Preclinical toxicological assessment of a novel monoclonal antibody targeting human platelet-derived growth factor CC (PDGF-CC) in PDGF-CChum mice.

Platelet-derived growth factor CC (PDGF-CC) is important during foetal development but also in pathogenesis of neurologic diseases, cancer and fibrosis. We have previously demonstrated that blocking the PDGF-CC/PDGF receptor alpha (PDGFRα) axis resulted in reduction of stroke volume and cerebrovascular permeability after experimentally induced stroke. Recently, we could translate these findings into the clinic showing that imatinib, a small tyrosine kinase inhibitor targeting PDGF receptors, can significantly improve neurological outcome after ischemic stroke in human. Herein we report preclinical toxicological analyses of our newly generated monoclonal anti-human PDGF-CC antibody 6B3 (mAb 6B3) in PDGF-CC humanized mice. Beside histological organ assessment, we also analysed serum, urine, haematological parameters and the general health status of the treated mice. We could not find any indications that mAb 6B3 is toxic or has other significant side effects neither in short, nor in long treatment regimens. Our results indicate that mAb 6B3 can be further developed for clinical use. This opens up the possibility to assess the therapeutic potential of blocking PDGF-CC in diverse pathological conditions such as neurologic diseases, cancer and fibrosis.

Foot reflexology in feet impairment of people with type 2 diabetes mellitus: randomized trial / Reflexologia podal no comprometimento dos pés de pessoas com diabetes mellitus tipo 2: ensaio randomizado / Reflexología podal en el comprometimiento de los pies de personas con diabetes mellitus tipo 2: ensayo aleatorio

AbstractObjective: to evaluate the effect of foot reflexology on feet impairment of people with type 2 diabetes mellitus.Method: this is a randomized, controlled and blind clinical trial. The sample was comprised by people with type 2 diabetes mellitus who, after being randomized into Treated group (n = 21) and Control group (n = 24), received guidelines on foot self-care. To the Treated Group it was also provided 12 sessions of foot reflexology. The scores of impairment indicators related to skin and hair, blood circulation, tissue sensitivity and temperature were measured by means of the instrument for assessing tissue integrity of the feet of people with diabetes mellitus. Chi-square test, Fisher exact test, Mann-Whitney test and regression analyzes were applied to the data, considering a significance level of 5% (P value <0.05).Results: participants who received the therapy showed better scores in some impairment indicators related to skin and hair (hair growth, elasticity/turgor, hydration, perspiration, texture and integrity of the skin/ skin peeling).Conclusion: the foot reflexology had a beneficial effect on feet impairment of people with type 2 diabetes mellitus, which makes it a viable therapy, deserving investment. This study was registered in the Brazilian Registry of Clinical Trials - RBR-8zk8sz.

ResumoObjetivo:avaliar o efeito da reflexologia podal no comprometimento dos pés de pessoas com diabetes mellitus tipo 2.Método:trata-se de um ensaio clínico, randomizado, controlado e mascarado. A amostra foi composta por pessoas com diabetes mellitus tipo 2 que, após serem randomizadas em grupo Tratado (n=21) e Controle (n=24), receberam orientações de autocuidado com os pés. Ao Grupo Tratado também foram fornecidas 12 sessões de reflexologia podal. Foram mensurados os escores de comprometimento de indicadores relacionados à pele e pelos, circulação sanguínea, sensibilidade e temperatura tissular por meio do Instrumento para avaliação da integridade tissular dos pés de pessoas com diabetes mellitus. Aos dados foram aplicados os testes Qui-Quadrado, Exato de Fisher, Mann-Whitney e Análises de regressão, considerando-se nível de significância de 5% (Valor P<0,05).Resultados:os participantes que receberam a terapia apresentaram melhores escores de comprometimento em alguns indicadores relacionados à pele e pelos (crescimento de pelos, elasticidade/tugor, hidratação, transpiração, textura e integridade da pele/descamação cutânea).Conclusão:a reflexologia podal apresentou efeito benéfico sobre o comprometimento dos pés de pessoas com diabetes mellitus tipo 2, o que a torna uma terapia viável e que merece investimento. Este estudo foi registrado no Registro Brasileiro de Ensaios Clínicos - RBR-8zk8sz.

ResumenObjetivo:evaluar el efecto de la reflexología podal en el comprometimiento de los pies de personas con diabetes mellitus tipo 2.Método:se trata de un ensayo clínico, aleatorio, controlado y enmascarado. La muestra estuvo compuesta por personas con diabetes mellitus tipo 2 que, después de ser tratadas aleatoriamente en los grupos Tratado (n=21) y Control (n=24), recibieron orientaciones de autocuidado de los pies. También, al Grupo Tratado se le suministraron 12 sesiones de reflexología podal. Fueron medidos los puntajes de comprometimiento de indicadores relacionados a la piel y pelos, circulación sanguínea, sensibilidad y temperatura tisular por medio de instrumento para evaluación de la integridad del tejido de los pies de personas con diabetes mellitus. Los datos fueron sometidos a las pruebas Chi-cuadrado, Exacta de Fisher, Mann-Whitney y Análisis de regresión, considerando un nivel de significación de 5% (Valor p<0,05).Resultados:los participantes que recibieron la terapia presentaron mejores puntajes de comprometimiento en algunos indicadores relacionados a la piel y pelos (crecimiento de pelos, elasticidad/turgencia, hidratación, transpiración, textura e integridad de la piel/descamación cutánea).Conclusión:la reflexología podal presentó efecto benéfico sobre el comprometimiento de los pies de personas con diabetes mellitus tipo 2, lo que la torna una terapia viable y que merece inversiones. Este estudio fue registrado en el Registro Brasileño de Ensayos Clínicos - RBR-8zk8sz.

Targeting of plasminogen activator inhibitor 1 improves fibrinolytic therapy for tetracycline-induced pleural injury in rabbits.

Endogenous active plasminogen activator inhibitor 1 (PAI-1) was targeted in vivo with monoclonal antibodies (mAbs) that redirect its reaction with proteinases to the substrate branch. mAbs were used as an adjunct to prourokinase (single-chain [sc] urokinase [uPA]) intrapleural fibrinolytic therapy (IPFT) of tetracycline-induced pleural injury in rabbits. Outcomes of scuPA IPFT (0.25 or 0.0625 mg/kg) with 0.5 mg/kg of mouse IgG or mAbs (MA-33H1F7 and MA-8H9D4) were assessed at 24 hours. Pleural fluid (PF) was collected at 0, 10, 20, and 40 minutes and 24 hours after IPFT and analyzed for plasminogen activating (PA), uPA, fibrinolytic activities, levels of total plasmin/plasminogen, α-macroglobulin (αM), mAbs/IgG antigens, free active uPA, and αM/uPA complexes. Anti-PAI-1 mAbs, but not mouse IgG, delivered with an eightfold reduction in the minimal effective dose of scuPA (from 0.5 to 0.0625 mg/kg), improved the outcome of IPFT (P < 0.05). mAbs and IgG were detectable in PFs at 24 hours. Compared with identical doses of scuPA alone or with IgG, treatment with scuPA and anti-PAI-1 mAbs generated higher PF uPA amidolytic and PA activities, faster formation of αM/uPA complexes, and slower uPA inactivation. However, PAI-1 targeting did not significantly affect intrapleural fibrinolytic activity or levels of total plasmin/plasminogen and αM antigens. Targeting PAI-1 did not induce bleeding, and rendered otherwise ineffective doses of scuPA able to improve outcomes in tetracycline-induced pleural injury. PAI-1-neutralizing mAbs improved IPFT by increasing the durability of intrapleural PA activity. These results suggest a novel, well-tolerated IPFT strategy that is tractable for clinical development.

Human B-cell cancer cell lines as a preclinical model for studies of drug effect in diffuse large B-cell lymphoma and multiple myeloma.

Drug resistance in cancer refers to recurrent or primary refractory disease following drug therapy. At the cellular level, it is a consequence of molecular functions that ultimately enable the cell to resist cell death-one of the classical hallmarks of cancer. Thus, drug resistance is a fundamental aspect of the cancer cell phenotype, in parallel with sustained proliferation, immortality, angiogenesis, invasion, and metastasis. Here we present a preclinical model of human B-cell cancer cell lines used to identify genes involved in specific drug resistance. This process includes a standardized technical setup for specific drug screening, analysis of global gene expression, and the statistical considerations required to develop resistance gene signatures. The state of the art is illustrated by the first-step classical drug screen (including the CD20 antibody rituximab, the DNA intercalating topoisomerase II inhibitor doxorubicin, the mitotic inhibitor vincristine, and the alkylating agents cyclophosphamide and melphalan) along with the generation of gene lists predicting the chemotherapeutic outcome as validated retrospectively in clinical trial datasets. This B-cell lineage-specific preclinical model will allow us to initiate a range of laboratory studies, with focus on specific gene functions involved in molecular resistance mechanisms.

[Biological therapy in idiopathic inflammatory myopathies]. / Biológiai terápia idiopathiás inflammatorikus myopathiákban.

Idiopathic inflammatory myopathies are systemic, immune-mediated diseases characterized by proximal, symmetrical, progressive muscle weakness. The aim of this work is to give an overview of the biological therapy used in the treatment of idiopathic inflammatory myopathies. The authors also focus on novel results in the therapy directed against the B- and T-cells. They emphasize the importance of new trials in these diseases which may lead to the introduction of novel therapeutic options in these disorders.

Silencing of human phosphatidylethanolamine-binding protein 4 enhances rituximab-induced death and chemosensitization in B-cell lymphoma.

Rituximab is the first line drug to treat non Hodgkin's lymphoma (B-NHL) alone or in combination with chemotherapy. However, 30-40% of B-NHL patients are unresponsive to rituximab or resistant after therapy. Human phosphatidylethanolamine-binding protein 4 (hPEBP4) is a novel member of PEBP family and functions as an anti-apoptotic molecule. In this study, we found hPEBP4 to be expressed in up to 90% of B-cell lymphoma patients, but in only 16.7% of normal lymph nodes. Interestingly, hPEBP4 overexpression inhibited rituximab-mediated complement dependent cytotoxicity (R-CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC) in B-NHL cells while downregulation of hPEBP4 augmented the therapeutic efficacy of rituximab both in vitro and in vivo. Furthermore, hPEBP4 silencing sensitized the primary B-acute lymphocytic leukemia (B-ALL) cells to R-CDC. During rituximab-mediated complement dependent cytotoxicity, hPEBP4 was recruited to the cell membrane in a PE-binding domain dependent manner and inhibited R-CDC induced calcium flux and reactive oxygen species (ROS) generation. These events contributed to the decrease of cell death induced by R-CDC in B-cell lymphomas. Meanwhile, hPEBP4 knockdown potentiated the chemosensitization of the rituximab in B-cell lymphoma cells by regulating the expression of Bcl-xl, Cycline E, p21(waf/cip1) and p53 and the activation of caspase-3 and caspase-9. Considering that hPEBP4 conferred cellular resistance to rituximab treatment and was preferentially expressed in lymphoma tissue, it could be a potential valuable target for adjuvant therapy for B-cell lymphoma.

Anti-ceramide antibody prevents the radiation gastrointestinal syndrome in mice.

Radiation gastrointestinal (GI) syndrome is a major lethal toxicity that may occur after a radiation/nuclear incident. Currently, there are no prophylactic countermeasures against radiation GI syndrome lethality for first responders, military personnel, or remediation workers entering a contaminated area. The pathophysiology of this syndrome requires depletion of stem cell clonogens (SCCs) within the crypts of Lieberkühn, which are a subset of cells necessary for postinjury regeneration of gut epithelium. Recent evidence indicates that SCC depletion is not exclusively a result of DNA damage but is critically coupled to ceramide-induced endothelial cell apoptosis within the mucosal microvascular network. Here we show that ceramide generated on the surface of endothelium coalesces to form ceramide-rich platforms that transmit an apoptotic signal. Moreover, we report the generation of 2A2, an anti-ceramide monoclonal antibody that binds to ceramide to prevent platform formation on the surface of irradiated endothelial cells of the murine GI tract. Consequently, we found that 2A2 protected against endothelial apoptosis in the small intestinal lamina propria and facilitated recovery of crypt SCCs, preventing the death of mice from radiation GI syndrome after high radiation doses. As such, we suggest that 2A2 represents a prototype of a new class of anti-ceramide therapeutics and an effective countermeasure against radiation GI syndrome mortality.

Immunomodulatory effect of water extract of cinnamon on anti-CD3-induced cytokine responses and p38, JNK, ERK1/2, and STAT4 activation.

CONTEXT: Cinnamon bark is a very popular herb used in traditional medicine to treat various disorders such as chronic gastric symptoms, arthritis, and the common cold. OBJECTIVE: The immunomodulatory effect of water extract of cinnamon bark (CWE) on cytokine secretion and involvement of intracellular signaling molecules in activated T cells have been examined. MATERIALS AND METHODS: Mice were orally administered CWE for 7 days. Serum was obtained 90 min after intravenous injection of anti-CD3 antibody (Ab). Splenocytes were cultured with anti-CD3 Ab and CWE for cytokine expression, cell cycle, apoptotic/necrotic changes, and viability. IκBα, p38, JNK, ERK1/2, STAT4, and STAT6 were analyzed using western blotting. RESULTS: Administration of CWE decreased systemic levels of IFN-γ, but not the levels of IL-4 or IL-2. In vitro, CWE inhibited anti-CD3 Ab-stimulated IFN-γ and IL-4 at the mRNA and secreted protein levels. Despite its inhibition of IL-2 transcript, CWE enhanced IL-2 secretion. CWE treatment caused a reduction in the sub-G1 phase, accompanied by an increased ratio of apoptotic cells to necrotic cells. The increased IL-2 secretion by CWE was not mediated by its direct effect on CD4 T cells. CWE inhibited the activation of p38, JNK, ERK1/2, and STAT4, but not IκBα degradation or STAT6. DISCUSSION AND CONCLUSIONS: These observations provided evidence that CWE was able to down-regulate IFN-γ expression in activated T cells without altering IL-2 production, involving inhibition of p38, JNK, ERK1/2, and STAT4. Our results contribute to a better understanding of the immunomodulatory action of cinnamon bark for the application of inflammatory disorders.

Distinct cellular and therapeutic effects of obatoclax in rituximab-sensitive and -resistant lymphomas.

Bcl-2 proteins represent a rheostat that controls cellular viability. Obatoclax, a BH3-mimetic, has been designed to specifically target and counteract anti-apoptotic Bcl-2 proteins. We evaluated the biological effects of obatoclax on the anti-tumour activity of rituximab and chemotherapy agents. Obatoclax induced cell death of rituximab/chemotherapy-sensitive (RSCL), -resistant cell lines (RRCL) and primary tumour-cells derived from patients with B-cell lymphomas (N=39). Obatoclax also enhanced the activity of rituximab and had synergistic activity when combined with chemotherapy agents. The ability of Obatoclax to induce PARP cleavage varied between patient samples and was not observed in some RRCL. Inhibition of caspase activity did not affect obatoclax activity, suggesting the existence of caspase-independent death pathways. Autophagy was detected by LC3 conversion and/or electron microscopy in RRCL and in patient-derived tumour cells. Moreover, obatoclax activity was inhibited by Beclin-1 knockdown. In summary, obatoclax is an active Bcl-2 inhibitor that potentiates the activity of chemotherapy agents and, to a lesser degree, rituximab. Defining the molecular events triggered by obatoclax is necessary to further its clinical development and identify potential biomarkers that are predictive of response.