L.H. Pulz

Liver transcriptomic networks reveal main biological processes associated with feed efficiency in beef cattle

BackgroundThe selection of beef cattle for feed efficiency (FE) traits is very important not only for productive and economic efficiency but also for reduced environmental impact of livestock. Considering that FE is multifactorial and expensive to measure, the aim of this study was to identify biological functions and regulatory genes associated with this phenotype.ResultsEight genes were differentially expressed between high and low feed efficient animals (HFE and LFE, respectively). Co-expression analyses identified 34 gene modules of which 4 were strongly associated with FE traits. They were mainly enriched for inflammatory response or inflammation-related terms. We also identified 463 differentially co-expressed genes which were functionally enriched for immune response and lipid metabolism. A total of 8 key regulators of gene expression profiles affecting FE were found. The LFE animals had higher feed intake and increased subcutaneous and visceral fat deposition. In addition, LFE animals showed higher levels of serum cholesterol and liver injury biomarker GGT. Histopathology of the liver showed higher percentage of periportal inflammation with mononuclear infiltrate.ConclusionLiver transcriptomic network analysis coupled with other results demonstrated that LFE animals present altered lipid metabolism and increased hepatic periportal lesions associated with an inflammatory response composed mainly by mononuclear cells. We are now focusing to identify the causes of increased liver lesions in LFE animals.

Increased expression of tissue inhibitor of metalloproteinase-1 correlates with improved outcome in canine cutaneous mast cell tumours.

Canine mast cell tumour (MCT) is a biologically heterogeneous disease. The extracellular matrix degradation promoted by matrix metalloproteinases (MMPs) has been studied in an attempt to elucidate the mechanisms involved in the biological behaviour of tumours. The aim of this study was to characterize the expression of MMP-2 and -9 and tissue inhibitors of metalloproteinase (TIMP)-1 and -2 in canine cutaneous MCTs and to evaluate their prognostic values. Immunohistochemical staining for MMP-2, MMP-9, TIMP-2 and TIMP-1 was performed in 46 canine cases of MCTs. TIMP-1 expression showed an independent prognostic value for post-surgical survival and disease-related mortality. Dogs with MCTs showing less than 22.9% mast cell TIMP-1 positivity were more prone to die because of the disease and had a shorter post-surgical survival. This article suggests the involvement of TIMP-1 in MCT progression, by contributing to a good outcome in patients with MCTs.

Apoptotic intrinsic pathway proteins predict survival in canine cutaneous mast cell tumours: BARRAet al.

Mast cell tumours (MCTs) are the most frequent canine round cell neoplasms and show variable biological behaviours with high metastatic and recurrence rates. The disease is treated surgically and wide margins are recommended. Adjuvant chemotherapy and radiotherapy used in this disease cause DNA damage in neoplastic cells, which is aimed to induce apoptotic cell death. Resisting cell death is a hallmark of cancer, which contributes to the development and progression of tumours. The aim of this study was to investigate the expression of the proteins involved in the apoptotic intrinsic pathway and to evaluate their potential use as prognostic markers for canine cutaneous MCTs. Immunohistochemistry for BAX, BCL2, APAF1, Caspase-9, and Caspase-3 was performed in 50 canine cases of MCTs. High BAX expression was associated with higher mortality rate and shorter survival. BCL2 and APAF1 expressions offered additional prognostic information to the histopathological grading systems. The present results indicate that variations in the expression of apoptotic proteins are related to malignancy of cutaneous MCTs in dogs.

Immunohistochemical expression of Galectin-3 in canine tumors

Galectin-3 (Gal-3) is a protein expressed by both normal and neoplastic cells. It participates in several biological processes such as cell proliferation, cell adhesion, apoptosis, tissue remodeling, and angiogenesis. Although it is known to serve as a valuable prognostic marker in several types of human cancer, there are few reports about its applicability as a marker in the veterinary oncology literature. The aim of the present study was to characterize Gal-3 expression in different types of canine tumors. Fifty-three tissue samples from 22 histologically different types of canine tumors were immunohistochemically evaluated for Gal-3 expression. Variations in the percentage of Gal-3-positive cells, localization of Gal-3 protein, and percentage of Gal-3-positive fibroblasts were observed. These preliminary results showed variable expression of Gal-3 among canine tumors. Further studies are needed in order to investigate the potential of this protein as a prognostic marker and a therapeutic target.

Microvessel density is as a prognostic factor in canine cutaneous mast cell tumors

Background Mast cell tumors represent almost 25% of canine skin neoplasms. These tumors are classified in three grades of differentiation, based on histological features. However, this grading system is a method based on subjective parameters, which generate intra- and interobserver variations. The microcirculation is an important feature to the primary tumor expansion, dissemination and metastasis, and there are essential evidences that increasing microvessel density is associated with short survival disease-free intervals. The purpose of the present study was to verify the prognostic value of the intratumoral microvessel density (IMVD) in a set of canine cutaneous mast cell tumors. Materials and methods Twenty-nine canine cutaneous mast cell tumors were subjected to immunohistochemical analysis using a rabbit polyclonal antibody anti-human von Willebrand Factor. Subsequently, the IMVD was determined by the average number of vessels in 5 low-power fields.