Effect of new thiazolidine derivatives LPSF/GQ-02 and LPSF/GQ-16 on atherosclerotic lesions in LDL receptor-deficient mice (LDLR−/−)

BackgroundAtherosclerotic cardiovascular disease is a chronic inflammatory condition. Thiazolidinediones (TZDs) are used to enhance sensitivity to insulin and have demonstrated a protective effect over a variety of cardiovascular markers and risk factors. Controversially, the TZDs are associated with the development of heart failure. Thus, lines of research have invested in the search for new molecules in order to obtain more selective and less harmful treatment alternatives for the pathogenesis of atherosclerosis and its risk factors.MethodsAnimals were fed a diet rich in fat for 10 weeks. In the last 2 weeks, animals received either pioglitazone, LPSF/GQ-02, or LPSF/GQ-16 daily through gavage. At the end of the treatment, blood was collected for biochemical analysis and the aortas were dissected for subsequent analyses.ResultsNo changes in the blood lipid profile were found following the use of the drugs in comparison to the control. However, the new thiazolidine derivatives were more efficient in improving insulin resistance in comparison to pioglitazone and the control group. Morphometric analyses revealed that neither pioglitazone nor LPSF/GQ16 led to satisfactory effects over atherosclerosis. However, LPSF/GQ-02 led to a reduction in area of the atherosclerotic lesions. Ultrastructural analyses revealed extensive degeneration of the endothelium and an increase in apoptotic cells in the subendothelial space following the use of pioglitazone and LPSF/GQ-16. However, LPSF/GQ-02 caused minimal cell alterations in the aortic endothelium. Regarding markers, endothelial nitric oxide synthase (eNOS) and matrix metalloproteinase 9 (MMP-9), LPSF/GQ-16, and pioglitazone exerted similar effects, increasing the expression of MMP-9, and had no effect on the expression of eNOS compared with the control group. On the other hand, LPSF/GQ-02 was effective in reducing the expression of MMP-9 and increased eNOS significantly.ConclusionsThe results suggest that the new thiazolidine derivative LPSF/GQ-02 is a promising candidate for the treatment of atherosclerosis.     

Intermediate expression of CCRL1 reveals novel subpopulations of medullary thymic epithelial cells that emerge in the postnatal thymus

Cortical and medullary thymic epithelial cells (cTECs and mTECs, respectively) provide inductive microenvironments for T‐cell development and selection. The differentiation pathway of cTEC/mTEC lineages downstream of common bipotent progenitors at discrete stages of development remains unresolved. Using IL‐7/CCRL1 dual reporter mice that identify specialized TEC subsets, we show that the stepwise acquisition of chemokine (C–C motif) receptor‐like 1 (CCRL1) is a late determinant of cTEC differentiation. Although cTECs expressing high CCRL1 levels (CCRL1^hi) develop normally in immunocompetent and Rag2^?/?thymi, their differentiation is partially blocked in Rag2^?/?Il2rg^?/? counterparts. These results unravel a novel checkpoint in cTEC maturation that is regulated by the cross‐talk between TECs and immature thymocytes. Additionally, we identify new Ulex europaeus agglutinin 1 (UEA)⁺ mTEC subtypes expressing intermediate CCRL1 levels (CCRL1^int) that conspicuously emerge in the postnatal thymus and differentially express Tnfrsf11a, Ccl21, and Aire. While rare in fetal and in Rag2^?/? thymi, CCRL1^int mTECs are restored in Rag2^?/?Marilyn TCR‐Tg mice, indicating that the appearance of postnatal‐restricted mTECs is closely linked with T‐cell selection. Our findings suggest that alternative temporally restricted routes of new mTEC differentiation contribute to the establishment of the medullary niche in the postnatal thymus.     

Secular Trends in Occurrence of Acute Venous Thromboembolism: The Worcester VTE Study (1985-2009)

Background

The clinical epidemiology of venous thromboembolism has changed recently because of advances in identification, prophylaxis, and treatment. We sought to describe secular trends in the occurrence of venous thromboembolism among residents of the Worcester, Massachusetts, metropolitan statistical area.

Methods

Population-based methods were used to monitor trends in event rates of first-time or recurrent venous thromboembolism in 5025 Worcester, Massachusetts, metropolitan statistical area residents who were diagnosed with acute pulmonary embolism or lower-extremity deep vein thrombosis during 9 annual periods between 1985 and 2009. Medical records were reviewed by abstractors and validated by clinicians.

Results

Age- and sex-adjusted annual event rates for first-time venous thromboembolism increased from 73 (95% confidence interval [CI], 64-82) per 100,000 in 1985/1986 to 133 (CI, 122-143) in 2009, primarily because of an increase in pulmonary embolism. The rate of recurrent venous thromboembolism decreased from 39 (CI, 32-45) in 1985/1986 to 19 (CI, 15-23) in 2003, and then increased to 35 (CI, 29-40) in 2009. There was an increasing trend in using noninvasive diagnostic testing, with approximately half of tests being invasive in 1985/1986 and almost all noninvasive by 2009.

Conclusions

Despite advances in identification, prophylaxis, and treatment between 1985 and 2009, the annual event rate of venous thromboembolism has increased and remains high. Although these increases partially may be due to increased sensitivity of diagnostic methods, especially for pulmonary embolism, they also may imply that current prevention and treatment strategies are less than optimal.     

Successful weight loss maintenance: A systematic review of weight control registries

Weight loss maintenance is a major challenge for obesity treatment. Weight control registries can be useful in identifying psychological and behavioural factors that could contribute to better long‐term success. The objective of this study is to describe the existing weight control registries and their participants and identify correlates of weight loss maintenance. A comprehensive search of peer‐reviewed articles published until November 2018 was conducted in PubMed, Web of Science, and Scopus. Studies that reported results from weight control registries were considered. Fifty‐two articles, corresponding to five registries (the United States, Portugal, Germany, Finland, and Greece), were included. Registries differed in inclusion criteria and procedures. Of 51 identified weight loss and maintenance strategies, grouped in 14 domains of the Oxford Food and Activity Behaviors taxonomy, the following were the most frequently reported: having healthy foods available at home, regular breakfast intake, increasing vegetable consumption, decreasing sugary and fatty foods, limiting certain foods, and reducing fat in meals. Increased physical activity was the most consistent positive correlate of weight loss maintenance. To our knowledge, this is the first systematic review of information about successful weight loss maintenance obtained from weight control registries. Key common influential characteristics of success were identified, which can inform future prospective studies and weight management initiatives.     

Vascular smooth muscle cell-derived adiponectin: a paracrine regulator of contractile phenotype

Adiponectin is a cardioprotective adipokine derived predominantly from visceral fat. We recently demonstrated that exogenous adiponectin induces vascular smooth muscle cell (VSMC) differentiation via repression of mTORC1 and FoxO4. Here we report for the first time that VSMC express and secrete adiponectin, which acts in an autocrine and paracrine manner to regulate VSMC contractile phenotype. Adiponectin was found to be expressed in human coronary artery and mouse aortic VSMC. Importantly, siRNA knock-down of endogenous adiponectin in VSMC significantly reduced the expression of VSMC contractile proteins. Contractile protein deficiency was also observed in primary VSMC isolated from Adiponectin(-/-) mice. This deficiency could be rescued by culturing Adiponectin(-/-) VSMC in conditioned media from wild type (WT) VSMC. Moreover, the paracrine effect of VSMC-derived adiponectin was confirmed as adiponectin neutralizing antibody blocked the rescue. Overexpressed adiponectin also exerted paracrine effects on neighboring untransfected VSMC, which was also blocked by adiponectin neutralizing antibody. Interestingly, adiponectin expression was inducible by the PPARγ agonist rosiglitazone. Our data support an important role for VSMC-derived adiponectin in maintaining VSMC contractile phenotype, contributing to critical cardioprotective functions in the vascular wall. This article is part of a Special Issue entitled "Local Signaling in Myocytes".     

Human liver cell spheroids in extended perfusion bioreactor culture for repeated-dose drug testing

Primary cultures of human hepatocyte spheroids are a promising in vitro model for long-term studies of hepatic metabolism and cytotoxicity. The lack of robust methodologies to culture cell spheroids, as well as a poor characterization of human hepatocyte spheroid architecture and liver-specific functionality, have hampered a widespread adoption of this three-dimensional culture format. In this work, an automated perfusion bioreactor was used to obtain and maintain human hepatocyte spheroids. These spheroids were cultured for 3-4 weeks in serum-free conditions, sustaining their phase I enzyme expression and permitting repeated induction during long culture times; rate of albumin and urea synthesis, as well as phase I and II drug-metabolizing enzyme gene expression and activity of spheroid hepatocyte cultures, presented reproducible profiles, despite basal interdonor variability (n = 3 donors). Immunofluorescence microscopy of human hepatocyte spheroids after 3-4 weeks of long-term culture confirmed the presence of the liver-specific markers, hepatocyte nuclear factor 4α, albumin, cytokeratin 18, and cytochrome P450 3A. Moreover, immunostaining of the atypical protein kinase C apical marker, as well as the excretion of a fluorescent dye, evidenced that these spheroids spontaneously assemble a functional bile canaliculi network, extending from the surface to the interior of the spheroids, after 3-4 weeks of culture. Conclusion: Perfusion bioreactor cultures of primary human hepatocyte spheroids maintain a liver-specific activity and architecture and are thus suitable for drug testing in a long-term, repeated-dose format.