Lung inflammation after bleomycin treatment in mice: Selection of an accurate normalization strategy for gene expression analysis in an ex-vivo and in-vitro model

Pulmonary fibrosis (PF) is the most common and aggressive interstitial lung disease, characterized by a patchy development of fibrosis leading to progressive destruction of the normal lung architecture which is preceded by an inflammatory process. Gene expression studies are important to understand the development of PF but the accuracy and reproducibility of Real-Time PCR depend on appropriate normalization strategies. This study aimed to analyze the expression variability of eight commonly used reference genes during the initial inflammatory phase of bleomycin-induced PF in a mouse model and to verify whether the selected reference genes could be applied to an in-vitro model of BLM-treated primary murine lung fibroblasts. Wild-type C57BL/6 mice (n=40) were used. Real-Time PCR was carried out on lung tissue of mice either BLM (BLM-tm) or physiological solution-treated (PSS-tm), and in primary lung fibroblasts, isolated from healthy C57BL/6 mice. Histological analysis was performed to confirm the inflammation development. During inflammation, the most stable genes resulted: PPIA, HPRT-1 and SDHA for both models; the normalization strategy was tested analyzing mRNA expression of PTX-3 and TNF-α which resulted up-regulated both in ex-vivo and in-vitro with respect to PSS-tm/fibroblasts. Histological analysis supported the results. This study identified a new set of reference genes expressed both in the in-vitro and ex-vivo models. A higher expression of both markers in BLM-tm with respect to PSS-tm indicated that BLM might lead to increased PTX-3 local production by a co-regulation with TNF-α at lung level.

Quantitative micro-CT based coronary artery profiling using interactive local thresholding and cylindrical coordinates

BACKGROUND

Micro-CT is an established imaging technique for high-resolution non-destructive assessment of vascular samples, which is gaining growing interest for investigations of atherosclerotic arteries both in humans and in animal models. However, there is still a lack in the definition of micro-CT image metrics suitable for comprehensive evaluation and quantification of features of interest in the field of experimental atherosclerosis (ATS).

OBJECTIVE

A novel approach to micro-CT image processing for profiling of coronary ATS is described, providing comprehensive visualization and quantification of contrast agent-free 3D high-resolution reconstruction of full-length artery walls.

METHODS

Accelerated coronary ATS has been induced by high fat cholesterol-enriched diet in swine and left coronary artery (LCA) harvested en bloc for micro-CT scanning and histologic processing. A cylindrical coordinate system has been defined on the image space after curved multiplanar reformation of the coronary vessel for the comprehensive visualization of the main vessel features such as wall thickening and calcium content. A novel semi-automatic segmentation procedure based on 2D histograms has been implemented and the quantitative results validated by histology.

RESULTS

The potentiality of attenuation-based micro-CT at low kV to reliably separate arterial wall layers from adjacent tissue as well as identify wall and plaque contours and major tissue components has been validated by histology. Morphometric indexes from histological data corresponding to several micro-CT slices have been derived (double observer evaluation at different coronary ATS stages) and highly significant correlations (R2 > 0.90) evidenced. Semi-automatic morphometry has been validated by double observer manual morphometry of micro-CT slices and highly significant correlations were found (R2 > 0.92).

CONCLUSION

The micro-CT methodology described represents a handy and reliable tool for quantitative high resolution and contrast agent free full length coronary wall profiling, able to assist atherosclerotic vessels morphometry in a preclinical experimental model of coronary ATS and providing a link between in vivo imaging and histology.

Myocardial interleukin-6 in the setting of left ventricular mechanical assistance: relation with outcome and C-reactive protein

BACKGROUND

In left ventricular assist device (LVAD) recipients, plasma levels of interleukin (IL)-6 are associated with Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profiles, reflecting post-operative risk. However, it is not clear how the cardiac level of IL-6, detectable on the tissue samples at the time of implantation, can contribute to predict the post-operative outcome.

METHODS

In 40 LVAD recipients, blood and myocardial samples from LV-apex were collected at the time of implantation to assess plasma and cardiac IL-6 levels. Serum C-reactive protein (CRP) levels were considered as inflammatory variable routinely used in LVAD-based therapy.

RESULTS

Cardiac IL-6 levels did not correlate with either plasma IL-6 levels (R=0.296, p=0.063) and tissue IL-6 mRNA expression (R=-0.013, p=0.954). Contrary to what happened for the plasma IL-6 and CRP, no differences were observed in cardiac IL-6 levels with respect to INTERMACS profiles (p=0.090). Furthermore, cardiac IL-6 concentrations, unlike IL-6 and CRP circulating levels, were not correlated with the length of intensive care unit stay and hospitalization.

CONCLUSIONS

Cardiac IL-6 levels do not contribute to improve risk profile of LVAD recipients in relation to clinical inpatient post-implantation. Instead, plasma IL-6 and serum CRP concentrations are more effective in predicting the severity of the clinical course in the early phase of LVAD therapy.

Caspase-1 transcripts in failing human heart after mechanical unloading

BACKGROUND

Caspase (Casp)-1 has been indicated as a molecular target capable of preventing the progression of cardiovascular diseases, including heart failure (HF), due to its central role in promoting inflammation and cardiomyocyte loss. The aim of this study was to assess whether Left Ventricular Assist Device (LVAD) implantation modifies the inflammatory and apoptotic profile in the heart through the modulation of Casp-1 expression level.

METHODS

Cardiac tissue was collected from end-stage HF patients before LVAD implant (pre-LVAD group, n=22) and at LVAD removal (post-LVAD, n=6), and from stable HF patients on medical therapy without prior circulatory support (HTx, n=7) at heart transplantation, as control. The cardiac expression of Casp-1, of its inhibitors caspase recruitment domain (CARD) only protein (COP) and CARD family, member 18 (ICEBERG), was evaluated by real-time PCR in the three groups of patients.

RESULTS

Casp-1 was increased in the pre-LVAD group compared to HTx (p=0.006), while on the contrary the ICEBERG level was significantly decreased in pre-LVAD with respect to HTx patients (p<0.001); no difference in COP expression level was found.

CONCLUSIONS

This study describes a specific pattern of the Casp-1 system associated with inflammation and apoptosis markers in patients who require LVAD insertion. The inflammation could be the key process regulating, in a negative loop, Casp-1 signaling and its down-stream effects, apoptosis included.

Novel epigenetic target therapy for prostate cancer: a preclinical study

Epigenetic events are critical contributors to the pathogenesis of cancer, and targeting epigenetic mechanisms represents a novel strategy in anticancer therapy. Classic demethylating agents, such as 5-Aza-2′-deoxycytidine (Decitabine), hold the potential for reprograming somatic cancer cells demonstrating high therapeutic efficacy in haematological malignancies. On the other hand, epigenetic treatment of solid tumours often gives rise to undesired cytotoxic side effects. Appropriate delivery systems able to enrich Decitabine at the site of action and improve its bioavailability would reduce the incidence of toxicity on healthy tissues. In this work we provide preclinical evidences of a safe, versatile and efficient targeted epigenetic therapy to treat hormone sensitive (LNCap) and hormone refractory (DU145) prostate cancers. A novel Decitabine formulation, based on the use of engineered erythrocyte (Erythro-Magneto-Hemagglutinin Virosomes, EMHVs) drug delivery system (DDS) carrying this drug, has been refined. Inside the EMHVs, the drug was shielded from the environment and phosphorylated in its active form. The novel magnetic EMHV DDS, endowed with fusogenic protein, improved the stability of the carried drug and exhibited a high efficiency in confining its delivery at the site of action in vivo by applying an external static magnetic field. Here we show that Decitabine loaded into EMHVs induces a significant tumour mass reduction in prostate cancer xenograft models at a concentration, which is seven hundred times lower than the therapeutic dose, suggesting an improved pharmacokinetics/pharmacodynamics of drug. These results are relevant for and discussed in light of developing personalised autologous therapies and innovative clinical approach for the treatment of solid tumours.

Inflammation blood and tissue factors of plaque growth in an experimental model evidenced by a systems approach

Purpose: The multifactorial pathogenesis of coronary atherosclerotic lesion formation has been investigated in a swine model of high cholesterol diet induced atherogenesis and data processed by a systems approach.

Methods: Farm pigs were fed on standard or high cholesterol diet of 8 and 16 weeks duration. Plasma assessment of total cholesterol, HDL, LDL, and ELISA of some cytokines and ICAM-1 were performed on baseline and end-diet samples. Segments of the right coronary artery were incubated for 24 h in serum-free medium to collect secreted proteins and their expression analyzed by mass spectrometry. Data of plasma and tissue factors were processed by a statistical systems inference approach: both histologic parameters of coronary intimal thickness (IT) and of lesion area (LA) were chosen as dependent variables (coronary atherosclerotic burden).

Results: Relations among plasma adhesion molecules, cytokines, lipoproteins, tissue proteins and histology indexes were integrated in a model regression scheme. Bayesian model averaging (BMA) variable selection was chosen as a method to identify relevant factors associated to atherosclerotic burden: TNFα was identified as an associated plasma marker, oxLDL and HDL as relevant lipoproteins; macrophage function related antioxidant Catalase enzyme, lysosome associated Cathepsin D, S100-A10, and Transforming growth factor-beta-induced protein ig-h3 were identified and selected as associated to atherogenesis outcome.

Conclusions: The results of this systems approach are consistent with the hypothesis that, in high cholesterol diet-induced experimental atherogenesis, the interaction between plasma cytokines, lipoproteins and artery-specific proteins, influences lesion initiation and growth. In particular, some macrophage function related proteins are found significantly and positively associated to atherosclerotic burden, suggesting a novel molecular framework into the atherogenesis-inflammatory disorder.

Secreted proteins from carotid endarterectomy: an untargeted approach to disclose molecular clues of plaque progression

BACKGROUND

Atherosclerosis is the main cause of morbidity and mortality in Western countries and carotid plaque rupture is associated to acute events and responsible of 15-20% of all ischemic strokes. Several proteomics approaches have been up to now used to elucidate the molecular mechanisms involved in plaque formation as well as to identify markers of pathology severity for early diagnosis or target of therapy. The aim of this study was to characterize the plaque secretome. The advantage of this approach is that secretome mimics the in vivo condition and implies a reduced complexity compared to the whole tissue proteomics allowing the detection of under-represented potential biomarkers.

METHODS

Secretomes from carotid endarterectomy specimens of 14 patients were analyzed by a liquid chromatography approach coupled with label free mass spectrometry. Differential expression of proteins released from plaques and from their downstream distal side segments were evaluated in each specimen. Results were validated by Western blot analysis and ELISA assays. Histology and immunohistochemistry were performed to characterize plaques and to localise the molecular factors highlighted by proteomics.

RESULTS

A total of 463 proteins were identified and 31 proteins resulted differentially secreted from plaques and corresponding downstream segments. A clear-cut distinction in the distribution of cellular- and extracellular-derived proteins, evidently related to the higher cellularity of distal side segments, was observed along the longitudinal axis of carotid endarterectomy samples. The expressions of thrombospondin-1, vitamin D binding protein, and vinculin, as examples of extracellular and intracellular proteins, were immunohistologically compared between adjacent segments and validated by antibody assays. ELISA assays of plasma samples from 34 patients and 10 healthy volunteers confirmed a significantly higher concentration of thrombospondin-1 and vitamin D binding protein in atherosclerotic subjects.

CONCLUSIONS

Taking advantage of the optimized workflow, a detailed protein profile related to carotid plaque secretome has been produced which may assist and improve biomarker discovery of molecular factors in blood. Distinctive signatures of proteins secreted by adjacent segments of carotid plaques were evidenced and they may help discriminating markers of plaque complication from those of plaque growth.

Possible pathogenetic relationship between Fabry disease and renal cell carcinoma

The occurrence of renal cell carcinoma (RCC) in Fabry disease (FD) is a rare event. We report a deep ultrastructural study of RCC in a patient with a previous histological diagnosis of FD. In order to highlight analogies and differences between the two histological samples, we used the nephrectomy specimen as a 'repeat biopsy', making a dynamic analysis of the evolution of the disease-related kidney damage. Secondly, a comparative ultrastructural analysis between non-neoplastic tissue and cancer demonstrated for the first time the presence of zebra bodies in the tumor cells. Finally, a hypothetical speculation about the relationship between the lysosomal accumulation, the oxidative damage and the genesis of the tumor was performed. The link connected the accumulation of glycosphingolipid globotriaosylceramide, characteristic of FD, with the expression of CD74 and macrophage migration inhibitory factor that may play an important role in tumorigenesis regulated by the Von Hippel-Lindau/hypoxia-inducible factor 1α pathway.