Significance of the Wnt signaling pathway in coronary artery atherosclerosis.

Introduction: The progression of coronary atherosclerosis is an active and regulated process. The Wnt signaling pathway is thought to play an active role in the pathogenesis of several cardiovascular diseases; however, a better understanding of this system in atherosclerosis is yet to be unraveled. Methods: In this study, real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting were used to quantify the expression of Wnt3a, Wnt5a, and Wnt5b in the human coronary plaque, and immunohistochemistry was used to identify sites of local expression. To determine the pathologic significance of increased Wnt, human vascular smooth muscle cells (vSMCs) were treated with Wnt3a, Wnt5a, and Wnt5b recombinant proteins and assessed for changes in cell differentiation and function. Results: RT-PCR and Western blotting showed a significant increase in the expression of Wnt3a, Wnt5a, Wnt5b, and their receptors in diseased coronary arteries compared with that in non-diseased coronary arteries. Immunohistochemistry revealed an abundant expression of Wnt3a and Wnt5b in diseased coronary arteries, which contrasted with little or no signals in normal coronary arteries. Immunostaining of Wnt3a and Wnt5b was found largely in inflammatory cells and myointimal cells. The treatment of vSMCs with Wnt3a, Wnt5a, and Wnt5b resulted in increased vSMC differentiation, migration, calcification, oxidative stress, and impaired cholesterol handling. Conclusions: This study demonstrates the upregulation of three important members of canonical and non-canonical Wnt signaling pathways and their receptors in coronary atherosclerosis and shows an important role for these molecules in plaque development through increased cellular remodeling and impaired cholesterol handling.

The Role of Wnt/ß-Catenin Pathway Mediators in Aortic Valve Stenosis.

Aortic valve stenosis (AVS) is a prevailing and life-threatening cardiovascular disease in adults over 75 years of age. However, the molecular mechanisms governing the pathogenesis of AVS are yet to be fully unraveled. With accumulating evidence that Wnt signaling plays a key role in the development of AVS, the involvement of Wnt molecules has become an integral study target in AVS pathogenesis. Thus, we hypothesized that the Wnt/ß-catenin pathway mediators, SFRP2, DVL2, GSK3ß and ß-catenin are dysregulated in patients with AVS. Using immunohistochemistry, Real-Time qPCR and Western blotting, we investigated the presence of SFRP2, GSK-3ß, DVL2, and ß-catenin in normal and stenotic human aortic valves. Markedly higher mRNA and protein expression of GSK-3ß, DVL2, ß-catenin and SFRP2 were found in stenotic aortic valves. This was further corroborated by observation of their abundant immunostaining, which displayed strong immunoreactivity in diseased aortic valves. Proteomic analyses of selective GSK3b inhibition in calcifying human aortic valve interstitial cells (HAVICs) revealed enrichment of proteins involved organophosphate metabolism, while reducing the activation of pathogenic biomolecular processes. Lastly, use of the potent calcification inhibitor, Fetuin A, in calcifying HAVICs significantly reduced the expression of Wnt signaling genes Wnt3a, Wnt5a, Wnt5b, and Wnt11. The current findings of altered expression of canonical Wnt signaling in AVS suggest a possible role for regulatory Wnts in AVS. Hence, future studies focused on targeting these molecules are warranted to underline their role in the pathogenesis of the disease.

Preoperative prediction of non-invasive follicular thyroid neoplasm with papillary-like nuclear features: a Canadian single-Centre experience.

BACKGROUND: An international group of experts recommended reclassifying non-invasive follicular variant of papillary thyroid cancers (FVPTC) as 'non-invasive follicular thyroid neoplasm with papillary-like nuclear features' (NIFTP) in April 2016. The purpose of this study was to establish preoperative clinical, laboratory, ultrasonographic, and cytological variables, which can differentiate NIFTP from FVPTC. METHODS: We conducted a retrospective chart review of consecutive patients from a single institution evaluated between January 2012 and December 2017. 203 adult patients underwent lobectomy or total thyroidectomy for a FVPTC during that period. Each patient's medical chart was reviewed and information on pre-operative variables was recorded. An expert pathologist reviewed all surgical specimens and reclassified a subset of FVPTC as NIFTP according to the specific criteria. RESULTS: Overall, 44 patients were included in the NIFTP group and 159 in the non-NIFTP group. Mean age was 50.1 years in the NIFTP group and 50.7 in the non-NIFTP group. Most patients were female (86.4% (38/44) in the NIFTP group vs 79.8% (127/159) in the non-NIFTP group). More patients underwent lobectomy in the NIFTP group (50% (22/44) vs 16.4% (26/159) in the non-NIFTP group, p = < 0.0001). Less patients received radioactive iodine in the NIFTP group (31.8% (14/44) vs 52.2% (83/159) in the non-NIFTP group, p = 0.0177). Preoperative thyroglobulin levels were lower in NIFTP patients (Median 25.55 mcg/L +/- 67.8 vs 76.06 mcg/L +/- 119.8 in Non-NIFTP, p = 0.0104). NIFTP nodules were smaller (Mean size 22.97 mm +/- 12.3 vs 25.88 mm +/- 11.2 for non-NIFTP, p = 0.0448) and more often solid than non-NIFTP (93.2% (41/44) vs 74.8% (119/159) for non-NIFTP, p = 0.0067). 2017 ACR TIRADS nodule category of 1-4 on ultrasound had a negative predictive value and a sensitivity of 100% for NIFTP. ROC Curve Analysis demonstrated that a preoperative thyroglobulin level of 31.3 mcg/L had a sensitivity of 75% and a specificity of 62.5% to differentiate NIFTP from non-NIFTP cancers. CONCLUSION: Lower preoperative thyroglobulin levels, smaller nodule size, solid texture and 2017 ACR TIRADS Category of 1-4 are more strongly associated with NIFTP than FVPTC and can favour less invasive surgical options such as lobectomy.

CALCITONIN SECRETORY INDEX AND UNSUSPECTED NODAL DISEASE IN MEDULLARY THYROID CARCINOMA.

OBJECTIVE: Medullary thyroid carcinoma (MTC) is a rare thyroid malignancy originating from parafollicular C-cells with the potential for aggressive behavior. The extent of lymph node (LN) dissection at the time of surgery is controversial, with different schools of thought prevailing. Some systematically perform LN dissections, whereas others base their decision on radiologic evidence of disease and some with the assistance of pre-operative calcitonin (CT) levels. METHODS: We retrospectively assessed the correlation between pre-operative CT levels and clinico-pathologic factors among 42 patients with MTC between 1994 and 2015. Furthermore, we refined the use of pre-operative serum CT levels and explored for the first time a test called the Calcitonin Secretory Index (CSI, ng/mL/mm). RESULTS: Pre-operative CT levels correlated independently with tumor size ( P<.0001), number of metastatic LNs ( P<.01), and increased rates of distant metastasis. The CSI better predicted early LN disease ( P<.045). Patients with early LN metastasis had a CSI >30 ng/mL/mm, a representative threshold above which the surgical cure declines considerably. CONCLUSION: In our experience, pre-operative CT levels and now the CSI appear as sensitive and specific risk stratification markers for MTC. Despite negative findings on dedicated pre-operative neck imaging in addition to total thyroidectomy, a CSI >30 ng/mL/mm would prompt bilateral central node dissection. Due to the small sample size, our study provides preliminary evidence of the value of CSI in clinical practice. ABBREVIATIONS: ANOVA = analysis of variance; ATA = American Thyroid Association; CSI = Calcitonin Secretory Index; CT = calcitonin; LN = lymph node; MTC = medullary thyroid carcinoma; ROC = receiver operating characteristic.

The use of a modified abbé island flap to reconstruct primary lip defects of over 80.

BACKGROUND: Lip reconstruction for defects greater than 80 % present a challenge in maintaining acceptable oral function and good aesthetic results. Abbé flaps offer an excellent reconstructive option but are limited to defects under 65 %. METHODS: We describe a two-stage "modified Abbé island flap" technique whereby a full-thickness myocutaneous flap is combined with a modified Karapandzic flap, allowing for reconstruction of total and near total lip defects. RESULTS: Six patients underwent successful two-stage lower and upper lip reconstruction with this technique. Oral competence and satisfactory aesthetic outcomes were achieved in all six cases. There were no complications. Although microstomia was noted to a certain extent, we argue this impact to be less than the morbidity of a free flap that lacks sphincteric function. CONCLUSION: The "Modified Abbé Island Flap" can be used to reconstruct near-total lip defects using locally innervated, well-vascularized tissues that recreate the oral sphincter and restore oral competence. The combination of the conventional Abbé flap with a modified Karapandzic flap provides reliable results and significantly reduces operating time.

Pharmacological targeting of valosin containing protein (VCP) induces DNA damage and selectively kills canine lymphoma cells.

BACKGROUND: Valosin containing protein (VCP) is a critical mediator of protein homeostasis and may represent a valuable therapeutic target for several forms of cancer. Overexpression of VCP occurs in many cancers, and often in a manner correlating with malignancy and poor outcome. Here, we analyzed VCP expression in canine lymphoma and assessed its potential as a therapeutic target for this disease. METHODS: VCP expression in canine lymphomas was evaluated by immunoblotting and immunohistochemistry. The canine lymphoma cell lines CLBL-1, 17-71 and CL-1 were treated with the VCP inhibitor Eeyarestatin 1 (EER-1) at varying concentrations and times and were assessed for viability by trypan blue exclusion, apoptosis by TUNEL and caspase activity assays, and proliferation by propidium iodide incorporation and FACS. The mechanism of EER-1 action was determined by immunoblotting and immunofluorescence analyses of Lys48 ubiquitin and markers of ER stress (DDIT3), autophagy (SQSTM1, MAP1LC3A) and DNA damage (γH2AFX). TRP53/ATM-dependent signaling pathway activity was assessed by immunoblotting for TRP53 and phospho-TRP53 and real-time RT-PCR measurement of Cdkn1a mRNA. RESULTS: VCP expression levels in canine B cell lymphomas were found to increase with grade. EER-1 treatment killed canine lymphoma cells preferentially over control peripheral blood mononuclear cells. EER-1 treatment of CLBL-1 cells was found to both induce apoptosis and cell cycle arrest in G1. Unexpectedly, EER-1 did not appear to act either by inducing ER stress or inhibiting the aggresome-autophagy pathway. Rather, a rapid and dramatic increase in γH2AFX expression was noted, indicating that EER-1 may act by promoting DNA damage accumulation. Increased TRP53 phosphorylation and Cdkn1a mRNA levels indicated an activation of the TRP53/ATM DNA damage response pathway in response to EER-1, likely contributing to the induction of apoptosis and cell cycle arrest. CONCLUSIONS: These results correlate VCP expression with malignancy in canine B cell lymphoma. The selective activity of EER-1 against lymphoma cells suggests that VCP will represent a clinically useful therapeutic target for the treatment of lymphoma. We further suggest a mechanism of EER-1 action centered on the DNA repair response that may be of central importance for the design and characterization of VCP inhibitory compounds for therapeutic use.