Gliosis induction on locus coeruleus in a living liver donor experimental model: A brief review.

Living Donor Liver Transplantation (LDLT) is a promising approach to treating end-stage liver diseases, however, some post-operatory complications such as pneumonia, bacteremia, urinary tract infections, and hepatic dysfunction have been reported. In murine models using partial hepatectomy (PHx), a model that emulates LDLT, it has been determined that the synthesis of hepatic cell proliferation factors that are associated with noradrenaline synthesis are produced in locus coeruleus (LC). In addition, studies have shown that PHx decreases GABA and 5-HT2A receptors, promotes loss of dendritic spines, and favors microgliosis in rat hippocampus. The GABA and serotonin-altered circuits suggest that catecholaminergic neurons such as dopamine and noradrenaline neurons, which are highly susceptible to cellular stress, can also be damaged. To understand post-transplant affections and to perform well-controlled studies it is necessary to know the potential causes that explain as a liver surgical procedure can produce brain damage. In this paper, we review several cellular processes that could induce gliosis in LC after rat PHx.

BrdU does not induce hepatocellular damage in experimental Wistar rats.

Bromodeoxyuridine (BrdU) is used in studies related to cell proliferation and neurogenesis. The multiple intraperitoneal injections of this molecule could favor liver function profile changes. In this study, we evaluate the systemic and hepatocellular impact of BrdU in male adult Wistar rats in 30 %-partial hepatectomy (PHx) model. The rats received BrdU 50 mg/Kg by intraperitoneal injection at 0.5, 1, 2, 3, 6, 9 and 16 days after 30 %-PH. The rats were distributed into four groups as follows, control, sham, PHx/BrdU(-) and PHx/BrdU(+). On day 16, we evaluated hepatocellular nuclei and analyzed histopathological features by haematoxylin-eosin stain and apoptotic profile was qualified by caspase-3 presence. The systemic effect was evaluated by liver markers such as alanine transferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), alkaline phosphatase (AP), bilirubin, total proteins and serum albumin content. The statistical analysis consisted of a student t-test and one-way ANOVA. BrdU did not induce apoptosis or hepatocellular damage in male rats. Multiple administrations of BrdU in male rats did not induce significant decrease body weight, but increased serum ALT and LDH levels were found. Our results show that the BrdU does not produce hepatocellular damage.

Enhanced antitumor activity induced by a DNA vaccine encoding E7 antigen fused to an ERAD-targeting sequence.

The endoplasmic reticulum (ER) is a key organelle in cell homeostasis and cell health through antigen presentation to immune cells. Thus, the ER has become a therapeutic target to induce cellular immune responses. We previously reported the antitumor effect of a DNA vaccine that expresses the E7 antigen fused to the cyclooxygenase-2 (COX-2) protein. This inflammation-related enzyme contains a degradation cassette associated with the endoplasmic reticulum-associated degradation (ERAD) pathway. To avoid the use of full-length COX-2 and any risk of adverse effects due to the activity of its catalytic site, we designed new versions of the fusion protein. These new constructs encode the E7 antigen fused to the signal peptide and the ERAD sequence of COX-2 with or without the membrane-binding domain (MBD) as well as deletion of the catalytic site. We evaluated the antigen-specific antitumor effect of these DNA constructs in murine prophylactic and therapeutic cancer models. These assays showed that the ERAD cassette is the minimum sequence in the COX-2 protein that induces an antitumor effect when fused to the E7 antigen with the advantage of eliminating any potential adverse effects from the use of full-length COX-2.

Plasmid DNA for Therapeutic Applications in Cancer.

Recently, the interest in using nucleic acids for therapeutic applications has been increasing. DNA molecules can be manipulated to express a gene of interest for gene therapy applications or vaccine development. Plasmid DNA can be developed to treat different diseases, such as infections and cancer. In most cancers, the immune system is limited or suppressed, allowing cancer cells to grow. DNA vaccination has demonstrated its capacity to stimulate the immune system to fight against cancer cells. Furthermore, plasmids for cancer gene therapy can direct the expression of proteins with different functions, such as enzymes, toxins, and cytotoxic or proapoptotic proteins, to directly kill cancer cells. The progress and promising results reported in animal models in recent years have led to interesting clinical results. These DNA strategies are expected to be approved for cancer treatment in the near future. This review discusses the main strategies, challenges, and future perspectives of using plasmid DNA for cancer treatment.

Targeting E7 antigen to the endoplasmic reticulum degradation pathway promotes a potent therapeutic antitumor effect.

It has been previously reported that targeting and retaining antigens in the endoplasmic reticulum (ER) can induce an ER stress response. In this study, we evaluated the antitumor effect of E7 antigen fused to an ERresident protein, cyclooxygenase-2, which possesses a 19-aminoacid cassette that directs it to the endoplasmic reticulum-associated protein degradation (ERAD) pathway. The featured DNA constructs, COX2-E7 and COX2-E7ΔERAD, with a deletion in the 19-aminoacid cassette, were used to evaluate the importance of this sequence. In vitro analysis of protein expression and ER localisation were verified. We observed that both constructs induced an ER stress response. This finding correlated with the antitumor effect in mice injected with TC-1 cells and treated with different DNA constructs by biolistic vaccination. Immunisation with COX2-E7 and COX2-E7ΔERAD DNA constructs induced a significant antitumor effect in mice, without a significant difference between them, although the COX2-E7 construct induced a significant E7-specific immune response. These results demonstrate that targeting the E7 antigen to the ERAD pathway promotes a potent therapeutic antitumor effect. This strategy could be useful for the design of other antigen-specific therapies.

Caspase-3-related apoptosis prevents pathological regeneration in a living liver donor rat model.

PURPOSE: The main goal of this study was to determine the relationship of cleaved-caspase-3 (C3)-related apoptosis and hepatic proliferation, during the liver repopulation in a living liver donor rat model. MATERIAL/METHODS: Thirty-three animals were randomized into eleven groups and evaluated on postoperative from 3 â€‹h until 384 â€‹h after 30%-partial hepatectomy (30%-PHx). Liver sections (5 â€‹µm) were processed by hematoxylin-eosin, and immunostaining for C3, accompanied by hepatic function test. C3 content and the hepatic lobule enlargement were analyzed by optical density, followed by cell counting. RESULTS: Transient variations of alanine transferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were found. Significant increase in the C3 levels, and cell nuclei number, were detected at 12 â€‹h and 48 â€‹h after 30%-PHx, evidencing a correlation of p â€‹= â€‹-0.3679. CONCLUSION: In the 30%-PHx rat model, C3-related apoptosis prevents proliferative pathological conditions during the hepatic lobule re-modeling.

Asn194Lys mutation in RVG29 peptide increases GFP transgene delivery by endocytosis to neuroblastoma and astrocyte cells.

OBJECTIVES: A cell-penetrating peptide-based delivery system could target specific types of cells for therapeutic genes delivery. To increase the gene delivery efficiency into neuronal phenotype cells, we introduced an Asn194Lys mutation to RVG29 peptide derived from rabies virus glycoprotein and added a nuclear localization signal to enhance its nuclear import. METHODS: Mutant RVG or wild-type RVG peptide, a karyophilic peptide (KP) and a plasmid encoding green fluorescent protein (pGL) were bound by electrostatic charges to form four different kinds of RVG complexes. Immunofluorescence was used to assess the gene transfection efficiency into astrocytes, oligodendrocyte precursor cells (OPCs), SH-SY5Y, HeLa and NIH/3T3 cells. The cellular uptake mechanism of RVG29 complexes was examined using endocytosis inhibitors. KEY FINDINGS: The mRVG29 peptide has the ability to enhance the nuclear import of plasmids. The Asn194Lys mutation in RVG29 peptide of the pGL-mRVG29 complex and the addition of KP to the pGL-RVG29-KP complex increased the capacity to deliver DNA by endocytosis in astrocytes and SH-SY5Y cells. CONCLUSIONS: The complexes pGL-mRVG29 and pGL-RVG29-KP have specificity for transfecting astrocytes and SH-SY5Y cells. The karyophilic capacity of this new mRVG peptide render it promising candidate to act as gene delivery vector into the brain cells.

Estrés oxidativo y capacidad antioxidante en deportistas con dieta rica en antioxidantes con zarzamora (Rubus sp) / Estresse oxidativo e capacidade antioxidante nos atletas com dieta rica em antioxidantes com amora-preta (Rubus sp) / Oxidative stress in athletes with antioxidant-rich diet of blackberry (Rubus sp)

Objetivo. Identificar el comportamiento del Estrés Oxidativo (EO) en atletas con y sin la ingesta de dieta rica en antioxidantes durante el periodo competitivo. Métodos. Se evaluaron a 14 atletas de alto rendimiento del equipo de balonmano, quienes fueron distribuidos 7 en un grupo experimental y 7 en un grupo control (con y sin ingesta de zarzamora, respectivamente). El consumo de la bebida de zarzamora o placebo para ambos grupos, fue de una dosis diaria durante 15 días (7 días en la etapa de pre competencia, 7 días durante el periodo de competencia y una dosis 24h después de finalizar la competencia). Se cuantificó el EO (i.e. prueba d-ROMs, unidades Cornelli, U. Cor.) y la capacidad total antioxidante (CTA) en plasma (i.e. prueba PAT, unidades Carratelli, U. Carr.), en 4 momentos: (1) reposo (1 semana previa a competencia, antes del suministro de bebida); (2) pre competencia (una semana antes de la competencia); (3) al final de competencia y (4) a las 24 h después de la competencia. Resultados. En el grupo experimental, el EO disminuyó de manera significativa (p = .018) al comparar la toma en reposo con la toma previa a la competencia después de 7 días de la ingesta de la dieta rica en antioxidantes. El grupo control presentó aumentos significativos de la CTA en la toma previa a competencia (p = .028) así como al final de la misma (p = .046), con respecto a la toma en reposo. Conclusión. El EO se incrementa después de la competencia y estimula la CTA. La ingesta de la dieta rica en antioxidantes es favorable en el entrenamiento previo a la competencia ya que promueve la regulación del EO, disminuyendo los valores del mismo (AU)

Objective. Identify Oxidative Stress (OS) behavior in athletes with and without the intake of an antioxidant-rich diet during a competitive period. Methods.14 high-performance athletes of handball team were evaluated. Two groups were established: 7 in an experimental group (blackberry intake) and 7 in a control group (with and without the intake of blackberry, respectively). The intake of blackberry beverage or placebo for both groups was a daily dose for 15 days (7 days in the pre-competition stage, 7 days during the competition period and a dose 24h after the end of the competition). OS (i.e. d-ROMs test, Cornelli units, U.Cor.) and the Total Antioxidant Capacity (TAC) (i.e. PAT test, Carratelli units, U. Carr.) on plasma, were quantified at 4 moments: (1) resting (1 week before the competition, before the beverage intake); (2) pre-competition (one week before the competition); (3) at the end of the competition; and (4) 24 hours after the competition. Results. On the experimental group, OS was significantly reduced (p =.018) comparing resting takes with the pre-competition, after 7 days of the antioxidant-rich diet. The control group had a significant rise on TAC presented in precompetition (p =.028) as well as at end of competition (p =.046) compared to the resting take. Conclusion. The OS rises after competition and stimulates the TAC. The intake of an antioxidant-rich diet is helpful on pre-competition training since it promotes the regulation of OS, diminishing its levels (AU)

Objetivo. Identificar o comportamento do estresse oxidativo (EO) em atletas com e sem a ingestão de dieta rica em antioxidantes durante o período competitivo. Métodos. Foram avaliadas 14 atletas de alto rendimento da equipe de handebol, que foram distribuídos em 7 num grupo experimental e 7 num grupo de controlo (com e sem ingestão de amora, respectivamente). O consumo da amora bebida ou placebo em ambos os grupos era uma dose diária durante 15 dias (7 dias no pré competição, 7 dias durante a competição e uma dose 24 horas depois de terminar a competição). O EO foi quantificado (i.e. prova d-ROMs, unidades Cornelli, U. Cor.) e a capacidade antioxidante total (CAT) no plasma (isto é, teste de PAT, unidades Carratelli, U. Carr.) em 4 fases: (1) repouso (uma semana antes da competição antes do fornecimento de bebida); (2) pré-competição (uma semana antes da competição); (3) no fim da competição e (4) às 24 h após a competição. Resultados. No grupo experimental, o EO diminuiu significativamente (p = 0,018) comparando a toma em repouso com a toma anterior à competição após 7 dias de ingestão da dieta rica em antioxidantes. O grupo de controlo teve aumentos significativos no CAT na toma previa à competição (p = .028) e no final da mesma (p = .046), com respeito à toma em repouso. Conclusão. O EO aumenta após da competição e estimula o CAT. A ingestão de dieta rica em antioxidantes é favorável no treinamento pré-competição, uma vez que promove a regulação da EO, diminuindo os valores do mesmo (AU)