Rationale and design for comparison of non-compliant balloon with drug-coating balloon angioplasty for side branch after provisional stenting for patients with true coronary bifurcation lesions: a prospective, multicentre and randomised DCB-BIF trial.

INTRODUCTION: Provisional stenting using drug-eluting stent is effective for simple coronary bifurcation lesions. Kissing balloon inflation using conventional non-compliant balloon is the primary treatment of side branch (SB) after main vessel (MV) stenting. Drug-coating balloon (DCB) is reported to be associated with less frequent clinical events in in-stent restenosis and small vessel disease. The importance of DCB in bifurcation treatment is understudied. Accordingly, this trial is designed to investigate the superiority of DCB to non-compliant balloon angioplasty for SB after provisional stenting in patients with true coronary bifurcation lesions. METHODS AND ANALYSIS: The DCB-BIF trial is a prospective, multicentre, randomised, superiority trial including 784 patients with true coronary bifurcation lesions. Patients will be randomised in a 1:1 fashion to receive either DCB or non-compliant balloon angioplasty if SB diameter stenosis >70% after MV stenting. The primary endpoint is the composite of major adverse cardiac event at the 1-year follow-up, including cardiac death, myocardial infarction (MI) or clinically driven target lesion revascularisation. The major secondary endpoints include all-cause death, periprocedural MI, spontaneous MI, clinically driven target vessel revascularisation, in-stent restenosis, stroke and individual component of the primary endpoint. The safety endpoint is the risk of stent thrombosis. ETHICS AND DISSEMINATION: The study protocol and informed consent have been reviewed and approved by the Institutional Review Board of all participating centres. The written informed consent for participation in the trial will be obtained from all participants. The results of this study will be published in a peer-reviewed journal and disseminated at conferences. TRIAL REGISTRATION NUMBER: NCT04242134.

Risk factors for chronic hydrocephalus in patients with intracerebral hemorrhage complicated by coma after emergency hematoma removal.

Background: The cerebrospinal fluid circulation of patients with intracerebral hemorrhage (ICH) can be blocked by blood clots, resulting in acute hydrocephalus. However, current research on chronic hydrocephalus (CH) is lacking. Methods: A total of 253 patients with ICH combined with coma treated at The Third People's Hospital of Gansu Province after emergency hematoma removal from January 2018 to January 2020 were included. Patients were divided into the CH group (n=48) and the control group (n=205) depending on whether hydrocephalus occurred or not within 3-12 months after operation. The main clinical characteristics of the two groups were compared, and the risk factors for CH were analyzed. Counting data of the two groups were expressed as "n (%)", and multivariate logistic regression analysis was used to explore the risk factors for CH. Results: Compared with the control group, the proportion of patients with modified Graeb score ≥5 points in the CH group increased significantly (52.08% vs. 21.95%, P=0.000). The proportion of patients with preoperative cerebral hernia increased significantly (37.5% vs. 19.51%, P=0.008). The proportion of patients with preoperative obstructive hydrocephalus increased (43.75% vs. 24.39%, P=0.007). The proportion of patients with postoperative subdural effusion increased (41.67% vs. 13.66%, P=0.000). Multivariate logistic regression analysis showed that a modified Graeb score ≥5 points and postoperative subdural effusion were risk factors for the formation of CH in patients with ICH complicated by coma after emergency hematoma removal (P<0.05). The modified Graeb score has diagnostic value for the formation of CH in patients with ICH combined with coma after emergency hematoma removal, and the area under the curve was 0.653 [P=0.001, 95% confidence interval (CI): 0.561-0.744]. There was no significant difference in preoperative neurological deficit score between the control group and the CH group (19.75±3.03 vs. 19.86±3.01, P=0.113). Compared with the control group, the neurological deficit score at 12 months after operation in the CH group was significantly higher (12.73±2.99 vs. 10.64±2.82, P=0.000). Conclusions: A modified Graeb score >5 points and postoperative subdural effusion are risk factors for the formation of CH in patients with ICH combined with coma after emergency hematoma removal. The formation of CH affects postoperative neurological rehabilitation.

ARB might be superior to ACEI for treatment of hypertensive COVID-19 patients.

The administration of ACEI/ARB (angiotensin-converting enzyme inhibitors/Angiotension II receptor blockers) in COVID-19 (coronavirus disease 2019) patients with hypertension exhibits a lower risk of mortality compared with ACEI/ARB non-users. In this context, an important question arises: is ACEI or ARB more suitable for the treatment of hypertensive COVID-19 patients? Taken into consideration the following four rationales, ARB may offer a more significant benefit than ACEI for the short-term treatment of hypertensive COVID-19 patients: 1. ACEI has no inhibition on non-ACE-mediated Ang II production under infection conditions, whereas ARB can function properly regardless of how Ang II is produced; 2. ACEI-induced bradykinin accumulation may instigate severe ARDS while ARB has no effects on kinin metabolism; 3. ARB alleviates viscous sputa production and inflammatory reaction significantly in contrast to ACEI; 4. ARB may attenuate the lung fibrosis induced by mechanical ventilation in severe patients and improve their prognosis significantly compared with ACEI. To examine the advantages of ARB over ACEI on hypertensive COVID-19 patients, retrospective case-control studies comparing the clinical outcomes for COVID-19 patients receiving ARB or ACEI treatment is strikingly needed in order to provide guidance for the clinical application.

Epidemiologically characteristics of human brucellosis and antimicrobial susceptibility pattern of Brucella melitensis in Hinggan League of the Inner Mongolia Autonomous Region, China.

BACKGROUND: Hinggan League is located in the Northeast of the Inner Mongolia Autonomous Region, the historically endemic area of animal and human brucellosis. In this study, the epidemiological characteristics of human brucellosis were analyzed, and the genotypic profile and antimicrobial susceptibilities of Brucella melitensis strains isolated from humans in Hinggan League were investigated. METHODS: The epidemic characteristics were described using case number, constituent ratio, and rate. The 418 human blood samples were collected and tested by bacteriology, and suspect colonies were isolated and identified by conventional biotyping assays, the VITEK 2.0 microbial identification system, and AMOS (Brucella abortus, B. melitensis, B. ovis, and B. suis)-PCR. Subsequently, all strains were genotyped using multiple-locus variable-number tandem repeat analysis (MLVA) assays, and the antimicrobial susceptibility pattern of Brucella strains against the 10 most commonly used antibiotics was determined by microdilution method. RESULTS: A total of 22 848 cases of human brucellosis were reported from 2004 to 2019, with an annual average incidence of 87.2/100 000. The incidence rates in developed areas of animal husbandry (Horqin Youyi Qianqi [161.2/100 000] and Horqin Youyi Zhongqi [112.1/100 000]) were significantly higher than those in forest areas (Arxan [19.2/100 000]) (χ2 = 32.561, P < 0.001). In addition, peak morbidity occurred during May-August, accounting for 72.6% (16582/22 848) of cases. The highest number of cases occurred in the 40+ age group, accounting for 44.4% (10 137/22484) of cases, and morbidity in males was significantly higher than that in females in all age groups (χ2 = 299.97, P < 0.001), the most common occupation was farmers. A total of 54 B. melitensis strains were divided into 37 genotypes (GT1-37) with 80-100% genetic similarity. All 25 strains were sensitive to seven tested antibiotics, phenotypic resistance to cotrimoxazole and azithromycin was observed in 5 (20%) and 25 (100%) of the isolates, respectively. CONCLUSIONS: Human brucellosis exhibited a significant increasing trend and B. melitensis is the main pathogen responsible for human brucellosis in this region. Improved surveillance of infected animals (sheep) and limiting their transfer and trade are optional strategies for decreasing the incidence of this disease.

A New Zn(II)-containing Coordination Polymer for Photocatalytic Degradation of Organic Dyes and Treatment Activity on Atherosclerosis via Reducing the Vcam-1 Expression.

By employment of a rigid tripodal nitrogen-containing heterotopic ligand tris(1-imidazolyl) benzene (Htib), a new fluorescent Zn(II)-containing coordination polymer {[Zn(tib)2](NO3)2(H2O)3}n (1) with a rare two-fold interpenetrating (3,6)-connected pyr network topology has been successfully prepared under the solvothermal reaction conditions. Under the condition of visible light irradiation, rhodamine B (RhB) and methylene blue (MB) could be degraded with good performance. In the biological function study, the cytotoxicity of the synthetic was evaluated with CCK-8 detection kit on human umbilical vein endothelial cells (HUVEC). The inhibitory effect of compound on vcam-1 expression in the vascular endothelial cells was evaluated by RT-PCR. The effect of the complex on the inflammatory response in the vascular endothelial cells was determined via ELISA test of IL-1ß and TNF-α. The results of pose scoring software as well as molecular docking was conducted to explore the interaction between compounds and VCAM, which might provide latent regulatory mechanisms along with binding sites for compounds.

[Effect of Ginkgo biloba Tablet on the Expression of Scavenger Receptor A of the Aortic Wall in Atherosclerotic Rats].

OBJECTIVE: To observe the expression of Ginkgo biloba Tablet (GbT) on scavenger receptor A (SRA) of the aortic wall and changes of serum inflammatory factors in atherosclerotic rats, and to explore its new mechanism for fighting against atherosclerosis (AS). METHODS: Totally 45 male Wistar rats were randomly divided into the control group, the model group, the GbT group, 15 rats in each group. Levels of blood glucose, blood lipids, blood calcium, serum C-reactive protein (CRP), soluble intercellular adhesion molecule-1 (slCAM-1), and soluble vascular cell adhesion molecule-1 (sVCAM-1) were measured in all rats. The expression of SRA in the aortic wall of atherosclerotic rats was observed by immunohistochemical assay. The correlation between the expression of SRA and levels of in-flammatory factors was also observed. RESULTS: Compared with the control group, blood glucose and blood calcium obviously increased (P < 0.05); levels of TG, TC, and LDL-C were significantly elevated (P < 0.01); neointimal areas were significantly thickened, increased intima percentage was significantly enlarged, narrowed lumen index was significantly reduced; levels of CRP, sICAM-1, and sVCAM-1 were significantly elevated in the model group (all P < 0.01). Compared with the model group, blood glucose and blood calcium obviously decreased (P < 0.05); levels of TG, TC, and LDL-C significantly decreased (P < 0.01) in the GbT group. Aortic lumens were obviously narrower in the model group than in the GbT group (P < 0.05). SRA expressed at the aortic wall. The aforesaid 3 indices were significantly improved in the GbT group than in the model group (P < 0.01). Serum levels of CRP, sICAM-1, and sVCAM-1 were significantly decreased in the GbT group than in the model group (P < 0.01). Serum levels of CRP, sICAM-1, and sVCAM-1 were positively correlated with the percentage of SRA positive expression area (r = 0.701, 0.604, 0.581, all P < 0.01). CONCLUSIONS: Serum levels of inflammatory factors in atherosclerotic rats were elevated, and the expression of SRA in the aortic wall was enhanced. The expression of SRA was closely correlated with serum levels of inflammatory factors. GbT could decrease serum levels of inflammatory factors and inhibit the expression of SRA.

Functional thyrotropin receptor expression in the ventricle and the effects on ventricular BNP secretion.

Elevated thyrotropin (TSH) and hypercholesterolemia commonly coexist in patients with subclinical hypothyroidism, which can cause and aggravate heart disease. However, it is unclear whether TSH has a direct effect on cardiac function. To determine the expression of the thyrotropin receptor (TSHR) and the effects of TSH on ventricular function, we analyzed the ventricular tissues and thyroid glands from normal rats and mice and the H9c2 cardiomyocyte cell line. The results revealed that TSHR was expressed at the transcriptional and protein levels by PCR, immunoblotting, immunohistochemistry and immunofluorescence. The mRNA levels of ß-MHC and the expression of pCREB and HMGCR in the ventricle were significantly lower in Tshr (-/-) mice than in wild-type (WT) mice (p < 0.05), but serum NT-proBNP levels were similar between WT and Tshr (-/-) mice. After synchronization, H9c2 cells were stimulated with several concentrations of TSH for various time periods. TSH up-regulated ß-MHC mRNA expression in H9c2 cells. Cyclic adenosine monophosphate (cAMP) production and downstream signaling, such as pCREB and HMGCR expression and NT-proBNP secretion, increased in dose- and time-dependent manners. The TSH-stimulated effects were suppressed by an adenylyl cyclase inhibitor, a protein kinase A (PKA) inhibitor and HMGCR inhibitors (all p < 0.05). The data indicate functional TSHR is expressed in ventricular myocytes and mediates TSH-induced BNP secretion and HMGCR up-regulation through the cAMP/PKA/pCREB signaling pathway. Our findings suggest a potentially novel pathophysiological role of TSH in heart failure-associated hypothyroidism.

[Salvia Miltiorrhiza reduces plasma levels of asymmetric ADMA in patients with non-ST elevation myocardial infarction undergoing percutaneous coronary intervention].

OBJECTIVE: To study changes of plasma ADMA levels of patients with non-ST elevation myocardial infarction (NSTEMI) undergoing percutaneous coronary intervention (PCI) and to explore the effect of Salvia Miltiorrhiza (SM) on them. METHODS: Totally 52 patients with confirmed NSTEMI undergoing PCI were randomly assigned to the SM treated group and the control group, 26 in each group. Patients in the SM treated group received the conventional therapy plus SM (1 g each time, three times per day till one month after PCI). Those in the control group only received the conventional therapy. Plasma ADMA levels were measured before PCI, and at day 1 and 30 after PCI. RESULTS: Plasma ADMA levels in both group obviously decreased at day 30 after PCI with statistical difference (P < 0.01). The decrement was more obviously seen in the SM treated group, with statistical difference when compared with the control group (P < 0.01). CONCLUSIONS: Patients with NSTEMI undergoing PCI could have plasma ADMA levels decreased. Administration of SM just before PCI might be associated with negative regulating plasma ADMA levels.

Association of SIRT1 expression with shear stress induced endothelial progenitor cell differentiation.

Shear stress imposed by blood flow is crucial for differentiation of endothelial progenitor cells (EPCs). Histone deacetylase SIRT1 has been shown to play a pivotal role in many physiological processes. However, association of SIRT1 expression with shear stress-induced EPC differentiation remains to be elucidated. The present study was designed to determine the effect of SIRT1 on EPC differentiation induced by shear stress, and to seek the underlying mechanisms. Human umbilical cord blood-derived EPCs were exposed to laminar shear stress of 15 dyn/cm(2) by parallel plate flow chamber system. Shear stress enhanced EPC differentiation toward endothelial cells (ECs) while inhibited to smooth muscle cells (SMCs). The expressions of phospho-Akt, SIRT1 and histone H3 acetylation (Ac-H3) in EPCs were detected after exposure to shear stress for 2, 6, 12, and 24 h, respectively. Shear stress significantly activated Akt phosphorylation, augmented SIRT1 expression and downregulated Ac-H3. SIRT1 siRNA in EPCs diminished the expression of EC markers, but increased the expression of SMC markers, and resulted in upregulation of Ac-H3. Whereas, resveratrol, an activator of SIRT1, had the opposite effects on both EPC differentiation and histone H3 acetylation. Wortmannin, an inhibitor of PI3-kinase, suppressed endothelial differentiation of EPCs, decreased SIRT1, and upregulated Ac-H3 expression. In addition, SIRT1 promoted tube formation of EPCs in matrix gels. These results provided a mechanobiological basis of shear stress-induced EPC differentiation into ECs and suggest that PI3k/Akt-SIRT1-Ac-H3 pathway is crucial in such a process.

[Cardiac metallothionein overexpression improves cardiac contractile function and attenuates oxidative stress in lipopolysaccharide-treated mice].

OBJECTIVE: This study was designed to examine the impact of the antioxidant metallothionein (MT) on cardiac contractile, intracellular Ca(2+) function and oxidative stress in lipopolysaccharide (LPS)-treated mice. METHODS: Weight and age matched adult male FVB and cardiac-specific MT-overexpressing transgenic mice were injected intraperitoneally with 4 mg/kg Escherichia Coli LPS dissolved in sterile saline or an equivalent volume of pathogen-free saline (control groups). Six hours following LPS or saline injection, cardiac geometry and function were evaluated in anesthetized mice using the 2-D guided M-mode echocardiography. Mechanical and intracellular Ca(2+) properties were examined in hearts. Cell shortening and relengthening were assessed using the following indices: peak shortening (PS)-indicative of the amplitude a cell can shorten during contraction; maximal velocities of cell shortening and relengthening (± dl/dt)-indicative of peak ventricular contractility; time-to-PS (TPS)-indicative of systolic duration; time-to-90% relengthening (TR(90))-indicative of diastolic duration (90% rather 100% relengthening was used to avoid noisy signal at baseline concentration). The 360 nm excitation scan was repeated at the end of the protocol and qualitative changes in intracellular Ca(2+) concentration were inferred from the ratio of fura-2 fluorescence intensity (FFI) at two wavelengths (360/380). Fluorescence decay time was measured as an indicator of the intracellular Ca(2+) clearing rate. Glutathione/glutathione disulfide ratio and ROS generation were detected as the markers of oxidative stress. RESULTS: Heart rate was increased while EF was reduced in LPS-FVB mice and heart rate was reduced and EF increased in MT-LPS transgenic mice [(528 ± 72) beats/min vs (557 ± 69) beats/min, (66 ± 14)% vs (42 ± 10)%, P < 0.05]. Cardiomyocytes from the LPS treated FVB mice displayed significantly reduced peak shortening (PS) and maximal velocity of shortening/relengthening (±dl/dt) associated with prolonged time-to-90% relengthening (TR(90)), these effects were attenuated in cardiomyocytes from the MT-LPS mice [PS(5 ± 1.1)% vs (7.2 ± 0.8)%, dl/dt(160 ± 15) µm/s vs (212 ± 36) µm/s, -dl/dt (175 ± 32) µm/s vs (208 ± 29) µm/s, TR(90) (0.24 ± 0.03)s vs (0.19 ± 0.02)s, P < 0.05]. LPS treated mice showed significantly reduced peak intracellular Ca(2+) and electrically-stimulated rise in intracellular Ca(2+) as well as prolonged intracellular Ca(2+) decay rate without affecting the basal intracellular Ca(2+) levels, again, these effects were significantly attenuated in MT-LPS transgenic mice. Metallothionein overexpression also ablated oxidative stress [reduced ROS generation and increased glutathione/glutathione disulfide ratio, ROS (0.35 ± 0.08) A/µg protein vs (0.24 ± 0.03) A/µg protein]. GSH/GSSG 2.1 ± 0.2 vs 2.6 ± 0.4, P < 0.05. CONCLUSION: MT overexpression improved cardiac function and ablated oxidative stress in LPS treated mice.

Study of embryotoxicity of Fusarium mycotoxin butenolide using a whole rat embryo culture model.

Butenolide, a mycotoxin elaborated by several toxigenic Fusarium species, has been implicated as an etiological factor of Kashin-Beck disease and it is always detected in food from endemic Kashin-Beck disease areas. Although butenolide is considered as a potential health risk to humans and animals, its toxicity targets and mechanism of action have not been fully understood and the knowledge of its developmental toxicity is absent. The present study investigated butenolide embryotoxicity via an in vitro whole embryo culture system using rat embryos. Embryos exposed to butenolide at a concentration of 0.625 mg/L showed and differentiation similar to that of the control embryos (=no observed adverse effect concentration; NOAECwec). The embryonic growth and differentiation were affected, represented as reduced crown-rump length and head length, and decreased number of somites from 1.25 mg/L. Total morphological scores decreased significantly at the concentration of butenolide of 2.5 mg/L. All embryos were malformed at 3.75 mg/L and above (=ICMaxWEC), presenting growth retardation with flexion failure and irregular somite differentiation. The IC503T3 of butenolide as calculated from the balb/c 3T3 cytotoxicity test is 6.45 mg/L. Our study shows that butenolide exerts detrimental effects on embryo development in vitro by inducing growth retardation and differentiation inhibition, and the embryotoxicity effect of butenolide should be treated with caution.

Soluble erythropoietin receptor contributes to erythropoietin resistance in end-stage renal disease.

BACKGROUND: Erythropoietin is a growth factor commonly used to manage anemia in patients with chronic kidney disease. A significant clinical challenge is relative resistance to erythropoietin, which leads to use of successively higher erythropoietin doses, failure to achieve target hemoglobin levels, and increased risk of adverse outcomes. Erythropoietin acts through the erythropoietin receptor (EpoR) present in erythroblasts. Alternative mRNA splicing produces a soluble form of EpoR (sEpoR) found in human blood, however its role in anemia is not known. METHODS AND FINDINGS: Using archived serum samples obtained from subjects with end stage kidney disease we show that sEpoR is detectable as a 27kDa protein in the serum of dialysis patients, and that higher serum sEpoR levels correlate with increased erythropoietin requirements. Soluble EpoR inhibits erythropoietin mediated signal transducer and activator of transcription 5 (Stat5) phosphorylation in cell lines expressing EpoR. Importantly, we demonstrate that serum from patients with elevated sEpoR levels blocks this phosphorylation in ex vivo studies. Finally, we show that sEpoR is increased in the supernatant of a human erythroleukaemia cell line when stimulated by inflammatory mediators such as interleukin-6 and tumor necrosis factor alpha implying a link between inflammation and erythropoietin resistance. CONCLUSIONS: These observations suggest that sEpoR levels may contribute to erythropoietin resistance in end stage renal disease, and that sEpoR production may be mediated by pro-inflammatory cytokines.

Angiopoietin 2 is a partial agonist/antagonist of Tie2 signaling in the endothelium.

Angiopoietin 2 (Ang2) was originally shown to be a competitive antagonist for Ang1 of the receptor tyrosine kinase Tie2 in endothelial cells (ECs). Since then, reports have conflicted on whether Ang2 is an agonist or antagonist of Tie2. Here we show that Ang2 functions as an agonist when Ang1 is absent but as a dose-dependent antagonist when Ang1 is present. Exogenous Ang2 activates Tie2 and the promigratory, prosurvival PI3K/Akt pathway in ECs but with less potency and lower affinity than exogenous Ang1. ECs produce Ang2 but not Ang1. This endogenous Ang2 maintains Tie2, phosphatidylinositol 3-kinase, and Akt activities, and it promotes EC survival, migration, and tube formation. However, when ECs are stimulated with Ang1 and Ang2, Ang2 dose-dependently inhibits Ang1-induced Tie2 phosphorylation, Akt activation, and EC survival. We conclude that Ang2 is both an agonist and an antagonist of Tie2. Although Ang2 is a weaker agonist than Ang1, endogenous Ang2 maintains a level of Tie2 activation that is critical to a spectrum of EC functions. These findings may reconcile disparate reports of Ang2's effect on Tie2, impact our understanding of endogenous receptor tyrosine kinase signal transduction mechanisms, and affect how Ang2 and Tie2 are targeted under conditions such as sepsis and cancer.

Receptor tyrosine kinase Tie-1 overexpression in endothelial cells upregulates adhesion molecules.

Tie-1 is an endothelial specific cell surface protein whose biology remains poorly understood. Using an overexpression system in vitro, we examined whether Tie-1 activity in endothelial cells in vitro would elicit a proinflammatory response. We found that when overexpressed in endothelial cells in vitro, Tie-1 is tyrosine-phosphorylated. We also showed that Tie-1 upregulates VCAM-1, E-selectin, and ICAM-1, partly through a p38-dependent mechanism. Interestingly, upregulation of VCAM-1 and E-selectin by Tie-1 is significantly higher in human aortic endothelial cells than in human umbilical vein endothelial cells. Additionally, attachment of cells of monocytic lineage to endothelial cells is also enhanced by Tie-1 expression. Collectively, our data show that Tie-1 has a proinflammatory property and may play a role in the endothelial inflammatory diseases such as atherosclerosis.

Activation of the orphan endothelial receptor Tie1 modifies Tie2-mediated intracellular signaling and cell survival.

A critical role for Tie1, an orphan endothelial receptor, in blood vessel morphogenesis has emerged from mutant mouse studies. Moreover, it was recently demonstrated that certain angiopoietin (Ang) family members can activate Tie1. We report here that Ang1 induces Tie1 phosphorylation in endothelial cells. Tie1 phosphorylation was, however, Tie2 dependent because 1) Ang1 failed to induce Tie1 phosphorylation when Tie2 was down-regulated in endothelial cells; 2) Tie1 phosphorylation was induced in the absence of Ang1 by either a constitutively active form of Tie2 or a Tie2 agonistic antibody; 3) in HEK 293 cells Ang1 phosphorylated a form of Tie1 without kinase activity when coexpressed with Tie2, and Ang1 failed to phosphorylate Tie1 when coexpressed with kinase-defective Tie2. Ang1-mediated AKT and 42/44MAPK phosphorylation is predominantly Tie2 mediated, and Tie1 down-regulates this pathway. Finally, based on a battery of in vitro and in vivo data, we show that a main role for Tie1 is to modulate blood vessel morphogenesis by virtue of its ability to down-regulate Tie2-driven signaling and endothelial survival. Our new observations help to explain why Tie1 null embryos have increased capillary densities in several organ systems. The experiments also constitute a paradigm for how endothelial integrity is fine-tuned by the interplay between closely related receptors by a single growth factor.

Immune tolerance to cardiac myosin induced by anti-CD4 monoclonal antibody in autoimmune myocarditis rats.

Autoimmune myocarditis is a T-cell-mediated autoimmune disease. CD4-positive T cells are believed to be the most important for the initiation and mediation of the disease. This study was aimed at evaluating whether anti-CD4 monoclonal antibody could induce immune tolerance to porcine cardiac myosin and whether the immune tolerance could protect rats with autoimmune myocarditis from myocardial injury. Lewis rats were immunized with porcine cardiac myosin to induce experimental autoimmune myocarditis. Immune tolerance was induced by injections of anti-CD4 monoclonal antibody on days -2, -1, 0, and 1. Results showed that cardiac function of antibody-treated rats was significantly increased compared with untreated rats 18 days postimmunization examined by transthoracic echocardiography. Typical cardiac histopathological changes were observed obviously in untreated group but not in antibody-treated group. Lymphocytes obtained from antibody-treated group had no proliferative response to porcine cardiac myosin examined by lymphocyte proliferation assay. Serological examination showed that rats immunized with cardiac myosin could produce high levels of anti-cardiac myosin antibody. The administration of anti-CD4 monoclonal antibody significantly prevented the increase of them. Serum levels of Th1 cytokines were significantly down-regulated by antibody administration, while the production of Th2 cytokines were up-regulated or unaffected evaluated by enzyme-linked immunosorbent assay. It concluded that immune tolerance to porcine cardiac myosin could be induced by anti-CD4 monoclonal antibody in vivo, and cardiac dysfunction and myocardial injury could be prevented by induction of immune tolerance.

Soluble endoglin contributes to the pathogenesis of preeclampsia.

Preeclampsia is a pregnancy-specific hypertensive syndrome that causes substantial maternal and fetal morbidity and mortality. Maternal endothelial dysfunction mediated by excess placenta-derived soluble VEGF receptor 1 (sVEGFR1 or sFlt1) is emerging as a prominent component in disease pathogenesis. We report a novel placenta-derived soluble TGF-beta coreceptor, endoglin (sEng), which is elevated in the sera of preeclamptic individuals, correlates with disease severity and falls after delivery. sEng inhibits formation of capillary tubes in vitro and induces vascular permeability and hypertension in vivo. Its effects in pregnant rats are amplified by coadministration of sFlt1, leading to severe preeclampsia including the HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome and restriction of fetal growth. sEng impairs binding of TGF-beta1 to its receptors and downstream signaling including effects on activation of eNOS and vasodilation, suggesting that sEng leads to dysregulated TGF-beta signaling in the vasculature. Our results suggest that sEng may act in concert with sFlt1 to induce severe preeclampsia.

Excess circulating angiopoietin-2 may contribute to pulmonary vascular leak in sepsis in humans.

BACKGROUND: Acute respiratory distress syndrome (ARDS) is a devastating complication of numerous underlying conditions, most notably sepsis. Although pathologic vascular leak has been implicated in the pathogenesis of ARDS and sepsis-associated lung injury, the mechanisms promoting leak are incompletely understood. Angiopoietin-2 (Ang-2), a known antagonist of the endothelial Tie-2 receptor, was originally described as a naturally occurring disruptor of normal embryonic vascular development otherwise mediated by the Tie-2 agonist angiopoietin-1 (Ang-1). We hypothesized that Ang-2 contributes to endothelial barrier disruption in sepsis-associated lung injury, a condition involving the mature vasculature. METHODS AND FINDINGS: We describe complementary human, murine, and in vitro investigations that implicate Ang-2 as a mediator of this process. We show that circulating Ang-2 is significantly elevated in humans with sepsis who have impaired oxygenation. We then show that serum from these patients disrupts endothelial architecture. This effect of sepsis serum from humans correlates with measured Ang-2, abates with clinical improvement, and is reversed by Ang-1. Next, we found that endothelial barrier disruption can be provoked by Ang-2 alone. This signal is transduced through myosin light chain phosphorylation. Last, we show that excess systemic Ang-2 provokes pulmonary leak and congestion in otherwise healthy adult mice. CONCLUSIONS: Our results identify a critical role for Ang-2 in disrupting normal pulmonary endothelial function.

Angiogenic factors in the pathogenesis of preeclampsia.

Preeclampsia affects 5-10% of pregnancies and is responsible for substantial maternal and neonatal morbidity and mortality. It is believed to be a two-stage disease with an initial placental trigger with no maternal symptoms followed by a maternal syndrome characterized by hypertension, proteinuria, and endothelial dysfunction. The first stage is thought to be due to shallow cytotrophoblast invasion of maternal spiral arterioles leading to placental insufficiency. The diseased placenta in turn releases soluble angiogenic factors that induce systemic endothelial dysfunction and clinical preeclampsia during the second stage. This review will discuss the role of circulating angiogenic factors of placental origin as potential mediators of the systemic endothelial dysfunction and the clinical syndrome of preeclampsia and provide an evolutionary explanation for this phenomenon.