The secretome from human-derived mesenchymal stem cells augments the activity of antitumor plant extracts in vitro.

Cancer is understood as a multifactorial disease that involve multiple cell types and phenotypes in the tumor microenvironment (TME). The components of the TME can interact directly or via soluble factors (cytokines, chemokines, growth factors, extracellular vesicles, etc.). Among the cells composing the TME, mesenchymal stem cells (MSCs) appear as a population with debated properties since it has been seen that they can both promote or attenuate tumor progression. For various authors, the main mechanism of interaction of MSCs is through their secretome, the set of molecules secreted into the extracellular milieu, recruiting, and influencing the behavior of other cells in inflammatory environments where they normally reside, such as wounds and tumors. Natural products have been studied as possible cancer treatments, appealing to synergisms between the molecules in their composition; thus, extracts obtained from Petiveria alliacea (Anamu-SC) and Caesalpinia spinosa (P2Et) have been produced and studied previously on different models, showing promising results. The effect of plant extracts on the MSC secretome has been poorly studied, especially in the context of the TME. Here, we studied the effect of Anamu-SC and P2Et extracts in the human adipose-derived MSC (hAMSC)-tumor cell interaction as a TME model. We also investigated the influence of the hAMSC secretome, in combination with these natural products, on tumor cell hallmarks such as viability, clonogenicity, and migration. In addition, hAMSC gene expression and protein synthesis were evaluated for some key factors in tumor progression in the presence of the extracts by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Multiplex, respectively. It was found that the presence of the hAMSC secretome did not affect the cytotoxic or clonogenicity-reducing activities of the natural extracts on cancer cells, and even this secretome can inhibit the migration of these tumor cells, in addition to the fact that the profile of molecules can be modified by natural products. Overall, our findings demonstrate that hAMSC secretome participation in TME interactions can favor the antitumor activities of natural products.

The impact of an annual major recreational boating event on water quality in the Solent Strait.

A long-term historical analysis of the impacts of recreational boating on marine surface water quality during a regatta (Cowes Week) in an internationally crucial waterway, the Solent Strait (Hampshire, UK) is presented. Water quality indicators studied included nitrogen concentration, bacterial indicators, and oxygen saturation, at three sampling sites at/near Cowes during 2001-2019. Findings include that sewage discharge from recreational boats is the key contributor to localised faecal contamination of marine surface waters, putting bathers and shellfisheries at risk. Bathing water quality monitoring and pollution warning systems should be strengthened prior to and during this type of regatta and access to bathing water areas may need to be restricted. These findings have implications for the regulation, future monitoring and management strategies for discharges from recreational boats during extended regattas. Adequate and affordable local facilities for recovering sewage wastewater from recreational boats should be provided alongside appropriate mechanisms for communication to sailors.

Dermo-epidermal organotypic cultures for in vitro evaluation of skin irritation and corrosion.

In recent years, in-vitro skin models for chemical hazard identification have been developed. Most of them consist only of human keratinocytes, neglecting the contribution of other skin constituents. Cultures containing the dermal and epidermal component provide an attractive system to investigate, in a more realistic model, toxicological responses, which represents a distinct advantage over keratinocytes-based models that do not mimic faithfully the in vivo environment. This study aimed to validate dermo-epidermal organotypic cultures (ORGs) as a platform to perform irritation and corrosion tests. Skin models were constructed by seeding keratinocytes on fibroblast-containing fibrin gels. After 21 days, the ORGs were evaluated histologically, and the irritant and corrosion potential was determined by means of viability measurements (MTT assay) and cytokine release, according to 431 and 439 OECD tests guidelines. Skin models showed similar histological characteristics to native skin and were able to classify different substances with high accuracy, showing their applicability to skin irritation and corrosion tests. Although cytokines release seems to be chemical-dependent, a tendency was observed, leading to the improvement of the prediction capacity. Nevertheless, further studies should be done to reduce variability in order to increase prediction capacity.

Carácterísticas histológicas de piel cultivada in vitro / Histological Characteristics Of Skin Culture In Vitro

Los injertos de piel cultivados in vitro han sido utilizados tanto en la regeneración de tejidos de áreas cruentas de la piel (úlceras crónicas y quemaduras de diversos grados), como para el tratamiento de genodermatosis. En nuestro medio existe un alto índice de pacientes con úlceras crónicas y un total de 2319 pacientes quemados, en un período de 10 años. El tratamiento convencional de estos pacientes genera estadías de hospitalización prolongadas y costos hospitalarios muy elevados. En este trabajo se establecieron las condiciones para el cultivo y expansión de queratinocitos y fibroblastos humanos, con el propósito de generar un equivalente cutáneo. A su vez, se evaluaron sus características histológicas con el objeto de ofrecer otras opciones de tratamiento. Las células se obtuvieron a partir de piel proveniente de donantes de órganos y de sobrantes de procedimientos quirúrgicos. Se logró un mayor éxito en la obtención de cultivos primarios, con muestras provenientes de donantes menores de 40 años (65%), comparado con los obtenidos de mayores (33%). En el equivalente cutáneo producido con estas células se demostró que los queratinocitos y los fibroblastos, presentan características funcionales, estructurales y morfológicas semejantes a la piel intacta. El equivalente cutáneo además de conservar las características funcionales y estructurales de la piel intacta, presenta otras ventajas en términos de costos, manipulación y estabilidad frente a otros productos similares importados.

In vitro skin culture have been used in the regeneration of skin wound (chronic ulcers and burns), and for genodermatosis treatment. In our country there is a high patient number with chronic ulcers and 2319 burned in a period of 10 years. Conventional treatment generates long hospitalization stays and high costs. We established culture conditions of keratinocytes and fibroblasts expansion, to generate a cutaneous substitute in order to offer other treatment options. Skin cells were obtained from organs donors and surgical surpluses procedures. Major success was achieved in primary cultures obtained from 40-year-old younger donors samples (65%), compared with older donors (33%). In one cutaneous substitute produced with these cells, was demonstrated that keratinocytes and fibroblasts, presented functional, structural and morphologic characteristics similar to normal skin. Cutaneous substitute besides preserve normal skin functional and structural characteristic, compared with other similar imported products, our cutaneous substitute, showed many advantages in terms of costs, manipulation and stability.

Human skin keratinocytes modified by a Friend-derived retroviral vector: a functional approach.

The goal of this study was to test the efficiency and possible functional effects of a Friend Leukemia derived retrovirus vector (FOCH29-NeoR) on cultured human keratinocytes, obtained from skin biopsy samples. The keratinocytes were grown and infected with filtered Friend vector supernatant. After one or two doses of infection, one duplicate of the culture was submitted to selection with G418; the other one was utilized for DNA extraction and PCR modification detection. Transduction efficiency was 46.66 percent and 47.22 percent for one and two doses of infection respectively (range 100 to 15 %). Colony Forming Efficiency (CFE) assays were done with Rodhamine-B staining in nonselected modified cultures and negative controls. There was no difference in CFE (% CFE= 10.74+/-6.53 negative control vs % CFE= 9.22+/-5.45 with one dose, and % CFE= 10.03+/-5.74 with two doses of infection). Nevertheless, the cell-cycle analysis done by Propidium Iodade (PI) incorporation and colchicine-arrest assays in nonselected transduced and nontransduced cells show that transduced keratinocytes have a longer time to enter G2. As far as we know, this is the first report of retroviral transduction-induced changes in the cell cycle done on human keratinocytes. This observation is very important because retroviral vectors of genes, such as platelet derived growth factor (PDGF) or vascular endothelial growth factor (VEGF), are expected to facilitate the implementation of these modified cultures for tissue grafting and skin substitute development and potentiate the effectiveness of the grafts.

Intragraft cytokine expression in heart transplants with mild or no histological rejection.

UNLABELLED: The study of pro-inflammatory cytokines produced in situ in heart allografts may help to understand the mechanisms of rejection and open new possibilities to control graft rejection. METHODS: A total of 23 endomyocardial biopsies obtained from 16 transplanted patients treated with triple-drug therapy (azathioprine, prednisone, and cyclosporine) were studied. mRNA expression for tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 beta, IL-6, IL-10, IL-12, IL-15, transforming growth factor (TGF)-beta, and beta-actin was determined by reverse transcription polymerase chain reaction (RT-PCR) and Southern blotting. Semiquantitative analysis was done by establishing the ratio between densitometric integrated value of each cytokine with the beta-actin and correlated with the histopathologic findings. RESULTS: Three groups of biopsies were determined according to the International Society for Heart and Lung Transplantation criteria: grade 0 (control group, n=12), grade 1A (sub-clinical rejection, n=6) and 'quilty effect' (n=5). An increased expression of mRNA for TNF-alpha and IL-6 (p=0.0091 and 0.0075, respectively) was found associated with rejection grade 1A episodes, mRNA for IL-1 beta was nonspecifically expressed in all the study groups, while IL-10 mRNA was not detected in any of the biopsies studied. mRNA for IL-12 and IL-15 was not associated with rejection. Interestingly, TGF-beta was not detected in any of the biopsies with the 'quilty pattern'. CONCLUSION: The association of TNF-alpha and IL-6 mRNA in situ expression with mild histologically probed rejection episodes may be used in the monitoring of heart transplants.

Efficient transduction of hemopoietic CD34+ progenitors of human origin using an original retroviral vector derived from Fr-MuLV-FB29: in vitro assessment.

A novel retroviral vector has been designed based on a Friend-murine leukemia virus (Fr-MuLV) FB29 strain. The latter has been selected according to characteristics of pathogenicity in mice where it induces a disease of the haemopoietic system affecting all lineages. Higher infectivity has also been demonstrated as compared to other strains. In accordance with these findings, the amphotropic producer clone used in this study carrying along the neomycine resistance gene (FOCH-Neo), harbors viral titers over 10(7) cfu/ml. To investigate the potential of genetically engineering hematopoietic precursors, CD34+ progenitors were selected from cord blood, bone marrow, and peripheral blood mobilized stem cells (patients + solid tumors) and transduced with FOCH-Neo. High transduction rates were achieved using virus supernatant and minimal doses of hematopoietic growth factors during pretransduction and transduction steps. A polymerase chain reaction (PCR) assay investigating the presence of both neomycin-encoding and viral vector sequences tested positive in 45-90% of granulocyte-macrophage colony-forming units (CFU-GM) generating cells (bone marrow and peripheral blood derived cells) following transduction. An average of 35% colonies showed resistance to G418. Such levels of transduction proved reproducible using only supernatants harboring over 10(7) cfu/ml. In those experiments where long-term in vitro cultures could be maintained over 5 weeks (all cord blood and 5 among 23 PBSC), efficient transduction of long-term culture initiating cell (LTC-IC) hematopoietic progenitors was demonstrated on the basis of both resistance to G418 and virus integration. In the latter case, the PCR assay tested positive in as much as 35-60% of late unselected CFU-colonies. This novel retroviral vector harbors interesting features toward genetic modification of hematopoietic progenitors.

Natural killer cell activity in patients with pulmonary tuberculosis and in healthy controls.

Natural killer (NK) cell activity of freshly isolated peripheral blood mononuclear cells (MNC) or cells stimulated for 72 h with 10 micrograms/ml of a sonicate antigen of Mycobacterium tuberculosis H37Rv were studied in healthy responder and non-responder controls, as detected by lymphocyte proliferation with specific antigen, and in patients with pulmonary tuberculosis. K-652 cells were used as targets in a 4 h 51Cr release assay. MNC from patients exhibited a significant decrease in NK function as compared with responder controls (p less than 0.02). NK activity in responder individuals was highest 72 h after incubation with antigen. Non-stimulated cells were not cytotoxic. MNC from healthy responder and non-responder subjects incubated for 72 h with antigen yielded a significant increase in the percentage NK cytotoxicity at all effector/target ratios studied (p less than 0.01) as well as in the number of lytic units per culture (p less than 0.004). However, this increase was higher in responder individuals as compared to non-responder subjects (p = 0.02). The response to antigen was not significant in the group of patients although a net increase was also observed in the whole group. Only 4 of 9 patients exhibited significant increased responses after antigenic stimulation, 3 showed moderate responses, 1 did not respond and in a further patient a decrease was observed. The decreased NK activity could be secondary to abnormalities in the production of lymphokines by tuberculous patients. Although the role of non-specific cytotoxic cells in tuberculosis is unknown, their alterations could contribute to the pathogenesis of the disease.