Pregnane X receptor activation remodels glucose metabolism to promote NAFLD development in obese mice

OBJECTIVE

Both obesity and exposure to chemicals may induce non-alcoholic fatty liver disease (NAFLD). Pregnane X Receptor (PXR) is a central target of metabolism disrupting chemicals and disturbs hepatic glucose and lipid metabolism. We hypothesized that the metabolic consequences of PXR activation may be modified by existing obesity and associated metabolic dysfunction.

METHODS

Wildtype and PXR knockout male mice were fed high-fat diet to induce obesity and metabolic dysfunction. PXR was activated with pregnenolone-16α-carbonitrile. Glucose metabolism, hepatosteatosis, insulin signaling, glucose uptake, liver glycogen, plasma and liver metabolomics, and liver, white adipose tissue, and muscle transcriptomics were investigated.

RESULTS

PXR activation aggravated obesity-induced liver steatosis by promoting lipogenesis and inhibiting fatty acid disposal. Accordingly, hepatic insulin sensitivity was impaired and circulating alanine aminotransferase level increased. Lipid synthesis was facilitated by increased liver glucose uptake and utilization of glycogen reserves resulting in dissociation of hepatosteatosis and hepatic insulin resistance from the systemic glucose tolerance and insulin sensitivity. Furthermore, glucagon-induced hepatic glucose production was impaired. PXR deficiency did not protect from the metabolic manifestations of obesity, but the liver transcriptomics and metabolomics profiling suggest diminished activation of inflammation and less prominent changes in the overall metabolite profile.

CONCLUSIONS

Obesity and PXR activation by chemical exposure have a synergistic effect on NAFLD development. To support liver fat accumulation the PXR activation reorganizes glucose metabolism that seemingly improves systemic glucose metabolism. This implies that obese individuals, already predisposed to metabolic diseases, may be more susceptible to harmful metabolic effects of PXR-activating drugs and environmental chemicals.

Optimized detection and segmentation of nuclei in gastric cancer images using stain normalization and blurred artifact removal

Histological analysis with microscopy is the gold standard to diagnose and stage cancer, where slides or whole slide images are analyzed for cell morphological and spatial features by pathologists. The nuclei of cancerous cells are characterized by nonuniform chromatin distribution, irregular shapes, and varying size. As nucleus area and shape alone carry prognostic value, detection and segmentation of nuclei are among the most important steps in disease grading. However, evaluation of nuclei is a laborious, time-consuming, and subjective process with large variation among pathologists. Recent advances in digital pathology have allowed significant applications in nuclei detection, segmentation, and classification, but automated image analysis is greatly affected by staining factors, scanner variability, and imaging artifacts, requiring robust image preprocessing, normalization, and segmentation methods for clinically satisfactory results. In this paper, we aimed to evaluate and compare the digital image analysis techniques used in clinical pathology and research in the setting of gastric cancer. A literature review was conducted to evaluate potential methods of improving nuclei detection. Digitized images of 35 patients from a retrospective cohort of gastric adenocarcinoma at Oulu University Hospital in 1987-2016 were annotated for nuclei (n = 9085) by expert pathologists and 14 images of different cancer types from public TCGA dataset with annotated nuclei (n = 7000) were used as a comparison to evaluate applicability in other cancer types. The detection and segmentation accuracy with the selected color normalization and stain separation techniques were compared between the methods. The extracted information can be supplemented by patient's medical data and fed to the existing statistical clinical tools or subjected to subsequent AI-assisted classification and prediction models. The performance of each method is evaluated by several metrics against the annotations done by expert pathologists. The F1-measure of 0.854 ± 0.068 is achieved with color normalization for the gastric cancer dataset, and 0.907 ± 0.044 with color deconvolution for the public dataset, showing comparable results to the earlier state-of-the-art works. The developed techniques serve as a basis for further research on application and interpretability of AI-assisted tools for gastric cancer diagnosis.

Menaquinone 4 increases plasma lipid levels in hypercholesterolemic mice

In calcific aortic valve disease (CAVD) progressive valvular calcification causes aortic valve dysfunction. CAVD has several risk factors such as age and dyslipidemia. Vitamin K was shown to inhibit vascular calcification in mice and valvular calcification in patients with CAVD. We studied the effect of menaquinone 4 (MK4/vitamin K2) on valvular calcification in the hypercholesterolemic mouse model of CAVD. LDLr^−/−ApoB^100/100 male mice were fed with a Western diet for 5 months, with (n = 10) or without (n = 10) added 0.2 mg/g MK4. Body weight gain was followed weekly. Morphology of aortic valves and liver was assessed with immunohistochemistry. Plasma cholesterol levels and cytokines from hepatic tissue were assessed in the end of the study. Hepatic gene expression of lipid metabolism regulating genes were assessed after 18 h diet. MK4 exacerbated the lipoprotein lipid profile without affecting aortic valve morphology in hypercholesterolemic LDLr^−/− ApoB^100/100 mice. The MK4-containing WD diet increased plasma levels of LDL and triglycerides, hepatic steatosis, and mRNA expression of genes required for triglyceride and cholesterol synthesis. MK4 diminished levels of several cytokines and chemokines in liver, including IL-6, TNFα and MCP1, as measured by hepatic cytokine array. Consequently, MK4 may exert non-beneficial effects on circulating lipid levels, especially in hypercholesterolemic individuals.

Pediatric primary synovial chondromatosis of the shoulder, biceps tendon sheath and subcoracoid bursa

A child with shoulder pain and great palpable mass without any injury history is an emergent case until the diagnosis is confirmed. We report the clinical findings, imaging features, surgery and histological analyses of primary synovial chondromatosis in glenohumeral joint, biceps tendon sheath and subcoracoid bursa in a child, aged 14. Primary synovial chondromatosis is characterised by multiple calcified nodules in joints, tendons or bursa areas. The condition is more usual in large joints, in particular in lower extremities. It may be symptomless until the volume of chondromatosis has increased to such an extent that it results in pain, locking symptom or palpable mass. The treatment is removal of the loose bodies and potentially synovectomy, in means of open or arthroscope-assisted surgery. Postoperative follow-up is recommended due to the risk of recidivism and potential malignant transformation. The disease is more common in older patients and there are only isolated cases in pediatric population.

Adoption of diagnostic digital pathology in Finland

Digital pathology (DP) means digitizing histological glass slides for the assessment on a computer screen. In clinical diagnostics, DP is expected to reduce costs due to improved pathologist productivity with the aid of image analysis, workload distribution, and more accurate subspecialty-based diagnoses. The digital workflow also provides many advantages to research and education. However, the adoption of DP into clinical diagnostics has been slow. In this study, the current state and attitudes of the adoption of DP were explored with a questionnaire sent to the persons in charge of digitalization in all public pathology laboratories in Finland. Most of the respondents (75.0%) considered that there is a sufficient amount of validation studies about the safety of DP. The benefits of DP were seen in e.g. tumor boards (64.3%), logistics (64.3%), diagnostic quality (50.0%), and consultations (64.3%). All but one (92.9%) expected the level of digitalization to reach 100% in the following 12 years. The price of digitalization, specifically the cost of storage, was considered to be the most important barrier to a large-scale adoption of DP. The results suggest that there is a need for a substantial governmental financing: the virtual slide images could be stored in a central national image archive (e.g. Kvarkki) after diagnostics, leading to a remarkably reduced cost of local storage and an accelerated large-scale adoption of DP in the Finnish pathology laboratories. This would lead to improved diagnostic efficacy and quality by enabling better workload management locally and nationally. A central DP repository could serve as an invaluable database for e.g. biobank research

Characterizing valve dynamics in mice by high-resolution cine-MRI

AIMS

In calcific aortic valve disease (CAVD), progressive valvular sclerosis and calcification cause narrowing of the orifice and an impairment of the valve's function. We applied high-resolution cine-MRI to perform quantitative analysis of the dynamics of the aortic valve in a mice model of CAVD.

METHODS AND RESULTS

LDLr^-/- ApoB^100/100 mice were fed a Western diet (WD) or a standard diet (control) for 22 weeks. The mice were imaged in a 7 T horizontal MRI scanner, and aortic valve dynamics was examined by imaging the cross-section of the aorta at valve level using cine sequences. From these images, the area of the aortic valve orifice was determined during the heart cycle. MRI results were compared with echocardiographic and histopathologic results. The data revealed evidence of clear aortic valve dysfunction in WD mice as compared with control mice (interaction P < 0.001). MRI showed narrowing (14%, P < 0.05) of the orifice area, and this was also seen in histology (34%, P < 0.05), indicating more severe aortic stenosis after WD than in controls. Additionally, MRI revealed a reduction in the ejection fraction (EF) (-11%, P < 0.01), a result confirmed with echocardiography (-27%, P < 0.001) in mice fed with WD. EF detected by MRI and echocardiography also correlated strongly with the degree of stenosis assessed by histology.

CONCLUSIONS

Cine-MRI can be used for quantitative analysis of the aortic valve orifice over the cardiac cycle in mice. MRI showed the cusps clearly, and we were able to detect aortic valve dysfunction over time through the cardiac cycle.

Nuclear factor E2-related factor 2 deficiency impairs atherosclerotic lesion development but promotes features of plaque instability in hypercholesterolaemic mice

Aims

Oxidative stress and inflammation play an important role in the progression of atherosclerosis. Transcription factor NF-E2-related factor 2 (Nrf2) has antioxidant and anti-inflammatory effects in the vessel wall, but paradoxically, global loss of Nrf2 in apoE deficient mice alleviates atherosclerosis. In this study, we investigated the effect of global Nrf2 deficiency on early and advanced atherogenesis in alternative models of atherosclerosis, LDL receptor deficient mice (LDLR−/−), and LDLR−/− mice expressing apoB-100 only (LDLR−/− ApoB100/100) having a humanized lipoprotein profile.

Methods and results

LDLR−/− mice were fed a high-fat diet (HFD) for 6 or 12 weeks and LDLR−/−ApoB100/100 mice a regular chow diet for 6 or 12 months. Nrf2 deficiency significantly reduced early and more advanced atherosclerosis assessed by lesion size and coverage in the aorta in both models. Nrf2 deficiency in LDLR−/− mice reduced total plasma cholesterol after 6 weeks of HFD and triglycerides in LDLR−/−ApoB100/100 mice on a chow diet. Nrf2 deficiency aggravated aortic plaque maturation in aged LDLR−/−ApoB100/100 mice as it increased plaque calcification. Moreover, ∼36% of Nrf2−/−LDLR−/−ApoB100/100 females developed spontaneous myocardial infarction (MI) or sudden death at 5 to 12 months of age. Interestingly, Nrf2 deficiency increased plaque instability index, enhanced plaque inflammation and calcification, and reduced fibrous cap thickness in brachiocephalic arteries of LDLR−/−ApoB100/100 female mice at age of 12 months.

Conclusions

Absence of Nrf2 reduced atherosclerotic lesion size in both atherosclerosis models, likely via systemic effects on lipid metabolism. However, Nrf2 deficiency in aged LDLR−/−ApoB100/100 mice led to an enhanced atherosclerotic plaque instability likely via increased plaque inflammation and oxidative stress, which possibly predisposed to MI and sudden death.

Optimized JPEG 2000 Compression for Efficient Storage of Histopathological Whole-Slide Images

Background:

Whole slide images (WSIs, digitized histopathology glass slides) are large data files whose long-term storage remains a significant cost for pathology departments. Currently used WSI formats are based on lossy image compression alogrithms, either using JPEG or its more efficient successor JPEG 2000. While the advantages of the JPEG 2000 algorithm (JP2) are commonly recognized, its compression parameters have not been fully optimized for pathology WSIs.

Methods:

We defined an optimized parametrization for JPEG 2000 image compression, designated JP2-WSI, to be used specifically with histopathological WSIs. Our parametrization is based on allowing a very high degree of compression on the background part of the WSI while using a conventional amount of compression on the tissue-containing part of the image, resulting in high overall compression ratios.

Results:

When comparing the compression power of JP2-WSI to the commonly used fixed 35:1 compression ratio JPEG 2000 and the default image formats of proprietary Aperio, Hamamatsu, and 3DHISTECH scanners, JP2-WSI produced the smallest file sizes and highest overall compression ratios for all 17 slides tested. The image quality, as judged by visual inspection and peak signal-to-noise ratio (PSNR) measurements, was equal to or better than the compared image formats. The average file size by JP2-WSI amounted to 15, 9, and 16 percent, respectively, of the file sizes of the three commercial scanner vendors' proprietary file formats (3DHISTECH MRXS, Aperio SVS, and Hamamatsu NDPI). In comparison to the commonly used 35:1 compressed JPEG 2000, JP2-WSI was three times more efficient.

Conclusions:

JP2-WSI allows very efficient and cost-effective data compression for whole slide images without loss of image information required for histopathological diagnosis.

Activation of nuclear receptor PXR impairs glucose tolerance and dysregulates GLUT2 expression and subcellular localization in liver

Pregnane X receptor (PXR) is a nuclear receptor that senses chemical environment and is activated by numerous clinically used drugs and environmental contaminants. Previous studies have indicated that several drugs known to activate PXR appear to induce glucose intolerance. We now aimed to reveal the role of PXR in drug-induced glucose intolerance and characterize the mechanisms involved. We used PXR knockout mice model to investigate the significance of this nuclear receptor in the regulation of glucose tolerance. PXR ligand pregnenolone-16ɑ-carbonitrile (PCN) impaired glucose tolerance in the wildtype mice but not in the PXR knockout mice. Furthermore, DNA microarray and bioinformatics analysis of differentially expressed genes and glucose metabolism relevant pathways in PCN treated primary hepatocytes indicated that PXR regulates genes involved in glucose uptake. PCN decreased the expression of glucose transporter 2 (GLUT2) in mouse liver and in the wildtype mouse hepatocytes but not in the PXR knockout cells. Data mining of published chromatin immunoprecipitation-sequencing results indicate that Glut2 gene is a direct PXR target. Furthermore, PCN induced internalization of GLUT2 protein from the plasma membrane to the cytosol in the liver in vivo and repressed glucose uptake in the primary hepatocytes. Our results indicate that the activation of PXR impairs glucose tolerance and thus PXR represents a novel diabetogenic pathway. PXR activation dysregulates GLUT2 function by two different mechanisms. These findings may partly explain the diabetogenic effects of medications and environmental contaminants.

Mitogen-activated protein kinase p38 target regenerating islet-derived 3γ expression is upregulated in cardiac inflammatory response in the rat heart

Regenerating islet‐derived 3γ (Reg3γ) is a multifunctional protein, associated with various tissue injuries and inflammatory states. Since chronic inflammation is characteristics also for heart failure, the aim of this study was to characterize Reg3γ expression in cardiac inflammatory conditions. Reg3γ expression was studied in experimental rat models of myocardial infarction (MI) and pressure overload in vivo. For cell culture studies neonatal rat cardiac myocytes (NRCMs) were used. In addition, adenovirus‐mediated gene transfer of upstream mitogen‐activated protein kinase (MAPK) kinase 3b and p38α MAPK in vivo and in vitro was performed. Reg3γ mRNA (12.8‐fold, P < 0.01) and protein (5.8‐fold, P < 0.001) levels were upregulated during the postinfarction remodeling at day 1 after MI, and angiotensin II (Ang II) markedly increased Reg3γ mRNA levels from 6 h to 2 weeks. Immunohistochemistry revealed that the Ang II‐induced expression of Reg3γ was localized into the cardiac fibroblasts and myofibroblasts of the proliferating connective tissue in the heart. Stretching and treatments with endothelin‐1, lipopolysaccharide (LPS), and fibroblast growth factor‐1 increased Reg3γ mRNA levels in NRCMs. SB203580, a selective p38 MAPK inhibitor, markedly attenuated LPS and mechanical stretch‐induced upregulation of Reg3γ gene expression. Moreover, combined overexpression of MKK3bE and WT p38α increased Reg3γ gene expression in cultured cardiomyocytes in vitro and in the rat heart in vivo. Our study shows that cardiac stress activates Reg3γ expression and p38 MAPK is an upstream regulator of Reg3γ gene expression in heart. Altogether our data suggest Reg3γ is associated with cardiac inflammatory signaling.

Distal Inside-Out Epineural Sliding Technique to Repair Segmental Nerve Defects

Background: The repair of a segmental peripheral nerve injury is a clinical challenge. Several studies have been performed to determine superior methods for overcoming nerve gaps. The purpose of this study was to investigate if the inside-out slided epineurium of the distal segment of an injured nerve can serve as a conduit to bridge a short nerve defect (10 mm). Methods: Nineteen sciatic nerves in Sprague-Dawley rats were transected, and a 10-mm gap was left between the ends. A section of distal epineurium was pulled inside out to bridge the gap. Walking track analysis was performed, and the sciatic function index (SFI) was calculated. Wet muscle mass and withdrawal reflex were measured. The density of axon fibers at different levels of repaired nerves was determined, and histological analysis was performed at 16 weeks. Results: The mean SFI improved from -81.0 at 4 weeks to 36.3 at 16 weeks. The axon densities showed regeneration through the epineural tube, and 5 of the rats demonstrated a withdrawal reflex. The weight of the tibialis anterior muscle of the injured limb at 16 weeks was 59% that of the uninjured side. Conclusions: The distal epineural sheath tube provided a size-matched conduit between the nerve stumps, with no histological donor-site morbidity. Histologically, regeneration occurred through the epineural tube without neuroma formation, and functional recovery was comparable to that of previous studies of nerve repair techniques. Technique may be an addition to the armamentarium of tools used to treat segmental nerve defects.

TSC-22 up-regulates collagen 3a1 gene expression in the rat heart

BACKGROUND

The transforming growth factor (TGF)-β is one of the key mediators in cardiac remodelling occurring after myocardial infarction (MI) and in hypertensive heart disease. The TGF-β-stimulated clone 22 (TSC-22) is a leucine zipper protein expressed in many tissues and possessing various transcription-modulating activities. However, its function in the heart remains unknown.

METHODS

The aim of the present study was to characterize cardiac TSC-22 expression in vivo in cardiac remodelling and in myocytes in vitro. In addition, we used TSC-22 gene transfer in order to examine the effects of TSC-22 on cardiac gene expression and function.

RESULTS

We found that TSC-22 is rapidly up-regulated by multiple hypertrophic stimuli, and in post-MI remodelling both TSC-22 mRNA and protein levels were up-regulated (4.1-fold, P <0.001 and 3.0-fold, P <0.05, respectively) already on day 1. We observed that both losartan and metoprolol treatments reduced left ventricular TSC-22 gene expression. Finally, TSC-22 overexpression by local intramyocardial adenovirus-mediated gene delivery showed that TSC-22 appears to have a role in regulating collagen type IIIα1 gene expression in the heart.

CONCLUSIONS

These results demonstrate that TSC-22 expression is induced in response to cardiac overload. Moreover, our data suggests that, by regulating collagen expression in the heart in vivo, TSC-22 could be a potential target for fibrosis-preventing therapies.

The Early-Onset Myocardial Infarction Associated PHACTR1 Gene Regulates Skeletal and Cardiac Alpha-Actin Gene Expression

The phosphatase and actin regulator 1 (PHACTR1) locus is a very commonly identified hit in genome-wide association studies investigating coronary artery disease and myocardial infarction (MI). However, the function of PHACTR1 in the heart is still unknown. We characterized the mechanisms regulating Phactr1 expression in the heart, used adenoviral gene delivery to investigate the effects of Phactr1 on cardiac function, and analyzed the relationship between MI associated PHACTR1 allele and cardiac function in human subjects. Phactr1 mRNA and protein levels were markedly reduced (60%, P<0.01 and 90%, P<0.001, respectively) at 1 day after MI in rats. When the direct myocardial effects of Phactr1 were studied, the skeletal α-actin to cardiac α-actin isoform ratio was significantly higher (1.5-fold, P<0.05) at 3 days but 40% lower (P<0.05) at 2 weeks after adenovirus-mediated Phactr1 gene delivery into the anterior wall of the left ventricle. Similarly, the skeletal α-actin to cardiac α-actin ratio was lower at 2 weeks in infarcted hearts overexpressing Phactr1. In cultured neonatal cardiac myocytes, adenovirus-mediated Phactr1 overexpression for 48 hours markedly increased the skeletal α-actin to cardiac α-actin ratio, this being associated with an enhanced DNA binding activity of serum response factor. Phactr1 overexpression exerted no major effects on the expression of other cardiac genes or LV structure and function in normal and infarcted hearts during 2 weeks’ follow-up period. In human subjects, MI associated PHACTR1 allele was not associated significantly with cardiac function (n = 1550). Phactr1 seems to regulate the skeletal to cardiac α-actin isoform ratio.

WDR12, a Member of Nucleolar PeBoW-Complex, Is Up-Regulated in Failing Hearts and Causes Deterioration of Cardiac Function

Aims

In a recent genome-wide association study, WD-repeat domain 12 (WDR12) was associated with early-onset myocardial infarction (MI). However, the function of WDR12 in the heart is unknown.

Methods and Results

We characterized cardiac expression of WDR12, used adenovirus-mediated WDR12 gene delivery to examine effects of WDR12 on left ventricular (LV) remodeling, and analyzed relationship between MI associated WDR12 allele and cardiac function in human subjects. LV WDR12 protein levels were increased in patients with dilated cardiomyopathy and rats post-infarction. In normal adult rat hearts, WDR12 gene delivery into the anterior wall of the LV decreased interventricular septum diastolic and systolic thickness and increased the diastolic and systolic diameters of the LV. Moreover, LV ejection fraction (9.1%, P<0.05) and fractional shortening (12.2%, P<0.05) were declined. The adverse effects of WDR12 gene delivery on cardiac function were associated with decreased cellular proliferation, activation of p38 mitogen–activated protein kinase (MAPK)/heat shock protein (HSP) 27 pathway, and increased protein levels of Block of proliferation 1 (BOP1), essential for ribosome biogenesis. Post-infarction WDR12 gene delivery decreased E/A ratio (32%, P<0.05) suggesting worsening of diastolic function. In human subjects, MI associated WDR12 allele was associated significantly with diastolic dysfunction and left atrial size.

Conclusions

WDR12 triggers distinct deterioration of cardiac function in adult rat heart and the MI associated WDR12 variant is associated with diastolic dysfunction in human subjects.

[Clinical pathology on the verge of virtual microscopy]

For more than 100 years, examinations of pathology specimens have relied on the use of the light microscope. The technological progress of the last few years is enabling the digitizing of histologic specimen slides and application of the virtual microscope in diagnostics. Virtual microscopy will facilitate consultation possibilities, and digital image analysis serves to enhance the level of diagnostics. Organizing and monitoring clinicopathological meetings will become easier. Digital archive of histologic specimens and the virtual microscopy network are expected to benefit training and research as well, particularly what applies to the Finnish biobank network which is currently being established.

MicroRNA-125b and chemokine CCL4 expression are associated with calcific aortic valve disease

Calcific aortic valve disease (CAVD) is a progressive pathological condition with no effective pharmacological therapy. To identify novel molecular pathways as potential targets for pharmacotherapy, we studied microRNA (miRNA) profiles of heavily stenotic aortic valves (AS). One of the most upregulated miRNAs in AS valves compared to control valves was miR-125b (1.4-fold; P < 0.05). To identify CAVD-related changes in gene expression, DNA microarray analysis was performed, including an intermediate fibro(sclero)tic stage of the disease. This revealed changes especially in genes related to inflammation and immune response, including chemokine (C-C motif) ligand 3 (CCL3) and 4 (CCL4). CCL3 mRNA level was increased 3.9-fold (P < 0.05) when AS valves were compared to control valves, and a 2.5-fold increase (P < 0.05) in CCL4 gene expression was observed when fibro(sclero)tic valves were compared to control valves. Both CCL3 and CCL4 localized to macrophages by immunofluorescence. To identify chemokine-miRNA target pairs, data from miRNA target prediction databases were combined with valvular miRNA and mRNA expression profiles. MiR-125b was computationally predicted to target CCL4, as confirmed experimentally in cultured human THP-1 macrophages. Collectively, miR-125b and CCL4 appear to be involved in the progression of CAVD and may offer novel therapeutic and diagnostic strategies related to this disease.

Stage-dependent alterations of the serum cytokine pattern in colorectal carcinoma

Background:

Inflammation contributes to the pathogenesis of colorectal cancer (CRC), and cytokine levels are altered during colorectal carcinogenesis.

Methods:

The serum levels of 13 cytokines and their relation to clinical and pathological parameters, and systemic inflammatory response (mGPS, CRP and neutrophil–lymphocyte ratio), were analysed from a prospective series of 148 CRC patients and 86 healthy age- and sex-matched controls.

Results:

CRC patients had higher serum platelet-derived growth factor, interleukin (IL)-6, IL-7, and IL-8 levels and lower monocyte chemotactic protein-1 (MCP-1) levels than the controls. A logistic regression model for discriminating the patients from the controls – including the five most predictive cytokines (high IL-8, high IL-6, low MCP-1, low IL-1ra, and low IP-10) – yielded an area under curve value of 0.890 in receiver operating characteristics analysis. Serum cytokines showed distinct correlation with other markers of systemic inflammatory response, and advanced CRCs were associated with higher levels of IL-8, IL-1ra, and IL-6. A metastasised disease was accompanied by an orientation towards Th2 cytokine milieu.

Conclusion:

CRC is associated with extensive alterations in serum cytokine environment, highlighting the importance of studying relative cytokine level alterations. Serum cytokine profile shows promise in separating CRC patients from healthy controls but its clinical value is yet to be confirmed.

(Pro)renin receptor triggers distinct angiotensin II-independent extracellular matrix remodeling and deterioration of cardiac function

Background

Activation of the renin-angiotensin-system (RAS) plays a key pathophysiological role in heart failure in patients with hypertension and myocardial infarction. However, the function of (pro)renin receptor ((P)RR) is not yet solved. We determined here the direct functional and structural effects of (P)RR in the heart.

Methodology/Principal Findings

(P)RR was overexpressed by using adenovirus-mediated gene delivery in normal adult rat hearts up to 2 weeks. (P)RR gene delivery into the anterior wall of the left ventricle decreased ejection fraction (P<0.01), fractional shortening (P<0.01), and intraventricular septum diastolic and systolic thickness, associated with approximately 2–fold increase in left ventricular (P)RR protein levels at 2 weeks. To test whether the worsening of cardiac function and structure by (P)RR gene overexpression was mediated by angiotensin II (Ang II), we infused an AT₁ receptor blocker losartan via osmotic minipumps. Remarkably, cardiac function deteriorated in losartan-treated (P)RR overexpressing animals as well. Intramyocardial (P)RR gene delivery also resulted in Ang II-independent activation of extracellular-signal-regulated kinase1/2 phosphorylation and myocardial fibrosis, and the expression of transforming growth factor-β1 and connective tissue growth factor genes. In contrast, activation of heat shock protein 27 phosphorylation and apoptotic cell death by (P)RR gene delivery was Ang II-dependent. Finally, (P)RR overexpression significantly increased direct protein–protein interaction between (P)RR and promyelocytic zinc-finger protein.

Conclusions/Significance

These results indicate for the first time that (P)RR triggers distinct Ang II-independent myocardial fibrosis and deterioration of cardiac function in normal adult heart and identify (P)RR as a novel therapeutic target to optimize RAS blockade in failing hearts.

The hypermethylation of the O6-methylguanine-DNA methyltransferase gene promoter in gliomas--correlation with array comparative genome hybridization results and IDH1 mutation

The use of molecular markers in the diagnostics of gliomas aids histopathological diagnosis and allows their further classification into clinically significant subgroups. The aim of this study was to characterize the methylation pattern of the O(6) -methylguanine-DNA methyltransferase (MGMT) promoter, gene copy number aberrations, and isocitrate dehydrogenase I (IDH1) mutation in gliomas. We studied 51 gliomas (15 oligodendrogliomas, 18 oligoastrocytomas, 3 astrocytomas, and 15 glioblastomas) by pyrosequencing, array comparative genome hybridization (CGH), and immunohistochemistry. MGMT hypermethylation was observed in 100% of oligoastrocytomas, 93% of oligodendrogliomas, and 47% of glioblastomas. The most frequently altered chromosomal regions were deletions of 1p31.1/21.1-22.2 and 19q13.3qter in oligodendroglial tumors, and losses of 9p21.3, 10q25.3qter, and 10q26.13-26.2 in glioblastomas. Deletions on 9p and 10q, and gain of 7p were associated with the unmethylated MGMT phenotype, whereas deletion of 19q and oligodendroglial morphology was associated with MGMT hypermethylation. IDH1 mutation showed positive correlation with MGMT hypermethylation and loss of 1p/19q. Our results suggest that MGMT promoter methylation, analyzed by pyrosequencing, is a frequent event in oligodendroglial tumors, and it correlates with IDH1 mutation and 19q loss in gliomas. Pyrosequencing proved a good method for assessing the degree of MGMT methylation in formalin-fixed paraffin-embedded glioma samples. However, further studies are needed to confirm a clinically relevant cut-off point for MGMT methylation in gliomas.

Statin treatment and gene expression of anti-atherogenic factor C-type natriuretic peptide system in stenotic aortic valves

AIMS

Aortic valve calcification is an actively regulated process with endothelial dysfunction displaying hallmarks of atherosclerosis. C-type natriuretic peptide (CNP) system has been reported to have a role in the pathogenesis of vascular atherosclerosis and to be distinctly downregulated in aortic valve stenosis (AS). Here we studied gene expressions of CNP and is target receptor natriuretic peptide receptor type B (NPR-B) in human aortic valves. Furthermore, we compared gene expression of CNP system in patients with HMG-coenzyme-A reductase (statin) treatment to non-statin-treated patients in AS group.

METHODS AND RESULTS

With the study population of 108 patients, we characterized expression of CNP and NPR-B in human aortic valves and compared normal control valves (n = 12) with valves obtained from patients with aortic regurgitation (AR, n = 16), AR with fibrosis (AR+fibr., n = 19) and AS (n = 61). By reverse transcription-polymerase chain reaction (RT-PCR), CNP mRNA levels were 89% lower (p = 0.022) in stenotic valves, when compared to AR group. Moreover, the mRNA levels of NPR-B, the target receptor of CNP, were 62% lower (p < 0.001) in stenotic valves when compared to control group and 54% lower (p = 0.002) in stenotic valves, when compared to AR group. There was no statistical significant difference in CNP and NPR-B levels in AS group when the statin-treated patients were compared to untreated patients.

CONCLUSIONS

These results show for the first time that the gene expression of anti-atherogenic CNP system did not differ between statin-treated and non-statin-treated patients in AS. The research data supports the results of clinical trials with the same drug class.

Left ventricular periostin gene expression is associated with fibrogenesis in experimental renal insufficiency

BACKGROUND

Cardiovascular diseases are the most important cause of death in patients with impaired kidney function. Left ventricular hypertrophy (LVH), cardiac interstitial fibrosis and cardiovascular calcifications are characteristic of chronic renal insufficiency (CRI). Periostin is a fibrogenesis- and calcification-related matricellular protein re-expressed in adult tissues undergoing remodelling in response to pathological stimuli. The role of periostin in CRI-induced LVH is unknown.

METHODS

Rats were 5/6-nephrectomized (NX), and after 15 weeks of disease progression high-calcium, high-phosphate or paricalcitol treatment was given for 12 weeks. Cardiac tissue and blood samples were taken to study periostin gene expression and to determine factors contributing to its reactivation, respectively. Left ventricular (LV) periostin expression was also examined in response to angiotensin II or arginine(8)-vasopressin (AVP)-induced pressure overload and in spontaneously hypertensive rats.

RESULTS

CRI resulted in a 6.5-fold increase in LV periostin messenger RNA (mRNA) levels. Positive extracellular immunostaining for periostin was detected in areas of infiltrated inflammatory cells and fibrotic lesions. There was a significant correlation between LV periostin mRNA levels and plasma biomarkers of impaired kidney function, LVH, fibrogenesis-related proteins osteopontin and osteoactivin, and anti-calcific matrix Gla protein. Moreover, LV periostin gene expression in CRI correlated positively with systolic blood pressure (BP) and was activated rapidly in response to angiotensin II or AVP infusions.

CONCLUSIONS

Periostin is involved in fibrotic cardiac remodelling in CRI. The re-expression of periostin is localized to the fibrotic and inflammatory lesions and is most likely the consequence of elevated BP.

Apelin and its receptor APJ in human aortic valve stenosis

BACKGROUND AND AIM OF THE STUDY

Aortic valve stenosis (AS) is an actively regulated pathobiological process that shows some hallmarks of atherosclerosis. Apelin and its receptor, APJ, are highly expressed in the heart, and the proposed effects of the apelin-APJ system are opposite to those of the angiotensin II-AT1-receptor pathway. The role of the apelin-APJ signaling pathway in calcified aortic valve disease is unknown.

METHODS

The study involved the characterization and comparison of expression of apelin and APJ as well as angiotensin II receptors (AT1 and AT2) in the aortic valves of patients with normal valves (n = 6), aortic regurgitation (n = 9 AR), regurgitation and fibrosis/mild sclerosis (n = 14), and AS (n = 25).

RESULTS

By employing the reverse-transcriptase polymerase chain reaction (RT-PCR), the gene expression of apelin (3.63-fold, p = 0.001) and the APJ receptor (2.70-fold, p = 0.01) were shown to be significantly up-regulated in stenotic valves when compared to controls. In addition, APJ receptor mRNA levels were higher (2.9-fold, p = 0.010) in the AR + sclerosis group when compared to controls. Using immunohistochemistry, apelin was shown to be localized in stenotic aortic valves to the valvular endothelial layer of the aortic valve, to vascular endothelial cells in neovessels, and to fibroblasts and macrophages adjacent to vessels in the stromal area. AT2-receptor mRNA levels were 90% (p < 0.001) lower in stenotic valves. In contrast, the gene expression of AT1-receptors did not differ significantly among the groups.

CONCLUSION

Aortic valve stenosis is characterized by an up-regulation of the apelin-APJ signaling pathway, revealing a possible novel target for drug discovery in calcified aortic valve disease by suppressing chemotaxis, angiogenesis and osteoblast activity, all of which are well-documented phenomena in the disease process.