Cytotoxic mAb from Rheumatic Carditis Recognizes Heart Valves and Laminin

Anti-streptococcal antibodies cross-reactive with N-acetyl-bD-glucosamine (GlcNAc) and myosin are present in the sera of patients with rheumatic fever (RF). However, their role in tissue injury is not clear. In this study, we show that anti-GlcNAc/anti-myosin mAb 3.B6 from a rheumatic carditis patient was cytotoxic for human endothelial cell lines and reacted with human valvular endothelium and underlying basement membrane. Reactivity of mAb 3.B6 with the valve was inhibited by human cardiac myosin \u3e laminin \u3e GlcNAc. The mAb 3.B6 epitopes were localized in fragments of human cardiac myosin, including heavy meromyosin (HMM), the S1 subfragment, and two light meromyosin (LMM) peptides containing amino acid sequences KEALISSLTRGKLTYTQQ (LMM 1) and SERVQLLHSQNTSLINQK (LMM 33). A novel feature of mAb 3.B6 was its reactivity with the extracellular matrix protein laminin, which may explain its reactivity with the valve surface. A laminin A-chain peptide (HTQNT) that includes homology to LMM33 inhibited the reactivity of mAb 3.B6 with human valve. These data support the hypothesis that cross-reactive antibodies in rheumatic carditis cause injury at the endothelium and underlying matrix of the valve

Lactate Dehydrogenase-B Is Silenced by Promoter Methylation in a High Frequency of Human Breast Cancers

Objective: Under normoxia, non-malignant cells rely on oxidative phosphorylation for their ATP production, whereas cancer cells rely on Glycolysis; a phenomenon known as the Warburg effect. We aimed to elucidate the mechanisms contributing to the Warburg effect in human breast cancer. Experimental design: Lactate Dehydrogenase (LDH) isoenzymes were profiled using zymography. LDH-B subunit expression was assessed by reverse transcription PCR in cells, and by Immunohistochemistry in breast tissues. LDH-B promoter methylation was assessed by sequencing bisulfite modified DNA. Results: Absent or decreased expression of LDH isoenzymes 1-4, were seen in T-47D and MCF7 cells. Absence of LDH-B mRNA was seen in T-47D cells, and its expression was restored following treatment with the demethylating agent 5'Azacytadine. LDH-B promoter methylation was identified in T-47D and MCF7 cells, and in 25/ 25 cases of breast cancer tissues, but not in 5/ 5 cases of normal breast tissues. Absent immuno-expression of LDH-B protein (<10% cells stained), was seen in 23/ 26 (88%) breast cancer cases, and in 4/8 cases of adjacent ductal carcinoma in situ lesions. Exposure of breast cancer cells to hypoxia (1% O2), for 48 hours resulted in significant increases in lactate levels in both MCF7 (14.0 fold, p = 0.002), and T-47D cells (2.9 fold, p = 0.009), but not in MDA-MB-436 (-0.9 fold, p = 0.229), or MCF10AT (1.2 fold, p = 0.09) cells. Conclusions: Loss of LDH-B expression is an early and frequent event in human breast cancer occurring due to promoter methylation, and is likely to contribute to an enhanced glycolysis of cancer cells under hypoxia

Metabolism within the tumor microenvironment and its implication on cancer progression: an ongoing therapeutic target

Since reprogramming energy metabolism is considered a new hallmark of cancer, tumor metabolism is again in the spotlight of cancer research. Many studies have been carried out and many possible therapies have been developed in the last years. However, tumor cells are not alone. A series of extracellular components and stromal cells, such as endothelial cells, cancer-associated fibroblasts, tumor-associated macrophages and tumor-infiltrating T cells, surround tumor cells in the so-called tumor microenvironment. Metabolic features of these cells are being studied in deep in order to find relationships between metabolism within the tumor microenvironment and tumor progression. Moreover, it cannot be forgotten that tumor growth is able to modulate host metabolism and homeostasis, so that tumor microenvironment is not the whole story. Importantly, the metabolic switch in cancer is just a consequence of the flexibility and adaptability of metabolism and should not be surprising. Treatments of cancer patients with combined therapies including anti-tumor agents with those targeting stromal cell metabolism, anti-angiogenic drugs and/or immunotherapy are being developed as promising therapeutics.Mª Carmen Ocaña is recipient of a predoctoral FPU grant from the Spanish Ministry of Education, Culture and Sport. Supported by grants BIO2014-56092-R (MINECO and FEDER), P12-CTS-1507 (Andalusian Government and FEDER) and funds from group BIO-267 (Andalusian Government). The "CIBER de Enfermedades Raras" is an initiative from the ISCIII (Spain). The funders had no role in the study design, data collection and analysis, decision to publish or preparation of the manuscript

RETINAL OXIMETRY IS ALTERED IN EYES WITH CHOROIDAL MELANOMA BUT NOT IN EYES WITH CHOROIDAL NEVI.

To access publisher's full text version of this article click on the hyperlink belowPurpose: To compare retinal vessel oxygenation in eyes with an untreated choroidal nevus or choroidal melanoma. Methods: The affected and fellow eye of patients with an untreated choroidal nevus (n = 42) or choroidal melanoma (n = 45) were investigated using noninvasive retinal oximetry (Oxymap T1). Oxygen saturation of arterioles (ArtSat) and venules (VenSat) was determined, together with the arteriovenous difference (AV-difference). Results: In choroidal nevus patients, retinal oximetry did not differ between the affected and fellow eye: the mean ArtSat was 94.5% and 94.2% (P = 0.56), the VenSat was 60.5% and 61.3% (P = 0.35), and the AV-difference was 34.0% and 32.9% (P = 0.18), respectively. In choroidal melanoma patients, alterations were detected: the mean ArtSat was 94.8% and 93.2% (P = 0.006), the VenSat was 58.0% and 60.0% (P = 0.014), and the AV-difference was 36.8% and 33.2% (P < 0.001), respectively. The largest increase in AV-difference was observed between the retinal halves without the lesion in melanoma eyes compared with the corresponding half in the fellow eye (37.5% vs. 32.1%, P < 0.001). Conclusion: Although retinal oximetry was not significantly altered in eyes with a choroidal nevus, eyes with choroidal melanoma showed an increased ArtSat and decreased VenSat, leading to an increased AV-difference. These changes may be caused by inflammation and a higher metabolism, with larger oxygen consumption, leading to altered blood flow and intraocular oxygen relocation.Leiden University Medical Center Stichting Nederlands Oogheelkundig Onderzoek (SNOO

The Cryptococcus neoformans monocarboxylate transporter Jen4 is responsible for increased 3-bromopyruvate sensitivity

In the last decades, 3-bromopyruvate (3BP) has been intensively studied as a promising anticancer and antimicrobial agent. The transport of this drug inside the cell is a critical step for its toxicity in cancer and microorganisms. The Cryptococcus neoformans is the most sensitive species of microorganisms toward 3BP. Its cells exhibit the highest uptake rate of 3BP among all tested fungal strains. In Saccharomyces cerevisiae cells, the Jen1 transporter was found to be responsible for 3BP sensitivity. The deletion of Jen1 resulted in the abolishment of 3BP mediated transport. We functionally characterized the Jen4 protein, a Jen1 homologue of C. neoformans, and its role in the phenotypic 3BP sensitivity. The deletion of the CNAG_04704 gene, which encodes Jen4, was found to impair the mediated transport of 3BP and decrease 3BP sensitivity. Further heterologous expression of Jen4 in the S. cerevisiae jen1 Delta ady2 Delta strain restored the mediated transport of 3BP. The application of a green fluorescent protein fusion tag with the CNAG_04704, revealed the Jen4 labeled on the plasma membrane. The identification of 3BP transporters in pathogen cells is of great importance for understanding the mechanisms of 3BP action and to anticipate the application of this compound as an antimicrobial drug.This work was supported by the Ministry of Science and Higher Education (Poland) via 'Statutory Research 2018/S/IGM', the strategic program UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569) and was also co-financed by the Polish National Science Center (grant number 2015/19/N/NZ7/00956), by the project PTDC/BIAMIC/5184/2014 funded by national funds through the Fundacao para a Ciencia e Tecnologia (FCT) I.P. and by the European Regional Development Fund (ERDF) through the COMPETE 2020-Programa Operacional Competitividade e Internacionalizacao (POCI). DR acknowledges FCT for the SFRH/BD/96 166/2013 PhD grant