ß-glucan from Saccharomyces cerevisiae is involved in immunostimulation of ovine ruminal explants.

In this study, we investigated whether ß-glucan from Saccharomyces cerevisiae exerts beneficial effects on mucosal immunity in an ovine ruminal explant (ORE) model. Once the ORE model was established, viability was assessed through histological change, E-cadherin expression, CK-18 and Ki-67 distribution. Then, the OREs were co-cultured with ß-glucan, following which, gene and protein expression levels of sheep ß-defensin-1 (SBD-1), pro-inflammatory interleukin (IL)-6, and anti-inflammatory IL-10 were detected using quantitative real-time polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay (ELISA). Hematoxylin & eosin staining, qPCR, and immunohistochemistry showed that the overall ORE structure was intact after 96 hours in culture, but explants cultured for more than 24 hours showed epithelial degradation. Therefore, we performed the follow-up test within 24 hours. qPCR and ELISA revealed that the gene and protein expression levels of SBD-1, IL-6, and IL-10 in the OREs significantly increased (P < 0.05) after treatment with ß-glucan compared with controls. This study identified the feasibility and optimal conditions of ORE culture and demonstrated that ß-glucan activates SBD-1, IL-6, and IL-10 secretion in OREs to promote mucosal immunity.

Dans la présente étude nous avons examiné si le ß-glucane de Saccharomyces cerevisiae amène des effets bénéfiques sur l'immunité mucosale dans un modèle d'explant ruminal ovin (ORE). Une fois que le modèle ORE fut établi, la viabilité fut évaluée via les changements histologiques, l'expression d'E-cadhérine et la distribution de CK-18 et Ki-67. Puis, les OREs furent co-cultivés avec du ß-glucane, après quoi, les degrés d'expression des gènes et des protéines ß-défensine-1 ovine (SBD-1), interleukine (IL)-6 pro-inflammatoire et IL-10 anti-inflammatoire furent détectés en utilisant une réaction d'amplification en chaîne par la polymérase quantitative en temps réel (qPCR) et une épreuve immuno-enzymatique (ELISA). Une coloration à l'hématoxyline et éosine, le qPCR et l'immunohistochimie ont montré que la structure globale d'ORE était intacte après 96 heures en culture, mais des explants cultivés pour plus de 24 heures présentaient une dégradation épithéliale. Par conséquent, nous avons effectué les tests de suivi en dedans de 24 heures. Les analyses par qPCR et ELISA ont révélé que les degrés d'expression des gènes et des protéines SBD-1, IL-6 et IL-10 dans les OREs augmentèrent de manière significative (P < 0,05) après un traitement avec du ß-glucane comparativement aux témoins. Cette étude a identifié la faisabilité et les conditions optimales pour la culture d'ORE et a démontré que le ß-glucane active la sécrétion de SBD-1, IL-6 et IL-10 dans les OREs afin de promouvoir l'immunité mucosale.(Traduit par Docteur Serge Messier).

Modulation of SBD-1 expression by Saccharomyces cerevisiae cell wall components in ovine ruminal epithelial cells.

The ovine rumen is an immune interface with the external environment, participating in host defence responses. Ovine ruminal epithelial cells (ORECs) not only have a physical barrier function, but also secrete sheep ß-defensin-1 (SBD-1), which plays a key role in innate and adaptive immunity. Prebiotics are potential alternatives to infeed antibiotics. Saccharomyces cerevisiae cell wall (S.c.CW) is rich in prebiotics, which play roles in improving the growth performance of animals and regulating immunity. Here, we investigated whether S.c.CW induces SBD-1 expression in ORECs, as well as the underlying mechanism. The regulatory mechanisms of S.c.CW-induced up-regulation of SBD-1 were determined using quantitative real-time PCR, enzyme-linked immunosorbent assay, and western blotting. S.c.CW significantly increased the expression of Toll-like receptor 2 (TLR2) and nuclear factor-kappa B (NF-κB), but had no effect on TLR4 expression. TLR2, MyD88, and NF-κB inhibition attenuated the induction of SBD-1 expression by S.c.CW. However, TLR4 inhibition only resulted in attenuated SBD-1 mRNA, having no effect on SBD-1 protein expression. Thus, we conclude that S.c.CW can induce SBD-1 expression and that this induction is regulated by the TLR2-MyD88-NF-κB pathway.

Saccharomyces cerevisiae mannan induces sheep beta-defensin-1 expression via Dectin-2-Syk-p38 pathways in ovine ruminal epithelial cells.

The rumen epithelium of sheep serves as an immune interface with the environment and secretes antimicrobial peptides with bactericidal function against various pathogens. Sheep beta-defensin-1 (SBD-1), an antimicrobial peptide, is secreted from ovine ruminal epithelial cells (OREC) in response to microbial infections. Mannan, the main component of the Saccharomyces cerevisiae cell wall can stimulate innate and regulatory immune responses that could improve the gastrointestinal environment. We aimed at investigating the effects of mannan on SBD-1 expression and the downstream signaling pathways stimulated in OREC. We cultured OREC; assessed the effects of mannan on SBD-1 expression by qPCR and ELISA; and then investigated the underlying signaling pathways using qPCR, ELISA, Western blotting, immunohistochemistry, and immunohistofluorescence. Interestingly, mannan markedly upregulated SBD-1 expression in a concentration- and time-dependent manner. Dectin-2 Mouse mAb, Syk specific inhibitor R406, and specific inhibitors of the p38, ERK1/2, JNK, and NF-κB pathways attenuated mannan-induced SBD-1 expression to varying degrees. These results demonstrate that SBD-1 is upregulated by mannan via the Dectin-2-Syk axis, and this is regulated to a large extent through the mitogen-activated protein kinase (MAPK) p38 and less so through the ERK1/2 and JNK or the NF-κB pathway. Our findings highlight the immunomodulatory effects of mannan on OREC in terms of mannan-induced SBD-1 expression.

Pediatric Infective Endocarditis and Stroke: A 13-Year Single-Center Review.

OBJECTIVE: We explored the relationship between pediatric infective endocarditis and stroke. PATIENTS AND METHODS: All children encountered with infective endocarditis from January 2002 to December 2015 were included as our sample, and their medical records were comprehensively reviewed. RESULTS: Sixty children with infective endocarditis were identified, including 30 boys and 30 girls aged eight months to 18 years (mean ± SD: 10.3 ± 5.6), and om 43 (71.6%) of these individuals had congenital heart disease. Left-sided endocarditis occurred in 25 patients (41.7%), and vegetations were found in 58 individuals (96.6%). The most often encountered microorganisms were Streptococcus viridans and Staphylococcus aureus, which were identified in five and four patients, respectively. Postendocarditis stroke occurred in nine patients, including five with cerebral infarction, two with intracerebral hemorrhage, and one with subarachnoid hemorrhage. The remaining child experienced cerebral infarction, intracerebral hemorrhage and subarachnoid hemorrhage simultaneously. The incidence of stroke in children with left-sided endocarditis was significantly higher than that of which in those who had right-sided endocarditis (32% versus 2.8%, P < 0.01). The most common manifestation of stroke was hemiparesis (55.5%). Two girls died of stroke, and the mortality rate in the patients who had stroke was significantly higher than that in those without stroke (22.2 % versus 3.9 %, P < 0.05). CONCLUSIONS: Our data indicate that stroke is common among children with infective endocarditis, especially in those with left-sided endocarditis, and major stroke may increase their risk of death. Congenital heart disease is the main underlying disease in children with infective endocarditis in China.

Stroke in Patients with Infective Endocarditis: A 15-Year Single-Center Cohort Study.

OBJECTIVE: To explore the relationship between infective endocarditis (IE) and stroke. METHODS: The clinical data of patients diagnosed with IE from January 2003 to December 2017 in Beijing Anzhen Hospital Affiliated to Capital Medical University were retrospectively analyzed. RESULTS: A total of 861 patients (mean age: 40.79 ± 16.27 [SD]) with IE was recruited. Vegetations were confirmed in 97.32% of all the patients, among whom 296 were diagnosed with congenital heart disease and another 53 with rheumatic valvular disease. The most common pathogens were Streptococcus, Staphylococcus, and various types of fungi (13.12, 7.31, and 1.16% respectively). Out of the 138 patients diagnosed with stroke, 101 cases were of ischemic stroke, 23 cases were of hemorrhagic stroke, and 12 cases were of concurrent ischemic and hemorrhagic stroke. There were 31 patients who had infarction lesions in more than 2 vascular systems. The mean age of stroke patients was significantly higher than that of patients without stroke (45.76 ± 17.88 vs. 39.83 ± 15.77, p = 0.000). The incidence of mitral valve vegetation (57.24 vs. 43.01%, p = 0.002), atrial fibrillation (4.34 vs. 1.38%, p = 0.018), fungal infection (2.89 vs. 0.83%, p = 0.038) in patients with stroke was significantly higher than those without stroke. Mitral valve vegetation (OR 1.648; 95% CI 1.113-2.442) and age (OR 1.019; 95% CI 1.007-1.032) were independent risk factors for stroke in IE patients. Stroke increased the risk of hospital deaths (OR 7.673 95%CI 3.634-16.202). CONCLUSION: Stroke is a common complication of IE. Mitral valve vegetation and old age may incerease the risk of stroke in patients with IE.

[The clinical analysis of neurological symptoms in patients with aortic dissection].

OBJECTIVE: To summarize the characteristics of neurological symptoms in patients with aortic dissection. METHODS: The clinical data including symptoms, signs, and imaging of 865 consecutive patients with aortic dissection were analyzed retrospectively. RESULTS: Neurological symptoms occurred in 225 cases (26.0%) with aortic dissection. The most common symptom was dizziness (56 cases, 6.5%), followed by syncope (49, 5.7%), single lower limb sensory disturbances (47, 5.4%), single lower extremity weakness (27, 3.1%), coma (22, 2.5%), paraplegia (19, 2.2%), headache (13,1.5%) and hemiplegia (9,1.0%). The first manifestation of five cases was the neurological symptoms, including syncope (2), dizziness (1) and headache (2). Patients with type A aortic dissection were more vulnerable to the neurological symptoms than those with type B aortic dissection (34.6% vs 14.7%), and the symptoms with significantly higher occurrence were syncope, coma, hemiplegia, paraplegia and lower limb sensory disturbances. CONCLUSION: Neurological symptoms are common in patients with aortic dissection,especially in those with type A aortic dissection.

Expression of endogenous beta retroviruses and Hyal-2 mRNA in immune organs of fetuses and lambs.

Endogenous beta retroviruses (enJSRV) are highly homologous with Jaagsiekte sheep retrovirus (exJSRV), this exogenous retrovirus is the aetiological agent of ovine pulmonary adenocarcinoma (OPA). The aim of this study was to clarify the function of enJSRV and the immunological mechanisms of its corresponding antibody, that is undetectable in JSRV-infected ovine serum. The expression of enJSRV envelope protein and Hyal-2 mRNA in immune organs and lungs of ovine fetuses and lambs were analyzed by Real-Time reverse transcription PCR and In Situ Hybridization using specific probes. In Situ Hybridization results indicated that the enJSRV envelope protein and Hyal-2 mRNA were expressed in thymus, spleen, mesenteric lymph nodes and lungs at different times, while no positive signals were detected in the negative controls. On the other hand, results from Real-Time reverse transcription PCR analysis showed that in 130d fetuses and 3d newborn lambs the enJSRV mRNA levels were much higher in organs associated with the immune system than that in lungs, especially in the thymus and spleen, but levels of Hyal-2 mRNA expression was not significantly different in all collected tissue. These results provided evidence from an immunology point of view to understand why the circulating antibodies against exJSRV are undetectable in JSRV-infected ovine, and will help to unravel the pathogenesis of JSRV-infected ovine.

[TH gene mutation in Chinese patients with autosomal recessive dopa-responsive dystonia].

OBJECTIVE: To explore the mutation of tyrosine hydroxylase(TH) gene in Chinese patients with autosomal recessive(AR) dopa-responsive dystonia(DRD) and to lay a solid basis for gene diagnosis of AR-DRD in China. METHODS: Mutation analysis of TH gene was performed in 5 probands with AR-DRD and 2 sporadic patients with DRD by use of polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) combining DNA direct sequencing. RESULTS: The PCR-SSCP analysis and DNA direct sequencing following PCR revealed no mutation in all the 14 exons of TH gene. CONCLUSION: The mutation rate of TH gene in Chinese patients with AR-DRD is low, hence suggesting the genetic heterogeneity and a new locus for AR-DRD.

Apolipoprotein H gene polymorphisms and risk of primary cerebral hemorrhage in a Chinese population.

BACKGROUND AND PURPOSE: Apolipoprotein H (ApoH) has been implicated in several physiologic pathways including lipid metabolism, coagulation and the production of hypertension, which are related to the pathogenesis of primary cerebral hemorrhage (PICH). The gene coding for ApoH is polymorphic, with the occurrence of several common alleles in the general population. This genetically determined variation can effect lipid metabolism and the production of hypertension. We determined the distribution of ApoH gene polymorphisms in Chinese people and investigated whether these polymorphisms were associated with increased risk of PICH in a Chinese population. METHODS: We studied polymorphisms of the ApoH gene by the polymerase chain reaction-single strand conformation polymorphism technique and DNA sequencing in 140 PICH patients and 100 healthy control subjects. Serum antiphospholipid antibodies and lipid levels were also examined in all subjects. RESULTS: Four polymorphisms of the ApoH gene have been identified in Chinese people. No difference in genotype frequencies of G817T (Leu247Val) polymorphism, G1025C (Try316Ser) polymorphism and C1080T polymorphism was observed between PICH patients and control subjects (p > 0.05). The G341A (Ser88Asn) polymorphism correlated significantly with PICH. The frequencies of the A allele were significantly higher in PICH patients than in controls, especially in PICH patients with hypertension and a family history of stroke. CONCLUSIONS: Our results suggest that the G341A (Ser88Asn) polymorphism might be associated with increased risk of PICH in a Chinese population. The association appeared to be mediated by the generation of hypertension.

[Lipoprotein (a) and cerebral infarction in young adults].

OBJECTIVE: To investigate the relation between lipoprotein (a) (LP(a)) and cerebral infarction in young adults. METHODS: Serum LP(a) of 90 young adults (age below 45 years) with cerebral infarction was measured. Serum lipids include triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol, low density lipoprotein cholesterol, apolipoprotein A-I (ApoA-I) and apolipoprotein B (ApoB) were also measured. Other possible risk factors such as hypertension, smoking, drinking and family stroke history were reviewed. RESULTS: There was no significant difference of serum LP(a) value between stroke patients and controls. TG (P < 0.01) and ApoB (P < 0.01) values in patients with cerebral infarction were significant higher than those in controls. Lipoprotein (a) was correlated with total cholesterol and low density lipoprotein cholesterol, with the values of correlation coefficient (r) 0.28 and 0.23 (both P < 0.01). After adjustment for age, sex, hypertension, smoking, drinking alcohol, family stroke history and other serum lipids, the odd radio for LP(a) and cerebral infarction was 0.74 (95% CI: 0.27 - 1.98). The odd radio for elevated TG was 3.57 (95% CI: 1.34 - 9.49); The odd ratios for hypertension, heart diseases and smoking as risk factors for cerebral infarction in young patients showed as: hypertension OR = 8.18, 95% CI: 2.54 - 26.33; heart diseases: OR = 8.51, 95% CI: 2.27 - 31.85; smoking: OR = 3.21, 95% CI: 1.27 - 8.13. CONCLUSION: LP(a) might not be a risk factor for cerebral infarction in young patients while elevated triglyceride, hypertension, heart diseases and smoking were important risk factors in young adults with cerebral infarction.