Prolidase enzyme is required for extracellular matrix integrity and impacts on postnatal cerebellar cortex development.

The extracellular matrix is essential for brain development, lamination, and synaptogenesis. In particular, the basement membrane below the pial meninx (pBM) is required for correct cortical development. The last step in the catabolism of the most abundant protein in pBM, collagen Type IV, requires prolidase, an exopeptidase cleaving the imidodipeptides containing pro or hyp at the C-terminal end. Mutations impairing prolidase activity lead in humans to the rare disease prolidase deficiency characterized by severe skin ulcers and mental impairment. Thus, the dark-like (dal) mouse, in which the prolidase is knocked-out, was used to investigate whether the deficiency of prolidase affects the neuronal maturation during development of a brain cortex area. Focusing on the cerebellar cortex, thinner collagen fibers and disorganized pBM were found. Aberrant cortical granule cell proliferation and migration occurred, associated to defects in brain lamination, and in particular in maturation of Purkinje neurons and formation of synaptic contacts. This study deeply elucidates a link between prolidase activity and neuronal maturation shedding new light on the molecular basis of functional aspects in the prolidase deficiency.

Long-term effects after treatment with platinum compounds, cisplatin and [Pt(O,O'-acac)(γ-acac)(DMS)]: Autophagy activation in rat B50 neuroblastoma cells.

Cisplatin (cisPt), among the best known components of multi-drug front-line therapies used for the treatments of solid tumors, such as the childhood neuroblastoma, acts through DNA linking. Nevertheless, the cisPt effectiveness is compromised by the onset of severe side effects, including neurotoxicity that results in neurodegeneration, cell death, and drug-resistance. In the field of experimental oncology, aimed at overcoming cytotoxicity and chemoresistance, great efforts are devoted to the synthesis of new platinum-based drugs, such as [Pt(O,O'-acac)(γ-acac)(DMS)] (PtAcacDMS), which shows a specific reactivity with sulfur residues of enzymes involved in apoptosis. Autophagy, an evolutionary conserved degradation pathway for recycling of cytoplasmic components, represents one of the mechanisms adopted by cancer cells which contribute to drug-resistance. In the present study, standard acute (48 h-exposure) and long-term effects (7 day-recovery after treatment or 7 day-recovery followed by reseeding and 96 h-growth), of cisPt and PtAcacDMS (40 and 10 µM, respectively) were investigated in vitro employing rat B50 neuroblastoma as a cancer model. Using fluorescence and electron microscopy, as well as biochemical techniques, our data highlight a key role of the autophagic process in B50 cells. Specifically, long-term effects caused by cisPt lead to inhibition of the apoptotic process and paralleled by the activation of autophagy, thus evidencing that autophagy has a protective role after cisPt exposure, allowing cells to survive. Whereas, long-term effects produced by PtAcacDMS lead toward both apoptosis and autophagy activation. In conclusion, autophagy may represents an alternative cell death pathway, circumventing drug-resistance strategies employed by cancer cells to survive chemoterapy.

Resveratrol-procyanidin blend: nutraceutical and antiaging efficacy evaluated in a placebocontrolled, double-blind study.

BACKGROUND: Skin is constantly exposed to pro-oxidant environmental stress from several sources, including air pollutants, ultraviolet solar light, and chemical oxidants. Reactive oxygen species have been implicated in age-related skin disorders. Dietary bioactive antioxidant compounds, such as polyphenols, have beneficial effects on skin health. The advantage of a nutritional administration route is that blood delivers nutraceutical bioactive compounds continuously to all skin compartments, ie, the epidermis, dermis, and subcutaneous fat. The purpose of this study was to evaluate the topical and systemic effects of a dietary supplement containing resveratrol and procyanidin on age-related alterations to the skin, the skin antioxidant pool, and systemic oxidative stress levels. METHODS: An instrumental study was performed in 50 subjects (25 treated with supplements and 25 with placebo) to identify clinical features induced by chronoaging or photoaging. Product efficacy was evaluated after 60 days of treatment in terms of in vivo and in situ skin hydration, elasticity, and skin roughness levels, systemic oxidative stress levels by plasmatic derivatives of reactive oxygen metabolites and oxyadsorbent tests, and extent of the skin antioxidant pool. RESULTS: After 60 days of treatment, values for systemic oxidative stress, plasmatic antioxidant capacity, and skin antioxidant power had increased significantly. Additionally, skin moisturization and elasticity had improved, while skin roughness and depth of wrinkles had diminished. Intensity of age spots had significantly decreased, as evidenced by improvement in the individual typological angle. CONCLUSION: Nutraceutical and pharmacological intervention with a supplement characterized by a specific blend of resveratrol and procyanidin may be a promising strategy to support treatments for the reduction of skin wrinkling, as well as reducing systemic and skin oxidative stress.

Cisplatin induces changes in the matrix metalloproteinases and their inhibitors in the developing rat cerebellum.

The role of matrix metalloproteinases (MMP-3 and MMP-9), tissue inhibitor of MMP (TIMP-2), and GAP-43 (growth-associated-protein) in neocerebellar vermis lobules during postnatal histogenesis was studied after challenge with cisplatin (cisPt). CisPt is one of the most effective and widely used cytotoxic agents in the treatment of a variety of malignancies, in both children and adult patients. A single injection of cisPt to 10-day-old rats altered the spatiotemporal MMP/TIMP expression balance and provoked a decrease in GAP43 immunoreactivity. The imbalance appeared one day (PD11) after cisPt injection, producing disorder of cerebellum histogenesis processes in which MMPs might be involved, i.e. genesis of granule cells, Purkinje cell differentiation and synaptogenesis. Following the early injury, a simultaneous increase in MMP and TIMP expression in the ML was noticed at PD17, likely initiating recovery of Purkinje cell dendrite growth and remodelling processes. However, disturbances at the beginning of recovery phase had emerged, probably due to the down-regulation of GAP-43 after cisPt treatment. The data provide further support for the usefulness of cisPt as a tool for the study of morphological and functional changes in the CNS during postnatal development.

The developmental neurotoxicity study of platinum compounds. Effects of cisplatin versus a novel Pt(II) complex on rat cerebellum.

In the field of experimental oncology, many efforts are being carried out to search new platinum-based drugs overcoming the CNS toxicity and drug resistance. One of the adopted strategies is the synthesis of platinum compounds able to form Pt-DNA adducts different from the cisplatin ones or to react with other subcellular targets. In this context a novel Pt(II) complex, [Pt(O,O'-acac)(γ-acac)(DMS)](PtAcacDMS), was synthesized which reacts preferentially with protein thiols or thioethers. In this work we investigated the in vivo effects of cisplatin and PtAcacDMS on normal development. Moreover, to verify the dose-dependence of the effects, different groups of animals were treated with 5 µg/g or 10 µg/g body weight of cisPt and PtAcacDMS. We have focused our attention on the cerebellum because it provides a useful model system to evaluate the outcomes of perinatal treatment with chemotherapeutic agents on key CNS developmental processes such as neural cells proliferation, migration and differentiation. We have demonstrated the ability of both cisPt and PtAcacDMS to reach the brain tissue once injected. The brain platinum content after PtAcacDMS treatment was notably higher (approximately 4-fold as much) than after cisPt. The platinum accumulation in the brain was still considerable 7 days after PtAcacDMS administration. However, compared with cisplatin, PtAcacDMS induces less severe changes on fundamental events of neuroarchitecture development, such as no high apoptotic events, less altered granule cell migration and Purkinje cell dendrite growth, suggesting a low neurotoxicity of this new Pt complex for normal CNS. The mild damages could be attributable to the different subcellular target of this compound as well as to a greater efficiency of the cell repair system to recognize the drug-target adducts and to repair them. Together with the previously demonstrated antineoplastic effectiveness in vitro, the findings here reported suggest PtAcacDMS as a potential alternative to cisplatin indicating, at the same time, that the choice of platinum compounds with new subcellular targets could be a strategy to prevent neurotoxicity induced by cisplatin and overcome drug resistance induced by mutations in the intrinsic apoptotic pathway.