Description: Background— Two endophenotypes of arterial calcification, calcification on arterial wall and calcification in atherosclerotic plaques, are associated with different types of cardiovascular events. Mgp -deficient mice showed matrix Gla protein (MGP) is strongly associated with calcification on arterial wall without atherosclerotic plaques, and MGP variants were not significantly associated with myocardial infarction. MGP may play different roles in the 2 endophenotypes. Methods and Results— We analyzed the associations of MGP variants rs4236, rs1800801, and rs1800802 with the 2 endophenotypes determined by multidetector computed tomography angiography. A total of 585 with calcification on coronary artery wall, 675 with calcification in coronary atherosclerotic plaques, 454 with calcification on aortic wall, and 725 controls were enrolled. After Bonferroni correction, rs4236 and rs1800801 were still associated with calcification on arterial wall, the odds ratios were 0.708 (95% confidence interval, 0.540–0.928) for rs4236 and 0.652 (95% confidence interval, 0.479–0.888) for rs1800801 in coronary artery wall calcification, and 0.699 (95% confidence interval, 0.525–0.931) for rs4236 and 0.650 (95% confidence interval, 0.467–0.905) for rs1800801 in aortic wall calcification, respectively. The variants were correlated with calcification severity by ln(CAC Agatston score+1) in coronary artery wall calcification but not in atherosclerotic plaque calcification. In accordance with their associations with calcification on arterial wall, rs4236C and rs1800801A were associated with higher MGP plasma levels, whereas rs1800802C was associated with lower MGP levels in normal controls. Because of the role of calcification in plaque vulnerability, their associations with acute myocardial infarction were also determined in 771 controls and 752 patients, no association was found. Conclusions— MGP genetic variants showed association with calcification on arterial wall but not with calcification in atherosclerotic plaques.

Description: Interferon regulatory factor 1 (IRF1), a critical member of the IRF family, was previously shown to be associated with the immune system and to be involved in apoptosis and tumor suppression. However, the role of IRF1 in pressure overload–induced cardiac remodeling has remained unclear. Using genetic approaches, we established a central role for the IRF1 transcription factor in the regulation of cardiac remodeling both in vivo and in vitro, and we determined the mechanism underlying this process. The expression level of IRF1 was remarkably altered in both failing human hearts and hypertrophic murine hearts. Transgenic mice with cardiac-specific IRF1 overexpression exacerbated aortic banding–induced cardiac hypertrophy, ventricular dilation, fibrosis, and dysfunction, whereas IRF1-deficient (knockout) mice exhibited a significant reduction in the hypertrophic response. Similar results were observed in a global IRF1-knockout rat model. Mechanistically, the prohypertrophic effects elicited by IRF1 in response to pathological stimuli were associated with the direct activation of inducible nitric oxide synthase (iNOS). Furthermore, we identified 1 IRF1-binding site in the promoter region of the iNOS gene, which was essential for its transcription. To examine the IRF1-iNOS axis in vivo, we generated IRF1-transgenic/iNOS-knockout mice. IRF1 exerted profoundly detrimental effects in these mice; however, these effects were nullified by iNOS ablation. These data suggest the IRF1–iNOS axis as a crucial regulator of cardiac remodeling and that IRF1 could be a potent therapeutic target for cardiac remodeling.

Description: Caspase recruitment domain 6 (CARD6), a crucial member of the CARD family, was initially shown to be involved in the immune system and oncogenesis. However, the role of CARD6 in chronic pressure overload–induced cardiac hypertrophy remains unexplored. To evaluate the impact of CARD6 on pathological cardiac hypertrophy, cardiac-specific CARD6 knockout mice and transgenic mice with cardiac-specific CARD6 overexpression were generated and subjected to aortic banding for 4 weeks. Our results demonstrated that CARD6-deficient mice aggravated aortic banding–triggered cardiac hypertrophy, ventricular dilation, fibrosis, and dysfunction, as measured by echocardiography, immunostaining, and molecular/biochemical analyses. Conversely, CARD6-overexpressing mice exhibited an attenuated hypertrophic response to chronic pressure overload. Similarly, using cultured neonatal rat cardiomyocytes, we found that adenovirus vector–driven overexpression of CARD6 dramatically limited angiotensin II–induced myocyte hypertrophy, whereas knockdown of CARD6 by AdshCARD6 (adenoviral short hairpin CARD6) exhibited the opposite phenotypes. Furthermore, analysis of the signaling events in vitro and in vivo revealed that CARD6-mediated protection against cardiac hypertrophy was attributed to the interruption of mitogen-activated protein kinase kinase (MEK) kinase-1–dependent MEK-extracellular signal-regulated protein kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase 1/2 (JNK1/2) activation. Altogether, these data indicated that CARD6 serves as a novel cardioprotective factor via negative regulation of MEK kinase-1–dependent MEK-ERK1/2 and JNK1/2 signaling. Thus, our study suggests that CARD6 may be a novel target for the treatment of pathological cardiac hypertrophy and failure.

Description: Siglecs are sialic acid-binding Ig-like lectins that recognize sialoglycans via amino-terminal V-set domains. CD33-related Siglecs (CD33rSiglecs) on innate immune cells recognize endogenous sialoglycans as "self-associated molecular patterns" (SAMPs), dampening immune responses via cytosolic immunoreceptor tyrosine-based inhibition motifs that recruit tyrosine phosphatases. However, sialic acid-expressing pathogens subvert this mechanism through molecular mimicry. Meanwhile, endogenous host SAMPs must continually evolve to evade other pathogens that exploit sialic acids as invasion targets. We hypothesized that these opposing selection forces have accelerated CD33rSiglec evolution. We address this by comparative analysis of major CD33rSiglec (Siglec-3, Siglec-5, and Siglec-9) orthologs in humans, chimpanzees, and baboons. Recombinant soluble molecules displaying ligand-binding domains show marked quantitative and qualitative interspecies differences in interactions with strains of the sialylated pathogen, group B Streptococcus , and with sialoglycans presented as gangliosides or in the form of sialoglycan microarrays, including variations such as N -glycolyl and O -acetyl groups. Primate Siglecs also show quantitative and qualitative intra- and interspecies variations in expression patterns on leukocytes, both in circulation and in tissues. Taken together our data explain why the CD33rSiglec-encoding gene cluster is undergoing rapid evolution via multiple mechanisms, driven by the need to maintain self-recognition by innate immune cells, while escaping 2 distinct mechanisms of pathogen subversion.—Padler-Karavani, V., Hurtado-Ziola, N., Chang, Y.-C., Sonnenburg, J. L., Ronaghy, A., Yu, H., Verhagen, A., Nizet, V., Chen, X., Varki, N., Varki, A., Angata, T. Rapid evolution of binding specificities and expression patterns of inhibitory CD33-related Siglecs in primates.

Description: Background and Purpose— The Tada (ABC/2) formula has been used widely for volume assessment of intracerebral hematoma. However, the formula is crude for irregularly shaped hematoma. We aimed to compare the accuracy of the ABC/2 formula with open source software Slicer. Methods— Computed tomographic images of 294 patients with spontaneous intracerebral hematoma were collected. Hematoma volumes were assessed with the ABC/2 formula and calculated with software 3D Slicer. Results of these 2 methods were compared with regard to hematoma size and shape. Results— The estimated hematoma volume was 58.41±37.83 cm 3 using the ABC/2 formula, compared with 50.38±31.93 cm 3 with 3D Slicer (mean percentage deviation, 16.38±9.15%). When allocate patients into groups according to hematoma size, the mean estimation error were 3.24 cm 3 (17.72%), 5.85 cm 3 (13.72%), and 15.14 cm 3 (17.48%) for groups 1, 2, and 3, respectively. When divided by shape, estimation error was 3.33 cm 3 (9.76%), 7.19 cm 3 (18.37%), and 29.39 cm 3 (39.12%) for regular, irregular, and multilobular hematomas. Conclusions— There is significant estimation error using the ABC/2 formula to calculate hematoma volume. Compared with hematoma size, estimation error is more significantly associated with hematoma shape.

Description: Background and Purpose— By 2010 there had been 14 published trials of surgery for intracerebral hemorrhage reported in systematic reviews or to the authors, but the role and timing of operative intervention remain controversial and the practice continues to be haphazard. This study attempted to obtain individual patient data from each of the 13 studies published since 1985 to better define groups of patients that might benefit from surgery. Methods— Authors of identified published articles were approached by mail, e-mail, and at conferences and invited to take part in the study. Data were obtained from 8 studies (2186 cases). Individual patient data included patient's age, Glasgow Coma Score at presentation, volume and site of hematoma, presence of intraventricular hemorrhage, method of evacuation, time to randomization, and outcome. Results— Meta-analysis indicated that there was improved outcome with surgery if it was undertaken within 8 hours of ictus ( P =0.003), or the volume of the hematoma was 20 to 50 mL ( P =0.004), or the Glasgow Coma Score was between 9 and 12 ( P =0.0009), or the patient was aged between 50 and 69 years ( P =0.01). In addition, there was some evidence that more superficial hematomas with no intraventricular hemorrhage might also benefit ( P =0.09). Conclusions— There is evidence that surgery is of benefit if undertaken early before the patient deteriorates. This work identifies areas for further research. Ongoing studies in subgroups of patients such as the Surgical Trial in Lobar Intracerebral Hemorrhage (STICH II) will confirm whether these interpretations can be replicated.

Description: A novel tick-borne bunyavirus (Huaiyangshan virus, HYSV), which causes haemorrhagic fever-like disease, has recently been reported in China. So far no animal experiments have been performed to study its pathogenesis. Towards developing an animal model for HYSV fever, newborn and adult mice and rats and golden hamsters were inoculated intracerebrally or intraperitoneally with HYSV. Newborn rats and newborn mice, especially Kunming (KM) mice, appeared highly susceptible. Remarkably, the KM mice that died of the HYSV infection developed large necrotic areas in the liver, while no obvious pathological changes were observed within the other organs. PCR and immunohistochemical analyses of the post-mortem material detected both HYSV antigen and RNA in almost all organs, indicating a systemic infection. Our data demonstrate that HYSV can cause a lethal infection of both newborn mice and newborn rats with apparent pathological damage of the liver. This animal model may help to understand the pathogenesis of the HYSV infection in humans.

Description: We measured the effects of a diet in which d -β-hydroxybutyrate-( R )-1,3 butanediol monoester [ketone ester (KE)] replaced equicaloric amounts of carbohydrate on 8-wk-old male C57BL/6J mice. Diets contained equal amounts of fat, protein, and micronutrients. The KE group was fed ad libitum , whereas the control (Ctrl) mice were pair-fed to the KE group. Blood d -β-hydroxybutyrate levels in the KE group were 3-5 times those reported with high-fat ketogenic diets. Voluntary food intake was reduced dose dependently with the KE diet. Feeding the KE diet for up to 1 mo increased the number of mitochondria and doubled the electron transport chain proteins, uncoupling protein 1, and mitochondrial biogenesis-regulating proteins in the interscapular brown adipose tissue (IBAT). [ 18 F]-Fluorodeoxyglucose uptake in IBAT of the KE group was twice that in IBAT of the Ctrl group. Plasma leptin levels of the KE group were more than 2-fold those of the Ctrl group and were associated with increased sympathetic nervous system activity to IBAT. The KE group exhibited 14% greater resting energy expenditure, but the total energy expenditure measured over a 24-h period or body weights was not different. The quantitative insulin-sensitivity check index was 73% higher in the KE group. These results identify KE as a potential antiobesity supplement.—Srivastava, S., Kashiwaya, Y., King, M. T. Baxa, U., Tam, J., Niu, G., Chen, X., Clarke, K., Veech, R. L. Mitochondrial biogenesis and increased uncoupling protein 1 in brown adipose tissue of mice fed a ketone ester diet.

Description: Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations in PKD1 or PKD2 , and it affects over 10 million people worldwide. It is characterized by cyst formation in the kidney, liver and pancreas. Dosage changes in PKD1/PKD2 are important in ADPKD pathogenesis; therefore, their expression and function has to be strictly regulated. However, how they are regulated remain poorly understood. Recent studies have linked PKD2 regulation to endoplasmic reticulum (ER) stress that is implicated in neuronal, cardiac, and renal diseases. One major ER stress downstream is phosphorylation of eukaryotic initiation factor eIF2α by kinase PERK, which attenuates global protein translation and enhances translation of selected proteins. Here, we showed in several mammalian cell lines that PKD2 protein expression is up-regulated by different stresses that all increase phosphorylated eIF2α (P-eIF2α). Increasing P-eIF2α by overexpression or inhibiting the phosphatase activity resulted in increased PKD2. PCR and polysome-binding assays showed that ER stress does not affect the PKD2 mRNA level but increase its binding with ribosomes, indicating that P-eIF2α translationally up-regulates PKD2. By mutation analysis, we found that the upstream open reading frame (uORF) in the 5'-untranslated region of PKD2 mRNA represses PKD2 translation. Thus, ER stress and P-eIF2α translationally up-regulates PKD2 through bypassing the inhibitory uORF.—Yang, J., Zheng, W., Wang, Q., Lara, C., Hussein, S., and Chen, X.-Z. Translational up-regulation of polycystic kidney disease protein PKD2 by endoplasmic reticulum stress.