Silicon as a Functional Meat Ingredient Improves Jejunal and Hepatic Cholesterol Homeostasis in a Late-Stage Type 2 Diabetes Mellitus Rat Model.

Silicon included in a restructured meat (RM) matrix (Si-RM) as a functional ingredient has been demonstrated to be a potential bioactive antidiabetic compound. However, the jejunal and hepatic molecular mechanisms by which Si-RM exerts its cholesterol-lowering effects remain unclear. Male Wistar rats fed an RM included in a high-saturated-fat high-cholesterol diet (HSFHCD) combined with a low dose of streptozotocin plus nicotinamide injection were used as late-stage type 2 diabetes mellitus (T2DM) model. Si-RM was included into the HSFHCD as a functional food. An early-stage TD2M group fed a high-saturated-fat diet (HSFD) was taken as reference. Si-RM inhibited the hepatic and intestinal microsomal triglyceride transfer protein (MTP) reducing the apoB-containing lipoprotein assembly and cholesterol absorption. Upregulation of liver X receptor (LXRα/ß) by Si-RM turned in a higher low-density lipoprotein receptor (LDLr) and ATP-binding cassette transporters (ABCG5/8, ABCA1) promoting jejunal cholesterol efflux and transintestinal cholesterol excretion (TICE), and facilitating partially reverse cholesterol transport (RCT). Si-RM decreased the jejunal absorptive area and improved mucosal barrier integrity. Consequently, plasma triglycerides and cholesterol levels decreased, as well as the formation of atherogenic lipoprotein particles. Si-RM mitigated the dyslipidemia associated with late-stage T2DM by Improving cholesterol homeostasis. Silicon could be used as an effective nutritional approach in diabetic dyslipidemia management.

Synovial myxosarcoma in the scapulohumeral joint of a dog: a case report.

A 12-year-old, 3 kg spayed female mixed-breed dog was evaluated to assess a 1-year history of intermittent right forelimb lameness that did not have adequate response to nonsteroidal anti-inflammatory drugs. The radiographic study performed under sedation showed multifocal radiolucent areas affecting both the right humerus and scapula with focal soft tissue swelling; a CT scan confirmed the existence of an aggressive and invasive soft tissue mass affecting the scapulohumeral joint. Fine needle aspiration results suggested a low-grade synovial sarcoma and therefore a scapulectomy was performed. The biopsy showed spindle to stellated cells immersed in a basophilic and mucinous (myxoid) matrix with mild to moderate anisocytosis, moderate anisokaryosis, some binucleated cells and sporadic multinucleated cells. These findings are consistent with low-grade synovial myxosarcoma, a not well described synovial neoplasm that can mimic other commonly seen joint tumors or even septic arthritis on radiographs. The purpose of this case report is to describe the first reported synovial myxosarcoma affecting the scapulohumeral joint of a small dog.

Mediastinal Ectopic Thyroid Carcinoma and Concurrent Multinodular Pulmonary Fibrosis in a Horse.

A 30-year-old Standardbred gelding was referred for chronic pleural effusion. Thoracic ultrasound revealed marked bilateral pleural effusion and a large heterogeneous mass within the cranial mediastinum, which extended from the right 5th to the 11th intercostal space. Subsequently, on thoracic radiographs, the cranial mediastinal mass was confirmed, and a nodular interstitial pattern was identified in the lungs. Because of progressive clinical deterioration of the patient, the owners elected humane euthanasia and necropsy was performed. The mediastinal mass was consistent with an ectopic thyroid carcinoma, and the pulmonary nodules represented equine multinodular pulmonary fibrosis (EMPF). This case report describes a type of mediastinal tumor not previously described in horses. Moreover, it shows the need of including EMPF as a possible differential diagnosis for a nodular interstitial pulmonary pattern in conjunction with a mediastinal or other masses.

Adenoviral gene transfer of endothelin-1 in the lung induces pulmonary fibrosis through the activation of focal adhesion kinase.

Endothelin-1 (ET-1) has been implicated in the development of pulmonary fibrosis, based on its capacity in vitro to promote extracellular matrix (ECM) production and contraction, and on studies showing elevated expression of ET-1 and its receptors in patients with pulmonary fibrosis. However, the in vivo fibrogenic effect of ET-1 is not well characterized. We used the adenoviral-mediated gene transfer of ET-1 to overexpress ET-1 transiently in murine lungs by intratracheal administration. An increased expression of ET-1 for 3 to 10 days after injection resulted in a moderate but reversible fibrotic response, peaking on Day 14 after infection and characterized by the deposition of ECM components, myofibroblast formation, and a significant inflammatory infiltrate, mainly in the peribronchiolar/perivascular region. Adenoviral-mediated ET-1 overexpression activated focal adhesion kinase (FAK) both in vitro, using primary murine lung fibroblasts, and in vivo, intratracheally administered in the lungs of mice. The inhibition of FAK with the compound PF-562,271 prevented ET-1-mediated collagen deposition and myofibroblast formation, thereby preventing the development of lung fibrosis. In conclusion, we demonstrate that the overexpression of ET-1 directly in the lungs of mice can initiate a fibrogenic response characterized by increased ECM deposition and myofibroblast formation, and that this effect of ET-1 can be prevented by inhibition of FAK. Our data suggest that the ET-1/FAK axis may contribute importantly to the pathogenesis of fibrotic disorders, and highlight FAK as a potential therapeutic target in these devastating diseases.

Inhibition of focal adhesion kinase prevents experimental lung fibrosis and myofibroblast formation.

OBJECTIVE: Enhanced adhesive signaling, including activation of focal adhesion kinase (FAK), is a hallmark of fibroblasts from lung fibrosis patients, and FAK has therefore been hypothesized to be a key mediator of this disease. This study was undertaken to characterize the contribution of FAK to the development of pulmonary fibrosis both in vivo and in vitro. METHODS: FAK expression and activity were analyzed in lung tissue samples from lung fibrosis patients by immunohistochemistry. Mice orally treated with the FAK inhibitor PF-562,271, or with small interfering RNA (siRNA)-mediated silencing of FAK were exposed to intratracheally instilled bleomycin to induce lung fibrosis, and lungs were harvested for histologic and biochemical analysis. Using endothelin 1 (ET-1) as a stimulus, cell adhesion and contraction, as well as profibrotic gene expression, were studied in fibroblasts isolated from wild-type and FAK-deficient mouse embryos. ET-1-mediated FAK activation and gene expression were studied in primary mouse lung fibroblasts, as well as in wild-type and ß1 integrin-deficient mouse fibroblasts. RESULTS: FAK expression and activity were up-regulated in fibroblast foci and remodeled vessels from lung fibrosis patients. Pharmacologic or siRNA-mediated targeting of FAK resulted in marked abrogation of bleomycin-induced lung fibrosis in mice. Loss of FAK impaired the acquisition of a profibrotic phenotype in response to ET-1. Profibrotic gene expression leading to myofibroblast differentiation required cell adhesion, and was driven by JNK activation through ß1 integrin/FAK signaling. CONCLUSION: These results implicate FAK as a central mediator of fibrogenesis, and highlight this kinase as a potential therapeutic target in fibrotic diseases.

The non-canonical NOTCH ligand DLK1 exhibits a novel vascular role as a strong inhibitor of angiogenesis.

AIMS: The epidermal growth factor-like protein Delta-like 1 (DLK1) regulates multiple differentiation processes. It resembles NOTCH ligands structurally and is considered a non-canonical ligand. Given the crucial role of the NOTCH pathway in angiogenesis, we hypothesized that DLK1 could regulate angiogenesis by interfering with NOTCH. We therefore investigated the expression and function of DLK1 in the vascular endothelium and its role in the regulation of angiogenesis. METHODS AND RESULTS: We report DLK1 expression in the endothelium of different species, including human, cow, pig, and mouse. Angiogenesis was studied by using in vitro and in vivo models of angiotube formation in endothelial cells, retinal phenotypes in Dlk1-null mice, and vessel development in zebrafish. DLK1 overexpression strongly inhibited angiotube formation, whereas lung endothelial cells from Dlk1-null mice were highly angiogenic. In vivo studies demonstrated DLK1-mediated inhibition of neovessel formation and revealed an altered pattern of angiogenesis in the retinas of Dlk1-null mice. The expression of human DLK1 in zebrafish embryos severely altered the formation of intersegmental vessels, while knockdown of the orthologous gene was associated with ectopic and increased tumour-induced angiogenesis. NOTCH-dependent signalling as determined by gene expression reporters was inhibited by the presence of DLK1 in vascular endothelial cells. In contrast, Dlk1-null mice showed increased levels of NOTCH downstream targets, such as Snail and Slug. CONCLUSION: Our results unveil a novel inhibitory role for DLK1 in the regulation of angiogenesis, mediated by antagonism of the NOTCH pathway, and establish the basis for investigating its action in pathological settings.

Endothelin 1 contributes to the effect of transforming growth factor beta1 on wound repair and skin fibrosis.

OBJECTIVE: To characterize the pathways induced by transforming growth factor beta1 (TGFbeta1) that lead to the expression of endothelin 1 (ET-1) in human dermal fibroblasts, and to study the effects of TGFbeta1 and ET-1 on the acquisition of a profibrotic phenotype and assess the contribution of the TGFbeta1/ET-1 axis to skin wound healing and fibrosis in vivo. METHODS: The mechanism of induction of ET-1 expression by TGFbeta1 and its effect on the expression of alpha-smooth muscle actin and type I collagen were studied in human dermal fibroblasts, in experiments involving the TGFbeta receptor inhibitor GW788388 and the ET receptor antagonist bosentan, by real-time reverse transcription-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay, immunofluorescence, Western blotting, and promoter/reporter transient transfection analyses. Experiments assessing dermal wound healing in mice were performed with adenovirus-driven overexpression of active TGFbeta1 and ET-1, with or without treatment with bosentan. The contributions of TGFbeta1 and ET-1 to the fibrotic response were also assessed in a mouse model of bleomycin-induced skin fibrosis, by histologic, immunohistochemical, RT-PCR, and protein analyses. RESULTS: TGFbeta1 induced ET-1 expression in human dermal fibroblasts through Smad- and activator protein 1/JNK-dependent signaling. The ability of TGFbeta1 to induce the expression of profibrotic genes was dependent on ET-1. Adenovirus-mediated overexpression of TGFbeta1 and ET-1 in mouse skin was associated with accelerated wound closure, increased fibrogenesis, and excessive scarring. Treatment with bosentan prevented the effects of TGFbeta1. In the bleomycin-induced fibrosis model, treatment with GW788388 and bosentan prevented the fibrotic response. CONCLUSION: Our results strongly support the notion that the TGFbeta1/ET-1 axis has a role in wound repair and skin fibrosis. ET-1 receptor antagonists, such as bosentan, may represent a useful therapeutic tool in the treatment of excessive scarring and fibrosis-related diseases.

Progestogen treatments for cycle management in a sheep model of assisted conception affect the growth patterns, the expression of luteinizing hormone receptors, and the progesterone secretion of induced corpora lutea.

OBJECTIVE: To determine, in a sheep model, the effect of a short-term progestative treatment on growth dynamics and functionality of induced corpora lutea. DESIGN: Observational, model study. SETTING: Public university. PATIENT(S): Sixty adult female sheep. INTERVENTION(S): Synchronization and induction of ovulation with progestogens and prostaglandin analogues; ovarian ultrasonography, blood sampling, and ovariectomy. MAIN OUTCOME MEASURE(S): Determination of pituitary function and morphologic characteristics, expression of luteinizing hormone (LH) receptors, and progesterone secretion of corpora lutea. RESULT(S): The use of progestative pretreatments for assisted conception affect the growth patterns, the expression of LH receptors, and the progesterone secretion of induced corpora lutea. CONCLUSION(S): The current study indicates, in a sheep model, the existence of deleterious effects from progestogens on functionality of induced corpora lutea.