Dedifferentiated Chondrosarcoma Demonstrating Osteosarcomatous Differentiation

BACKGROUND: Dedifferentiated chondrosarcoma (DDC) accounts for a small proportion of chondrosarcomas. They demonstrate aggressive behaviour with a high rate of local recurrence and systemic progression resulting in poor long-term survival rates. Due to its relatively low incidence, previous studies have grouped different histiotypes together to achieve adequate study numbers for analysis. METHODS: This retrospective study examines the clinical course and the role of chemotherapy in the subgroup of patients with DDC where osteosarcoma is the predominant dedifferentiated component. Between 2000-2010, 21 patients were identified. RESULTS: The mean age at presentation was 64 years (range 35-80 years). 12 patients were considered unfit for chemotherapy, whilst 2 patients declined chemotherapy. 5 patients received neoadjuvant chemotherapy, with less than 90% necrosis demonstrated in all these cases. 3 patients received post-operative chemotherapy. The median survival for the entire group was 9.5 months. In the 7 patients who received chemotherapy, the median survival was 17 months, and those who had chemotherapy had a greater median time to local recurrence. CONCLUSION: This study demonstrates that cytotoxic chemotherapy may be offered to appropriately selected patients

LuxS Coexpression Enhances Yields of Recombinant Proteins in Escherichia coli in Part through Posttranscriptional Control of GroEL

Cell-to-cell communication, or quorum sensing (QS), enables cell density-dependent regulation of bacterial gene expression which can be exploited for the autonomous-signal-guided expression of recombinant proteins (C. Y. Tsao, S. Hooshangi, H. C. Wu, J. J. Valdes, and W. E. Bentley, Metab. Eng. 12:291-297, 2010). Earlier observations that the metabolic potential of Escherichia coli is conveyed via the QS signaling molecule autoinducer-2 (AI-2) suggested that the capacity for protein synthesis could also be affected by AI-2 signaling (M. P. DeLisa, J. J. Valdes, and W. E. Bentley, J. Bacteriol. 183:2918-2928, 2001). In this work, we found that simply adding conditioned medium containing high levels of AI-2 at the same time as inducing the synthesis of recombinant proteins doubled the yield of active product. We have hypothesized that AI-2 signaling “conditions” cells as a natural consequence of cell-to-cell communication and that this could tweak the signal transduction cascade to alter the protein synthesis landscape. We inserted luxS (AI-2 synthase) into vectors which cosynthesized proteins of interest (organophosphorus hydrolase [OPH], chloramphenicol acetyltransferase [CAT], or UV-variant green fluorescent protein [GFPuv]) and evaluated the protein expression in luxS-deficient hosts. In this way, we altered the level of luxS in the cells in order to “tune” the synthesis of AI-2. We found conditions in which the protein yield was dramatically increased. Further studies demonstrated coincident upregulation of the chaperone GroEL, which may have facilitated higher yields and is shown for the first time to be positively regulated at the posttranscriptional level by AI-2. This report is the first to demonstrate that the protein synthesis capacity of E. coli can be altered by rewiring quorum sensing circuitry

The innate immune response to coxsackievirus B3 predicts progression to cardiovascular disease and heart failure in male mice

<p>Abstract</p> <p>Background</p> <p>Men are at an increased risk of dying from heart failure caused by inflammatory heart diseases such as atherosclerosis, myocarditis and dilated cardiomyopathy (DCM). We previously showed that macrophages in the spleen are phenotypically distinct in male compared to female mice at 12 h after infection. This innate immune profile mirrors and predicts the cardiac immune response during acute myocarditis.</p> <p>Methods</p> <p>In order to study sex differences in the innate immune response, five male and female BALB/c mice were infected intraperitoneally with coxsackievirus B3 (CVB3) or phosphate buffered saline and their spleens were harvested 12 h later for microarray analysis. Gene expression was determined using an Affymetrix Mouse Gene 1.0 ST Array. Significant gene changes were verified by quantitative real-time polymerase chain reaction or ELISA.</p> <p>Results</p> <p>During the innate immune response to CVB3 infection, infected males had higher splenic expression of genes which are important in regulating the influx of cholesterol into macrophages, such as phospholipase A₂(PLA₂) and the macrophage scavenger receptor compared to the infected females. We also observed a higher expression in infected males compared to infected females of squalene synthase, an enzyme used to generate cholesterol within cells, and Cyp2e1, an enzyme important in metabolizing cholesterol and steroids. Infected males also had decreased levels of the translocator protein 18 kDa (TSPO), which binds PLA₂and is the rate-limiting step for steroidogenesis, as well as decreased expression of the androgen receptor (AR), which indicates receptor activation. Gene differences were not due to increased viral replication, which was unaltered between sexes.</p> <p>Conclusions</p> <p>We found that, compared to females, male mice had a greater splenic expression of genes which are important for cholesterol metabolism and activation of the AR at 12 h after infection. Activation of the AR has been linked to increased cardiac hypertrophy, atherosclerosis, myocarditis/DCM and heart failure in male mice and humans.</p

Cardiac defects of hypermobile Ehlers-Danlos syndrome and hypermobility spectrum disorders: a retrospective cohort study

BackgroundDefective connective tissue structure may cause individuals with hypermobile Ehlers-Danlos syndrome (hEDS) or hypermobility spectrum disorders (HSD) to develop cardiac defects.MethodsWe conducted a retrospective chart review of adult patients treated in the EDS Clinic from November 1, 2019, to June 20, 2022 to identify those with cardiac defects. Echocardiogram data were collected using a data collection service. All EDS Clinic patients were evaluated by a single physician and diagnosed according to the 2017 EDS diagnostic criteria. Patient demographic, family and cardiac history were extracted from self-reported responses from a REDCap clinical intake questionnaire. Patients with at least 1 available echocardiogram (ECHO) were selected for the study (n = 568).ResultsThe prevalence of aortic root dilation in patients with hEDS was 2.7% and for HSD was 0.6%, with larger measurements for males than females and with age. Based on self-reported cardiac history that was verified from the medical record, patients with hEDS with bradycardia (p = 0.034) or brain aneurysm (p = 0.015) had a significantly larger average adult aortic root z-score. In contrast, patients with HSD that self-reported dysautonomia (p = 0.019) had a significantly larger average aortic root z-score. The prevalence of diagnosed mitral valve prolapse in patients with hEDS was 3.5% and HSD was 1.8%. Variants of uncertain significance were identified in 16 of 84 patients that received genetic testing based on family history.ConclusionsThese data reveal a low prevalence of cardiac defects in a large cohort of well-characterized hEDS and HSD patients. Differences in cardiovascular issues were not observed between patients with hEDS vs. HSD; and our findings suggest that cardiac defects in patients with hEDS or HSD are similar to the general population

Regenerative medicine therapy: adipose derived extracellular vesicles in viral myocarditis

Objective: Myocarditis, inflammation of the heart muscle, is an autoimmune heart disease that can be caused by viruses, bacteria and toxins. Myocarditis can lead to dilated cardiomyopathy (DCM) and heart failure. Currently there are no disease-specific therapies for treating myocarditis or preventing progression to DCM. Adipose Extracellular Vesicles (AEVs) are lipid bilayer nanoparticles that are released into the outside environment of adipocytes and provide promising regenerative potential for inflammatory diseases like myocarditis. Methods: Lipoaspirate was obtained from women and men and AEVs isolated from the lipoaspirate using tangential flow filtration. We injected wild type male BALB/c mice with 250uL AEVs (1×10^10 EV/mL) intraperitoneally or sucrose control on day -1, 0, 1 with viral infection on day 0. Mice were harvested on day 10 post infection at the peak of myocarditis. Results: We found that male mice treated with AEVs from a female patient had a significantly higher body weight (p=0.0003), less calcification in the gut (p=0.001) and less myocardial inflammation (p=0.007) than controls. Mouse hearts analyzed by qRT-PCR revealed that AEV treated mice had significantly lower relative gene expression of cell markers for total immune cells (CD45, p=0.002), macrophages (CD11b, p=0.002, F4/80, p=0.0004); specifically M2 macrophages (Chi313, p=0.003), as well as CD3+ (p=0.007) and CD4+ T cells (p=0.01) than controls. Additionally, we found that mice treated with AEVs from a male patient also had significantly less myocardial inflammation (p=0.01). Conclusion: AEVs could provide an innovative therapy to reduce cardiac inflammation and decrease the risk of developing DCM following myocarditis

Visualizing Interactions along the Escherichia coli Twin-Arginine Translocation Pathway Using Protein Fragment Complementation

The twin-arginine translocation (Tat) pathway is well known for its ability to export fully folded substrate proteins out of the cytoplasm of Gram-negative and Gram-positive bacteria. Studies of this mechanism in Escherichia coli have identified numerous transient protein-protein interactions that guide export-competent proteins through the Tat pathway. To visualize these interactions, we have adapted bimolecular fluorescence complementation (BiFC) to detect protein-protein interactions along the Tat pathway of living cells. Fragments of the yellow fluorescent protein (YFP) were fused to soluble and transmembrane factors that participate in the translocation process including Tat substrates, Tat-specific proofreading chaperones and the integral membrane proteins TatABC that form the translocase. Fluorescence analysis of these YFP chimeras revealed a wide range of interactions such as the one between the Tat substrate dimethyl sulfoxide reductase (DmsA) and its dedicated proofreading chaperone DmsD. In addition, BiFC analysis illuminated homo- and hetero-oligomeric complexes of the TatA, TatB and TatC integral membrane proteins that were consistent with the current model of translocase assembly. In the case of TatBC assemblies, we provide the first evidence that these complexes are co-localized at the cell poles. Finally, we used this BiFC approach to capture interactions between the putative Tat receptor complex formed by TatBC and the DmsA substrate or its dedicated chaperone DmsD. Our results demonstrate that BiFC is a powerful approach for studying cytoplasmic and inner membrane interactions underlying bacterial secretory pathways

Sex and age differences in sST2 in cardiovascular disease

AimsThe goal of this study was to determine whether sex and age differences exist for soluble ST2 (sST2) for several cardiovascular diseases (CVDs).MethodsWe examined sST2 levels using an ELISA kit for myocarditis (n = 303), cardiomyopathy (n = 293), coronary artery disease (CAD) (n = 239), myocardial infarct (MI) (n = 159), and congestive heart failure (CHF) (n = 286) and compared them to controls that did not have CVDs (n = 234).ResultsMyocarditis occurred in this study in relatively young patients around age 40 while the other CVDs occurred more often in older individuals around age 60. We observed a sex difference in sST2 by age only in myocarditis patients (men aged 38, women 46, p = 0.0002), but not for other CVDs. Sera sST2 levels were significantly elevated compared to age-matched controls for all CVDs: myocarditis (p ≤ 0.0001), cardiomyopathy (p = 0.0009), CAD (p = 0.03), MI (p = 0.034), and CHF (p &lt; 0.0001) driven by elevated sST2 levels in females for all CVDs except myocarditis, which was elevated in both females (p = 0.002) and males (p ≤ 0.0001). Sex differences in sST2 levels were found for myocarditis and cardiomyopathy but no other CVDs and were higher in males (myocarditis p = 0.0035; cardiomyopathy p = 0.0047). sST2 levels were higher in women with myocarditis over 50 years of age compared to men (p = 0.0004) or women under 50 years of age (p = 0.015). In cardiomyopathy and MI patients, men over 50 had significantly higher levels of sST2 than women (p = 0.012 and p = 0.043, respectively) but sex and age differences were not detected in other CVDs. However, women with cardiomyopathy that experienced early menopause had higher sST2 levels than those who underwent menopause at a natural age range (p = 0.02).ConclusionWe found that sex and age differences in sera sST2 exist for myocarditis, cardiomyopathy, and MI, but were not observed in other CVDs including CAD and CHF. These initial findings in patients with self-reported CVDs indicate that more research is needed into sex and age differences in sST2 levels in individual CVDs

Novel Human Recombinant N-Acetylgalactosamine-6-Sulfate Sulfatase Produced in a Glyco-Engineered Escherichia coli Strain

Mucopolysaccharidosis IVA (MPS IVA) is a lysosomal storage disease caused by mutations in the gene encoding the lysosomal enzyme N-acetylgalactosamine-6-sulfate sulfatase (GALNS), resulting in the accumulation of keratan sulfate (KS) and chondroitin-6-sulfate (C6S). Previously, it was reported the production of an active human recombinant GALNS (rGALNS) in E. coli BL21(DE3). However, this recombinant enzyme was not taken up by HEK293 cells or MPS IVA skin fibroblasts. Here, we leveraged a glyco-engineered E. coli strain to produce a recombinant human GALNS bearing the eukaryotic trimannosyl core N-glycan, Man3GlcNAc2 (rGALNSoptGly). The N-glycosylated GALNS was produced at 100 mL and 1.65 L scales, purified and characterized with respect to pH stability, enzyme kinetic parameters, cell uptake, and KS clearance. The results showed that the addition of trimannosyl core N-glycans enhanced both protein stability and substrate affinity. rGALNSoptGly was capture through a mannose receptor-mediated process. This enzyme was delivered to the lysosome, where it reduced KS storage in human MPS IVA fibroblasts. This study demonstrates the potential of a glyco-engineered E. coli for producing a fully functional GALNS enzyme. It may offer an economic approach for the biosynthesis of a therapeutic glycoprotein that could prove useful for MPS IVA treatment. This strategy could be extended to other lysosomal enzymes that rely on the presence of mannose N-glycans for cell uptake