Monocyte (THP-1) Response to Silver Nanoparticles Synthesized with Rumex hymenosepalus Root Extract.

The study, synthesis, and application of nanomaterials in medicine have grown exponentially in recent years. An example of this is the understanding of how nanomaterials activate or regulate the immune system, particularly macrophages. In this work, nanoparticles were synthesized using Rumex hymenosepalus as a reducing agent (AgRhNPs). According to thermogravimetric analysis, the metal content of nanoparticles is 55.5% by weight. The size of the particles ranges from 5-26 nm, with an average of 11 nm, and they possess an fcc crystalline structure. The presence of extract molecules on the nanomaterial was confirmed by UV-Vis and FTIR. It was found by UPLC-qTOF that the most abundant compounds in Rh extract are flavonols, flavones, isoflavones, chalcones, and anthocyanidins. The viability and apoptosis of the THP-1 cell line were evaluated for AgRhNPs, commercial nanoparticles (AgCNPs), and Rh extract. The results indicate a minimal cytotoxic and apoptotic effect at a concentration of 12.5 µg/mL for both nanoparticles and 25 µg/mL for Rh extract. The interaction of the THP-1 cell line and treatments was used to evaluate the polarization of monocyte subsets in conjunction with an evaluation of CCR2, Tie-2, and Arg-1 expression. The AgRhNPs nanoparticles and Rh extract neither exhibited cytotoxicity in the THP-1 monocyte cell line. Additionally, the treatments mentioned above exhibited anti-inflammatory effects by maintaining the classical monocyte phenotype CD14++CD16, reducing pro-inflammatory interleukin IL-6 production, and increasing IL-4 production.

Zingiber officinale-Derived Extracellular Vesicles Attenuate Bleomycin-Induced Pulmonary Fibrosis Trough Antioxidant, Anti-Inflammatory and Protease Activity in a Mouse Model.

Idiopathic pulmonary fibrosis (IPF) is the most frequent and severe idiopathic interstitial pneumonia. It is a chronic and progressive disease with a poor prognosis and is a major cause of morbidity and mortality. This disease has no cure; therefore, there is a clinical need to search for alternative treatments with greater efficacy. In this study, we aimed to evaluate the effect of extracellular vesicles (EVs) from Zingiber officinale (EVZO) in a murine model of bleomycin (BLM)-induced IPF administered through an osmotic minipump. EVZO had an average size of 373 nm and a spherical morphology, as identified by scanning electron microscopy. Label-free proteomic analysis of EVZOs was performed by liquid chromatography coupled to mass spectrometry, and 20 proteins were identified. In addition, we demonstrated the protease activity of EVZO by gelatin-degrading zymography assay and the superoxide dismutase (SOD) activity of EVZO by an enzymatic assay. In the BLM-induced IPF mouse model, nasal administration of 50 µg of EVZO induced recovery of alveolar space size and decreased cellular infiltrate, collagen deposition, and expression of α-SMA-positive cells. Additionally, EVZO inhibited inflammatory markers such as iNOS and COX-2, lipid peroxidation, and apoptotic cells. These results show that EVZO may represent a novel natural delivery mechanism to treat IPF.

Fiebre manchada por Rickettsia rickettsii en las Américas: un problema creciente de salud pública / Rickettsia rickettsii spotted fever in the Americas: a growing public health problem

El comportamiento epidemiológico de la fiebre manchada por Rickettsia rickettsii constituye un desafío para los sistemas de salud del continente americano. Es un padecimiento de relevancia médica por la letalidad que provoca si no es diagnosticado ni tratado oportunamente. Aunque cualquier persona es susceptible a la infección, algunos grupos poblacionales son más vulnerables debido a un mayor contacto con la garrapata transmisora, entre ellos los niños, quienes tienen mayor morbilidad por lo que se asocian con resultados fatales. En su origen participa una multitud de factores biológicos, ecológicos y sociales, interrelacionados complejamente, y cuyo abordaje requiere de intervenciones integradas y multidisciplinarias. La incidencia de la enfermedad puede continuar aumentando en la región, de modo que su ocurrencia actual constituye un llamado urgente para la acción regional. Acciones preventivas que disminuyan el contacto con garrapatas e incrementen la sospecha temprana de la enfermedad, son prioritarias en la agenda de salud de varias naciones de las Américas.

Rocky mountain spotted fever is a public health problem in America. The disease remains as a challenge for Health Systems at regional level. It is an illness of medical relevance due to its high case-fatality rate when it is not diagnosed and treated early. Although anyone is susceptible to infection, some groups are more vulnerable due to increased exposure to ticks, including children who have higher morbidity and fatal outcomes. A myriad of biological, ecological and social factors, complexly interrelated, are associated with its epidemiological pattern, which requires integrated and multidisciplinary interventions at different levels. The incidence of the disease may continue to increase in the region and its actual occurrence required an urgent call for regional action. Preventive actions that reduce contact with ticks and increase early disease suspicion should be priorities in the health agenda of various nations in America.

Role of arachidonic acid metabolism in Stat5 activation induced by oleic acid in MDA-MB-231 breast cancer cells.

Epidemiological studies and animal models suggest an association between high levels of dietary fat intake and an increased risk of breast cancer. In breast cancer cells, the free fatty acid oleic acid (OLA) induces proliferation, migration, invasion and an increase of MMP-9 secretion. However, the role of OLA on Stat5 activation and the participation of COX-2 and LOXs activity in Stat5 activation induced by OLA remain to be investigated. We demonstrate here that stimulation of MDA-MB-231 breast cancer cells with 100 µM OLA induces Stat5 phosphorylation at Tyr-694 and an increase of Stat5-DNA complex formation. The Stat5 DNA-binding activity requires COX-2, LOXs, metalloproteinases and Src activities. In addition, OLA induces cell migration through a Stat5-dependent pathway. In summary, our findings establish that OLA induces cell migration through a Stat5-dependent pathway and that Stat5 activation requires AA metabolites in MDA-MB-231 breast cancer cells.

Evolution and some functions of the NprR-NprRB quorum-sensing system in the Bacillus cereus group.

Quorum-sensing (QS) is a bacterial mechanism for regulation of gene expression in response to cell density. In Gram-positive bacteria, oligopeptides are the signaling molecules to elicit QS. The RNPP protein family (Rap, NprR, PlcR, and PrgX) are intracellular QS receptors that bind directly to their specific signaling peptide for regulating the transcription of several genes. NprR is the activator of a neutral protease in Bacillus subtilis, and it has been recently related to sporulation, cry genes transcription and extracellular protease activity in strains from the B. cereus group. In the B. thuringiensis genome, downstream nprR, a gene encoding a putative QS signaling propeptide (nprRB) was found. We hypothesized that the nprR and nprRB co-evolved because of their coordinated function in the B. cereus group. A phylogenetic tree of nucleotide sequences of nprR revealed six pherotypes, each corresponding to one putative mature NprRB sequence. The nprR tree does not match the current taxonomic grouping of the B. cereus group or the phylogenetic arrangement obtained when using MLST markers from the same strains. SKPDI and other synthetic peptides encoded in the nprRB gene from B. thuringiensis serovar thuringiensis strain 8741 had effect on temporal regulation of sporulation and expression of a cry1Aa'Z transcriptional fusion, but those peptides that stimulated earlier detection of spores decreased cry1Aa expression suggesting that NprR may either activate or repress the transcription of different genes.

Role of DDR1 in the gelatinases secretion induced by native type IV collagen in MDA-MB-231 breast cancer cells.

Discoidin domain receptors (DDRs) are receptor tyrosine kinases that get activated by collagens in its native triple-helical form. In mammalian cells, DDR family consists of two members, namely DDR1 and DDR2, which mediates migration and proliferation of several cell types. DDR1 is activated by native type IV collagen and overexpressed in human breast cancer. Type IV collagen is the main component of basement membrane (BM), and the ability to degrade and penetrate BM is related with an increased potential for invasion and metastasis. Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that collectively are capable of degrading all components of the extracellular matrix, including the BM. In breast cancer cells, denatured type IV collagen induces MMP-9 secretion and invasion. However, the role of DDR1 in the regulation of gelatinases (MMP-2 and -9) secretion and invasion in breast cancer cells remains to be studied. We demonstrate here that native type IV collagen induces MMP-2 and -9 secretions and invasion through a DDR1 and Src-dependent pathway, together with an increase of MMP-2 and -9-cell surface levels. MMP-2 and -9 secretions require PKC kinase activity, epidermal growth factor receptor (EGFR) activation, arachidonic acid (AA) production and AA metabolites in MDA-MB-231 breast cancer cells. In summary, our data demonstrate, for the first time, that DDR1 mediates MMP-2 and -9 secretions and invasion induced by native type IV collagen in MDA-MB-231 breast cancer cells.

Native type IV collagen induces cell migration through a CD9 and DDR1-dependent pathway in MDA-MB-231 breast cancer cells.

CD9 is a member of the tetraspanin family and is widely expressed in the plasma membrane of several cell types as well as malignant cells. CD9 associates with a number of transmembrane proteins, which facilitates biological processes, including cell signaling, adhesion, migration and proliferation. DDR1 is activated by native type IV collagen and overexpressed in human breast cancer. Type IV collagen is the main component of basement membranes, and may interact with cell surface biomolecules, promoting adhesion and motility. However, the role of DDR1 and type IV collagen in the regulation of CD9-cell surface levels and migration in breast cancer cells has not been studied in detail. We demonstrate here that native type IV collagen induces a transient increase of CD9-cell surface levels through a DDR1-dependent pathway in MDA-MB-231 breast cancer cells, as revealed by flow cytometry and Western blotting using specific antibodies that recognize CD9. In contrast, type IV collagen does not induce any increase of CD9-cell surface levels in the mammary non-tumorigenic epithelial cells MCF10A and MCF12A. Transient increase of CD9-cell surface levels is coupled with clathrin-mediated endocytosis and it is dependent of DDR1 expression. In addition, type IV collagen induces cell migration through a DDR1 and CD9-dependent pathway. In summary, our data demonstrate, for the first time, that native type IV collagen induces a transient increase of CD9-cell surface levels and cell migration through a DDR1 and CD9-dependent pathway in MDA-MB-231 breast cancer cells.

Oleic acid promotes MMP-9 secretion and invasion in breast cancer cells.

Epidemiological and animal studies suggest an association between dietary fatty acids and an increase risk of developing breast cancer. Obesity, which is characterized by hyperlipidemia and an elevation of circulating free fatty acids (FFAs), is also associated with enhanced cancer risk. In breast cancer cells, the FFA oleic acid (OA) induces migration, proliferation, prolong survival, invasion, an increase in cellular Ca(2+) concentration, MEK1/2, ERK1/2, FAK and Src activation. However, the role of OA on MMP-9 secretion and invasion has not been studied in detail. We demonstrate here that stimulation of MDA-MB-231 breast cancer cells with 200 µM OA induces an increase on MMP-9 secretion through a PKC, Src, and EGFR-dependent pathway, as revealed by gelatin zymography assays. Furthermore, microtubule network mediates MMP-9 secretion induced by OA. In contrast, OA does not induce an increase on MMP-9 secretion in MCF10A cells, whereas it does not induce MMP-9 secretion in MCF12A mammary non-tumorigenic epithelial cells. In addition, OA induces invasion through an EGFR, Gi/Go proteins, MMPs, PKC and Src-dependent pathway, but it is not able to promote invasion in non-invasive MCF-7 breast cancer cells. In summary, our findings demonstrate that OA promotes an increase on MMP-9 secretion and invasion through a PKC, Src, and EGFR-dependent pathway in breast cancer cells.

Arachidonic acid promotes epithelial-to-mesenchymal-like transition in mammary epithelial cells MCF10A.

Epidemiological studies and animal models suggest an association between high levels of dietary fat intake and an increased risk of breast cancer. Cancer progression requires the development of metastasis, which is characterized by an increase in cell motility and invasion. Epithelial-to-mesenchymal transition (EMT) is a process, by which epithelial cells are transdifferentiated to a more mesenchymal state. A similar process takes place during tumor progression, when carcinoma cells stably or transiently lose epithelial polarities and acquire a mesenchymal phenotype. Arachidonic acid (AA) is a fatty acid that mediates cellular processes, such as cell survival, angiogenesis, chemotaxis, mitogenesis, migration and apoptosis. However, the role of AA on the EMT process in human mammary epithelial cells remains to be studied. We demonstrate here that AA promotes an increase in vimentin and N-cadherin expression, MMP-9 secretion, a decrease in E-cadherin junctional levels, and the activation of FAK, Src and NF-kappaB in MCF10A cells. Furthermore, AA also promotes cell migration in an Src kinase activity-dependent fashion. In conclusion, our results demonstrate, for the first time, that AA promotes an epithelial-to-mesenchymal-like transition in MCF10A human mammary non-tumorigenic epithelial cells.

Oleic acid promotes migration on MDA-MB-231 breast cancer cells through an arachidonic acid-dependent pathway.

An association between dietary fatty, obesity and an increased risk of developing breast cancer has been suggested. In breast cancer cells, free fatty acids (FFAs) mediate biological effects including cell proliferation and ERK1/2 activation. However, the contribution of FFAs to tumor progression and metastasis through the regulation of cell migration has not been studied. We demonstrated here that stimulation on MDA-MB-231 breast cancer cells with oleic acid (OA) promotes an increase in focal adhesion kinase (FAK) phosphorylation, as revealed by site-specific antibodies that recognize the phosphorylation state of FAK at tyrosine-397 (Tyr-397), Tyr-577 and in vitro kinase assays. OA also promotes the migration of MDA-MB-231 cells. Treatment with Gi/Go proteins, phospholipase C (PLC), lipoxygenases (LOXs) and Src inhibitor prevents FAK phosphorylation and cell migration. In summary, our findings delineate a new signal transduction pathway, where OA mediates the production of arachidonic acid (AA), and then AA metabolites mediate FAK phosphorylation and cell migration in MDA-MB-231 breast cancer cells.

Oleic acid induces ERK1/2 activation and AP-1 DNA binding activity through a mechanism involving Src kinase and EGFR transactivation in breast cancer cells.

GPR40 and GPR120 are G-protein-coupled receptors that can be activated by medium- and long-chain fatty acids. GPR40 is expressed in several breast cancer cell lines and its stimulation with oleic acid (OA) induces cell proliferation. However, the signal transduction pathways activated by OA have not been studied in detail. Our results demonstrate that both GPR40 and GPR120 are expressed in MCF-7 cells. Stimulation of MCF-7 and MDA-MB-231 cells with OA promoted the phosphorylation of ERK1/2 at Thr-202 and Tyr-204 and the formation of AP-1-DNA complex in a fashion dependent of Src kinase activity and EGFR transactivation. Furthermore, proliferation induced by OA is restricted to breast cancer cells in a fashion dependent of ERK1/2 activation and matrix metalloproteinases. In summary, our data indicate that proliferation induced by OA is restricted to breast cancer cells, and that ERK1/2 activation and AP-1-DNA complex formation are mediated by Src family kinases and transactivation of EGFR.