Plasma Membrane Lipid Therapy: Disruption of Oncogenic Ras Driven Phenotypes by Membrane Targeted Dietary Bioactives (Mtdb)

Approximately 30-50% of colorectal cancers contain KRas mutations, which confer resistance to standard therapy. A diet high in long-chain n-3 polyunsaturated fatty acids (n-3 PUFA) is generally considered chemoprotective in regard to colon cancer. However, the molecular mechanisms by which n-3 PUFA suppresses tumorigenesis remain to be determined. Therefore, our overall goal is to define the role of n-3 PUFA in the modulation of oncogenic KRas-driven colon cancer. We hypothesized that n-3 PUFA would modify the biophysical properties of the plasma membrane though its incorporation into plasma membrane phospholipids. Utilizing quantitative fluorescence microscopy, we determined that n-3 PUFA reduce the rigidity of the plasma membrane of young adult mouse colonocytes (YAMC), CD3/CD28 activated CD4⁺ T cells, and colonic crypts derived from transgenic Fat-1 mice, which synthesize n-3 PUFA de novo. Interestingly, n-3 PUFA increased the rigidity of cytoskeletal free giant plasma membrane vesicles (GPMVs), derived from the aforementioned samples. Oncogenic Ras signaling is dependent on the formation of specific plasma membrane localized proteolipid complexes. Thus, it is noteworthy in YAMC cells and Drosophila midguts we documented for the first time that n-3 PUFA generates mix clusters of H- and K-Ras isoforms, which signal through ERK less efficiently. This resulted in a reduction of Ras driven colonic phenotypes in mice and Drosophila models. We then assessed the ability of n-3 PUFA to disrupt macropinocytosis, a cellular process in which extra cellular proteins are internalized through dynamic changes in plasma membrane lipids and cytoskeletal proteins. This process provides energy substrates that support the unique metabolic needs of Ras expressing cells. We determined that Ras expression mediates an increase in plasma membrane free cholesterol, which rigidifies the plasma membrane. Attenuating this rigidification by incorporating n-3 PUFA into the plasma membrane disrupted Ras driven macropinocytosis. Overall, we have demonstrated that n-3 PUFA ameliorate oncogenic Ras driven phenotypes through modification of plasma membrane biophysical properties leading to a disruption of Ras signaling. This reduces the ability of tumor cells to acquire energy substrate necessary to maintain its unique metabolic needs. These data contribute to the mechanistic understanding of how n-3 PUFA protect against colon cancer

Immunotherapy of Brain Cancers: The Past, the Present, and Future Directions

Treatment of brain cancers, especially high grade gliomas (WHO stage III and IV) is slowly making progress, but not as fast as medical researchers and the patients would like. Immunotherapy offers the opportunity to allow the patient's own immune system a chance to help eliminate the cancer. Immunotherapy's strength is that it efficiently treats relatively small tumors in experimental animal models. For some patients, immunotherapy has worked for them while not showing long-term toxicity. In this paper, we will trace the history of immunotherapy for brain cancers. We will also highlight some of the possible directions that this field may be taking in the immediate future for improving this therapeutic option

The O-antigen flippase Wzk can substitute for MurJ in peptidoglycan synthesis in Helicobacter pylori and Escherichia coli

The peptidoglycan (PG) cell wall is an essential component of the cell envelope of most bacteria. Biogenesis of PG involves a lipid-linked disaccharide-pentapeptide intermediate called lipid II, which must be translocated across the cytoplasmic membrane after it is synthesized in the inner leaflet of this bilayer. Accordingly, it has been demonstrated that MurJ, the proposed lipid II flippase in Escherichia coli, is required for PG biogenesis, and thereby viability. In contrast, MurJ is not essential in Bacillus subtilis because this bacterium produces AmJ, an unrelated protein that is functionally redundant with MurJ. In this study, we investigated why MurJ is not essential in the prominent gastric pathogen, Helicobacter pylori. We found that in this bacterium, Wzk, the ABC (ATP-binding cassette) transporter that flips the lipid-linked O- or Lewis- antigen precursors across the inner membrane, is redundant with MurJ for cell viability. Heterologous expression of wzk in E. coli also suppresses the lethality caused by the loss of murJ. Furthermore, we show that this cross-species complementation is abolished when Wzk is inactivated by mutations that target a domain predicted to be required for ATPase activity. Our results suggest that Wzk can flip lipid II, implying that Wzk is the flippase with the most relaxed specificity for lipid-linked saccharides ever identified

Challenges of providing biochemistry results in a patient with Evans syndrome

Highlights A case report of in vivo hemolysis in patient with Evans syndrome is described Hemolysis disrupts biochemistry analysis, yielding unreliable results A laboratory designed algorithm ensures results with interpretative comments Close communication between the laboratory and the clinical team is essential A case report of in vivo hemolysis in a female patient with Evans syndrome is described. The patient was admitted with anemia and jaundice and, during her 26-day hospital admission, had 83 samples taken for biochemistry analyses. The laboratory hemolytic index (HI) was frequently elevated due to persistent complement-mediated in vivo hemolysis despite multiple lines of therapy. Initially, the release of many biochemical parameters was blocked per the manufacturer´s recommendations and reported as “sample hemolyzed”. The patient developed severe acute kidney injury, ultimately requiring dialysis. Automated and timely reporting of indicative creatinine and other biochemical results in the context of ongoing hemolysis, therefore, became essential to patient care. Following a review of literature from various sources, a laboratory algorithm was designed to ensure the timely release of numerical biochemical values, where possible, with appropriate interpretative comments appended. Biochemistry, hematology, and nephrology teams were in regular communication to ensure patient samples were rapidly identified, analyzed and validated according to the algorithm, informing timely, safe and appropriate patient care. Ultimately, the patient died due to multiple disease- and treatment-related complications. In conjunction with clinical users, laboratories should plan for situations, such as in vivo hemolysis, where significant unavoidable interferences in biochemistry methodologies may occur in an ongoing manner for certain patients. Reporting categorical or best-estimate biochemistry results in such cases can be safer for patients than failing to report any results. Interpretation of these results by clinical teams requires input from appropriately trained and qualified laboratory personnel

Three Vessel Disease with Left Main Involvement: A Rare Manifestation of Takayasu’s Arteritis

Background: Takayasu’s arteritis is a chronic vasculitis of unknown etiology affecting large vessels. Coronary involvement is rare and myocardial infarction as a presenting symptom has only been described in case reports. Case: We report a case of a 19 year old female diagnosed with Takayasu’s arteritis 2 years prior who came in due to chest pain and heart failure symptoms. ECG showed diffuse ischemia with ST elevation of the inferior wall. Coronary angiogram showed 3 vessel disease with left main involvement. Patient was started on high dose steroids. She then developed an acute stroke in the right posterior cerebral artery territory. She improved with Methylprednisolone pulse therapy and oral methotrexate. She was discharged on Prednisone, Methotrexate and cardiac medications and is stable on follow up. Diagnostics: Coronary angiogram showed ostioproximal stenosis of the distal left main segment, the proximal left anterior descending artery and the proximal left circumflex artery, with the right coronary artery being totally occluded. Two dimensional echocardiogram showed an ejection fraction of 38 percent with multisegmental wall motion abnormalities. CT aortogram showed segmental narrowing of the infrarenal abdominal aorta with multiple ostioproximal stenosis of several aortic branches with extensive collateral formation. MRI showed acute infarction in the right thalamus,right medial temporal and occipital lobes and right cerebellar hemisphere and vermis Conclusion: Takayasu’s arteritis can present with a myriad of vascular complications. The reported incidence of coronary involvement is low. This case highlights the progressive and unpredictable nature of this disease. A high index of clinical suspicion, as well as a meticulous search for the extent of disease severity allows the clinician to individualize treatment options for these patient

Transplant of Tissue-Engineered Artificial Autologous Human Skin in Andalusia: An Example of Coordination and Institutional Collaboration

A new model of tissue-engineered artificial autologous human skin developed in Andalusia is currently being transplanted into patients suffering from large burns within the Andalusian Public Healthcare System. This product is considered an advanced therapy medicinal product (ATMP) in Europe, and its clinical use implies meeting transplant and medicinal product legal requirements, being the Guidelines of Good Manufacturing Practice for ATMPs of particular importance. The preclinical research and clinical translation of the product have represented a technical, regulatory, and organizational challenge, which has taken 10 years since the first preclinical experiments were designed. Twelve patients with large burns, including 3 pediatric patients, have hitherto received artificial autologous skin grafts with an overall survival rate of 75% and positive clinical, homeostatic, and histologic results. Achieving such a milestone within our Healthcare System was possible through a multidisciplinary approach and the joint efforts of multiple publicly funded institutions and units under the coordination of the Andalusian Initiative for Advanced Therapies. In this article, we present the organizational model set up to facilitate collaboration and logistics among the professionals involved, totaling more than 80 people. The similarities between the tissue-engineered artificial autologous human skin transplant and other organ and tissue transplants, in terms of logistic requirements, reveal how regional and hospital transplant coordination have played a crucial role

Novel ion-doped mesoporous glasses for bone tissue engineering: Study of their structural characteristics influenced by the presence of phosphorous oxide

Ion-doped binary SiO2-CaO and ternary SiO2-CaO-P2O5 mesoporous bioactive glasses were synthesized and characterized to evaluate the influence of P2O5 in the glass network structure. Strontium, copper and cobalt oxides in a proportion of 0.8 mol% were selected as dopants because the osteogenic and angiogenic properties reported for these elements. Although the four glass compositions investigated presented analogous textural properties, TEM analysis revealed that the structure of those containing P2O5 exhibited an increased ordered mesoporosity. Furthermore, 29Si NMR revealed that the incorporation of P2O5 increased the network connectivity and that this compound captured the Sr2 +, Cu2 + and Co2 + ions preventing them to behave as modifiers of the silica network. In addition, 31P NMR results revealed that the nature of the cation directly influences the characteristics of the phosphate clusters. In this study, we have proven that phosphorous oxide entraps doping-metallic ions, granting these glasses with a greater mesopores order

Multiphase photo-capillary reactors coated with TiO2 films: preparation, characterization and photocatalytic performance

Quartz capillaries were assessed as multiphase photocatalytic reactors. The tested reaction was the salicylic acid (2-dihidroxibenzoic acid) oxidation. The catalyst (TiO2) was either in slurry or immobilized by sol-gel method onto the capillary wall. All experiments were conducted under oxygen flow and Taylor flow hydrodynamic regime. TiO2 Films were characterized by Raman spectroscopy, diffuse reflectance UV-Vis spectroscopy and scanning electronic microscopy. The effect of two synthesis variables was established. These variables were volumetric ratio of precursors solutions (i-PrO:2-propanol:nitric acid) and number of capillary coating cycles. These variables were found to importantly affect film homogeneity and oxidation rate. The highest initial reaction rate (106.32x10-6 mol dm-3s-1) was obtained when using the TiO2 as film prepared with a precursors volumetric ratio of 1:15:1 and with two coating cycles. For comparison purposes, the same oxidation process was conducted in a stirred reactor and it was found that the reaction rate value is diminished by almost four times in comparison with that obtained under Taylor flow in the capillary reactor. Selectivity was found to be dependant on the type of catalyst addition, slurry or immobilized. Catalytic films employed in this non-common reaction system were 2 reused three times losing less than 10% of their photocatalytic activity. The photonic efficiency was found to be two orders of magnitude higher in the coated capillary reactor than in the slurry stirred reactor.L. Hurtado acknowledges CONACYT-Mexico the scholarship No. 56499. Project PRODEP for advanced oxidation processes is also acknowledged for financial support