 104.6, P < 0.05) and VEGF-C mRNA expression (F = 566.9, P < 0.05) in the uterine specimens were detected in the 12-d infection group than in the 12-d control group, and higher VEGF-A, VEGF-B and VEGF-C mRNA expression was found in the placental and uterine specimens in the 18-d infection group than in the 18-d control group (F = 521.9, 100.6, 275.9, 224.6, 108.2 and 333.4; all P values < 0.05). Immunohistochemical staining showed strongly and mildly positive HIF-1α expression in the mouse placental labyrinth area in the 12-d and 18-d infection groups relative to 12-d and 18-d control groups, while no HIF-1α expression was detected in mouse uterine specimens.

CONCLUSIONS

HIF-1α expression appears a tendency towards a rise in the second trimester and a reduction in the third trimester in mice following T. gondii infection during early pregnancy, which is contrary to the changing tendency of VEGF-A, VEGF-B, and VEGF-C expression. It is hypothesized that HIF-1α inhibits placental angiogenesis in mice during pregnancy through suppressing VEGF expression, resulting in adverse pregnant outcomes.

[Study on the mechanisms of the intestinal tight-junction destruction caused by Blastocystis hominis infection in rats]

OBJECTIVE

To explore the mechanism of the intestinal barrier damage caused by Blastocystis hominis infections in rats.

METHODS

Thirty SD rats were randomly divided into the control group, and the 1-, 3-, 6- and 9-week-infection groups, of 6 rats in each group. Rats in each infection group were orally infected with B. hominis trophozoites at a density of 2 × 10⁸ parasites per rat, and the control group was given an equal volume of phosphate buffered saline solution. The 7-hour urine samples were collected 1, 3, 6 and 9 weeks post-infection for the measurement of the intestinal permeability. Then, rats were sacrificed using the cervical dislocation method, and the cecum specimens were collected for the detection of the intestinal epithelial cell permeability. The expression of tight junction-related Occludin and Claudin - 1 genes and apoptosis-related Bcl - 2 and Bax genes was quantified in cecum epithelial cells using the real-time fluorescent quantitative PCR (qPCR) assay, and cell apoptosis was detected in the rat cecum using the TdT-mediated dUTP nick-end labeling (TUNEL) assay.

RESULTS

The median urinary lactolose to mannitol ratios were 0.29, 0.72, 0.44, 0.46 and 0.38 in the control group, and the 1-, 3-, 6- and 9-week-infection groups, respectively, and the difference was statistically significant (H = 12.09, P < 0.05). B. hominis invasion and epithelial injury were observed in intestinal epithelial cells of rats infected with B. hominis, and transmission electron microscopy displayed the destruction of tight junctions between intestinal epithelial cells. The relative expression of Occludin, Claudin-1, Bcl-2 and Bax genes was 1.04, 0.62, 0.71, 0.68 and 0.96; 1.03, 0.61, 0.63, 0.76 and 0.86; 1.08, 0.70, 0.75, 0.74 and 1.03; and 1.00, 1.57, 1.33, 1.35 and 1.10 in the control group and the 1-, 3-, 6- and 9-week-infection groups, respectively, and all differences were statistically significant (F = 2.86, 2.85, 3.37 and 4.45, all P values < 0.05). The median number of positive staining cells were 1.00, 13.00, 9.00, 3.50 and 1.00 in rat cecum specimens in the control group, and the 1-, 3-, 6- and 9-week-infection groups, respectively, and the difference was statistically significant (H = 22.95, P < 0.01).

CONCLUSIONS

B. hominis infection may cause an increase in the rat intestinal permeability through triggering the apoptosis of intestinal epithelial cells to destroy the tight junction between intestinal epithelial cells, thereby destroying the intestinal barrier function.

FRI0573 VALIDATION OF FOUR SCREENING TOOLS FOR PSORIATIC ARTHRITIS IN CHINESE PATIENTS WITH PSORIASIS: A MULTICENTER STUDY

Background:

Psoriatic arthritis (PsA) is a chronic inflammatory arthropathy affecting 6~30% of patients with skin or nail psoriasis. If PsA is not identified early and managed appropriately, progressive joint damage with deformities and disability may occur. Preliminary efforts to develop screening tools for the identification of PsA have met with variable success. Whether the tools function well or not in Chinese patients remains unknown.

Objectives:

We aimed to validate and compare the performance of 4 PsA screening tools in Chinese psoriasis patients.

Methods:

Consecutive psoriasis patients (dermatology cohort) attending dermatology clinics without previous diagnosis of inflammatory arthritis and consecutive newly diagnosed PsA patients (rheumatology cohort) attending rheumatology clinics were invited to complete the questionnaires: early arthritis for psoriatic patients (EARP), psoriatic arthritis screening and evaluation(PASE), psoriasis and arthritis screening questionnaire(PASQ), and psoriasis epidemiology screening tool (PEST). Receiver operating characteristic (ROC) curves were utilized to calculate diagnostic accuracy, least absolute shrinkage and selection operator(lasso) and binary logistic regressions to identify the most discriminative questions.

Results:

In this multicenter study, 379 patients in the dermatology cohort and 72 in the rheumatology cohort were recruited. In the dermatology cohort, 7.9% (30/379) were newly diagnosed with PsA. The EARP and PASQ tools demonstrated better discriminating ability for identifying PsA from psoriasis patients (yielded sensitivities/specificities were: 93.3%/92.3% and 90.0%/90.5%, while optimal cut-off values were: 3 and 5, respectively), and the good performance of EARP and PASQ was further confirmed in the rheumatology cohort. However, all these tools demonstrated low sensitivities (about 30%) with regard to screening the axial PsA. Based on the questions, a risk prediction model of PsA was established.

Conclusion:

The prevalence rate of undiagnosed PsA in the patients with psoriasis is 7.9%. Both EARP and PASQ tools show better favorable trade-off between sensitivity and specificity than PASE and PEST, while all the 4 tools are not sensitive to identify axial PsA.

References:

[1] Villani AP, Rouzaud M, Sevrain M, et al. Prevalence of undiagnosed psoriatic arthritis among psoriasis patients: Systematic review and meta-analysis.Journal of the American Academy of Dermatology2015;73(2): 242-8.

[2] Tinazzi I, Adami S, Zanolin EM, et al. The early psoriatic arthritis screening questionnaire: a simple and fast method for the identification of arthritis in patients with psoriasis.Rheumatology (Oxford, England) 2012;51(11): 2058-63.

[3] Majed Khraishi IL, Gerry Mugford. The Self-Administered Psoriasis and Arthritis Screening Questionnaire (PASQ): A Sensitive and Specific Tool for the Diagnosis of Early and Established Psoriatic Arthritis.Psoriasis Forum2010;16(2): 9-16.

[4] Husni ME, Meyer KH, Cohen DS, Mody E, Qureshi AA. The PASE questionnaire: pilot-testing a psoriatic arthritis screening and evaluation tool.Journal of the American Academy of Dermatology2007;57(4): 581-7.

[5] Ibrahim GH, Buch MH, Lawson C, Waxman R, Helliwell PS. Evaluation of an existing screening tool for psoriatic arthritis in people with psoriasis and the development of a new instrument: the Psoriasis Epidemiology Screening Tool (PEST) questionnaire.Clinical and experimental rheumatology2009;27(3): 469-74.

Acknowledgments:

This project was supported by grants from National Natural Science Foundation of China (81771746 and 81471604).

Disclosure of Interests:

None declared

[The 472nd case: dyspnea, pulmonary shadows, abnormalities of whole blood cells]

A 54-year-old man was admitted to respiratory department with chief complaints of recurrent cough and dyspnea. Chest imaging showed multiple patchy shadows and interstitial changes. Evidence of infectious diseases was not definite, and antibiotic treatments were not effective. In the meantime, myelodysplasia syndrome was diagnosed with pancytopenia. The pathologic findings of transbronchoscopic lung biopsyshowed chronic inflammatory interstitial changes, suggesting a clinical diagnosis of organizing pneumonia. After glucocorticoids treatment, his condition aggravated. The second percutaneous lung biopsy showed the infiltration of a large number of neutrophils. Therefore, the final diagnosis of myelodysplasia syndrome with Sweet syndrome was made. Then glucocorticoids and supportive treatment were given This case may improve physicians' understanding of myelodysplasia syndrome complicated with Sweet syndrome.

Arotinoid trometamol inhibits arsenic trioxide-stimulated keratinocyte proliferation via the Wnt, Shh, and bone morphogenetic protein signaling pathways

Arsenic acts as a human carcinogen and contributes to skin cancer via mechanisms that remain largely unknown. Recent evidence implicates the perturbation of Wnt, Shh and BMP signals as a potential mechanism. We initiated studies to examine gene expression changes in these signaling pathways. Meanwhile, the antagonistic effect of retinoic acid was explored. In this study, HaCaT and NHEK cells were treated with arsenic trioxide (As2O3) alone or in combination with arotinoid trometamol (retinoic acid receptor agonist). Flow cytometric analysis, PCR array and Western blot were used to determine the potential mechanism and signaling pathways associated with arsenic carcinogenesis. The results showed that low concentration As2O3 could stimulate keratinocyte proliferation, and arotinoid trometamol inhibited the process via regulating the expression of about 20 genes. These genes included components of Wnt signaling (CSNK1A1L, CTNNB1, SFRP1, Wnt10B, Wnt11, Wnt16, Wnt5A, Wnt8A), Shh signaling (C6orf138, HHIP, PTCHD1) and BMP signaling pathway (BMP2, BMP7). The changes of some differentially expressed genes of these signaling pathways in As2O3 treatment group were counteracted by the subsequent arotinoid trometamol treatment. Our data suggest that dysregulation and cross-talk of Wnt, Shh and BMP signals play great roles in the process of arsenic-induced carcinogenesis, which could be antagonized by arotinoid trometamol.

[Spatial-temporal analysis of pulmonary tuberculosis in Shandong province, 2015]

Objective: To analyze the spatial-temporal epidemiological characteristics of active pulmonary tuberculosis (PTB) and sputum smear positive (SS+) PTB in Shandong province, China, 2015. Methods: The surveillance data of active PTB and SS+PTB in Shandong in 2015 were collected and analyzed by using the global and local indicators of spatial association (Moran's I) for the spatial autocorrelation of PTB, and by using SaTScan forspatial-temporal clustering characteristics of PTB based on geographic information system. Results: Totally, 31 776 active PTB cases and 8 631 SS+PTB cases were reported in Shandong in 2015, and the reported incidence rates of active PTB and SS+PTB were 33.09/100 000 and 8.99/100 000, respectively. Active PTB had positive spatial autocorrelation at county level, and the value of Moran's I value was 0.219 (P<0.001), indicating that the high-high (HH) aggregation areas with high incidence were in the northwestern, southeastern and central southern Shandong; SS+PTB also had positive spatial autocorrelation at county level, and the value of the Moran's I was 1.178 (P<0.001), indicating that the HH aggregation areas with high incidence were in the southeastern and northwestern Shandong. The results of spatial-temporal scanning indicated that there was incidence clustering of active PTB in the second quarter and the third quarter in 2015, and the clustering areas were in the central southern, southeastern and northwestern Shandong; there also was incidence clustering of SS+PTB in the second quarter and the third quarter in 2015, and the clustering areas were in the southeastern and northwestern Shandong. Conclusions: The incidence of active PTB and SS+PTB showed spatial and temporal clustering in Shandong in 2015. The areas with high PTB burden and high PTB transmission risks were in the northwestern and southeastern Shandong. The areas with high PTB burden but without high PTB transmission risks were in the central southern Shandong.

[Structural and functional study of prokaryotic enhancer-like element VV1 from vaccinia virus]

Enhancer VV1 (about 283 bp) is selected as the target to analyze its structure and function systemically. Stepwise deletion experiment is used to identify the functional domain of VV1 element. The results suggest that the 20 bp at 5' terminal and 20 bp at 3' terminal are important to the activity of VV1, for without either of them its activity decreased greatly. Furthermore, the 30-50 bp at 5' terminal is essential to its activity, without which will lead to complete loss of its activity. By random mutagenesis assay it is found that base mutation can regulate the activity of enhancer VV1 positively or negatively. The more the activities of mutants descend, the more mutations take place. For singlebase mutation, the activities change relatively little, and most of the mutations always occur in the 50 bp at the 5' terminal.

[Functional and structural study of the prokaryotic enhancer-like element VV16 from vaccinia virus genome]

An enhancer-like element VV16 from Vaccinia virus genome DNA was obtained by using the plasmid with CAT reporter gene. Sequence analysis showed the element of 112 bp is a part of the DNA-dependent RNA polymerase, polyA polymerase and DNA polymerase (RPO30 gene). It contains 4 AT-rich regions. Detection of beta-galactosidase activity showed that VV16 in the positive direction can increase the activity 9.0 times and VV16 in the negative direction can increase 4.1 times. The RNA dot blotting confirmed the enhancing activity of the element are on the transcription level. DNA deletion experiment indicated the sequences of 10 bp at the 5' end and 12 bp at the 3' end in the element are important to its function and the sequence from nt76 to nt82 is essential to its activity.

[Functional and structural analysis of a prokaryotic enhancer-like element in Escherichia coli MC1061 strain]

Cat and lacZ genes were used as reporter gene and three prokaryotic enhancer-like element (MC2, MC8 and MC9) were identified in the genomic DNA of MC1061 strain. All three fragments can improve the expression of lacZ gene by 2-5 times with the orientation independence. The results of in vivo transcription and Dot blot hybridization assays suggested that MC8 regulated the expression of lacZ at transcription level. Stepwise deletion expreriments showed the functional domain of MC8 located at 450-950 bp, and in regions 450-600 bp and 840-950 bp contain at least one functional loci. Sequence data indicated three are 3 A + T rich sections in MC8, 2 of them are in the functional loci.

[Secretory carcinoma of the breast as a separate entity--histological, histochemical and ultrastructural study]

A rare case of secretory carcinoma of the breast in a 50 year old woman is presented. The tumor, 1.4 cm in diameter, was located in subareola of the left breast. Microscopically, the majority of the tumor cells were arranged in sheets or large clusters, which were separated by fibrous septa, and a few of the tumor cells in ductal pattern. Most of the tumor cells contained a single large cyst-like space, some of which even occupied the entire cytoplasm. In these tumor cell clusters, gland-like spaces lined by cuboidal cells were also present. Within intracellular and intercellular spaces there was abundant secretory material, which consisted mostly of sulfomucins and less sialomucins as proved by histochemical stain. Electron microscopic examination showed numerous intracellular and extracellular lumina filled with moderate electron-dense granular material as well as high electron-dense spherical bodies. There were microvilli projecting on the surface. Some tumor cells contained large number of membrane-bound secretory vacuoles with small spherical bodies. The tumor cells were attached to each other by desmosomes and junction complexes.