Effect of two different parts of CGF on post-extractive alveolar ridge preservation: a preliminary histomorphometric analysis in a Split-Mouth design.

Tooth extraction produces alveolar bone resorption and soft tissue remodelling, so identification of adequate technique for alveolar ridge preservation after tooth extraction is fundamental for all specific cases. Among the several biomaterials, CGF can represent an ideal alternative considering its and its mechanical and biological properties. In this preliminary study we compared the effectiveness of the use of two different parts of CGF (WP-White Part and BC-Buffy Coat) versus natural healing (CTR) by a split-mouth randomized clinical design. Four healthy patients who needed extraction of three teeth were selected. Post-extractive alveolar sockets were filled randomly with CGF-WP, CGF-BC or nothing for CTR. After 60 days, before implant placement, a biopsy for each alveola was obtained for quantitative histomorphometric analysis. The data obtained showed that the use of CGF-WP could achieve good regenerative results, supporting the use of this part for the preservation of the post-extractive alveolar socket.

In vitro effects of concentrated growth factors (CGF) on human SH-SY5Y neuronal cells.

OBJECTIVE: The aim of this study was to test the in vitro differentiation effects of concentrated growth factors (CGF), a platelet rich preparation, using SH-SY5Y cells, derived from human neuroblastoma. MATERIALS AND METHODS: SH-SY5Y cells were cultured in presence of CGF or retinoic acid (RA). After 72 h of treatment, different parameters were investigated: cell proliferation by an automated cell counter; cell viability by thiazolyl blue tetrazolium bromide (MTT) assay; cell differentiation markers, i.e., neuronal nuclear antigen (NeuN), synaptophysin (SYP) and ß3-tubulin, by immunocytochemistry and Western blotting techniques; release of nerve growth factor (NGF) and brain-derived growth factor (BDNF) by enzyme-linked immunosorbent assay (ELISA) and neurite outgrowth by a dedicated image software. RESULTS: In presence of CGF, the cell proliferation rate and viability decreased, as expected for differentiated SH-SY5Y cells. On the contrary, the cellular differentiation markers increased their expression together with the release of growth factors. Moreover, the neurite outgrowth was improved. CONCLUSIONS: The data suggest that CGF treatment positively affects the cell differentiation, regulating the expression of neuronal markers, the release of growth factors and the neurite length. Taken together these results seem to be promising in the development of new approaches for neural regeneration.

Steroids and growth factors in oral squamous cell carcinoma: useful source of dental-derived stem cells to develop a steroidogenic model in new clinical strategies.

OBJECTIVE: Head and neck region is involved in a high percentage of malignant lesions, and oral squamous cell carcinoma (OSCC) is undoubtedly the most frequently found, accounting for over 90% of malignant tumors. Hormone receptor overexpression, like Estrogen Receptor (ER), Progesterone Receptor (PR) and Endothelial Growth Factor Receptor (EGFR), and signaling have been related to the pathogenesis of OSCC. For metastasis of OSCC, Cancer Stem Cells (CSCs) undergo epithelial to mesenchymal transition (EMT) under the influence of growth factors, cytokines, and regulation of cadherins from the tumor's microenvironment. In this context, the stem cells may become a potential therapeutic target for OSCC through modulation of cytokines and RAS pathway, which is involved in intracell signal transduction. The objective of this study was to suggest an experimental steroidogenic model for OSCC in translational research. PATIENTS AND METHODS: Dental-derived Stem Cells (D-dSCs) have been obtained from apical papilla tissue that surrounds the developing tooth of healthy donors and cultured in vitro. The cells have been exposed to different concentrations of Estradiol (E2 - 10 nM and 40 nM) in order to verify their response. The number of cells and cell viability has been evaluated up to 96 hours of treatment. RESULTS: The results showed that cell growth was increased under estradiol treatments compared with cells maintained without estradiol. Moreover, no significant difference in cell death levels was detected among treatments. CONCLUSIONS: This work underlines as D-dSCs could represent a useful steroidogenic model for the development of the target and gene therapies in OSCC.

PPADS, a purinergic antagonist reduces Fos expression at spinal cord level in a mouse model of mononeuropathy.

Recent evidence suggest that ATP plays a role as an endogenous pain mediator generating and/or modulating pain signaling from the periphery to the spinal cord. In this study we evaluated the effects of intraperitoneal administration of P2 receptor antagonist, pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS), evaluating pain related behaviours and monitoring the expression of Fos, a marker of activated neurons, in an experimental mouse model of neuropathic pain (sciatic nerve tying). The PPADS administration decreased both tactile allodynia and thermal hyperalgesia in a time and dose dependent manner. The dose of 25 mg/kg PPADS completely reversed nociceptive hypersensitivity. Moreover, non-noxious stimulation induced an increase of Fos positive neurons in the spinal cord of animals with tying of sciatic nerve. PPADS administration partially reversed this increase. These results suggest that PPADS reduces neuronal activation at spinal cord level and that P2 receptors are involved in the retrograde signalling progress exciting sensory spinal neurons.

Role of carbon monoxide and biliverdin in renal ischemia/reperfusion injury.

Heme oxygenase (HO) isoforms catalyze the conversion of heme to carbon monoxide (CO) and biliverdin/bilirubin with a concurrent release of iron. There is strong evidence that HO activity and products play a major role in renoprotection, however the exact molecular mechanisms underlying the beneficial effects exerted by this pathway are not fully understood. This review is aimed at illustrating the possible mechanism/s by which HO is renoprotective in the context of ischemia/reperfusion. We will first analyze the effects of exogenous administration of bilirubin/biliverdin and CO and then describe their biological activities once generated endogenously following stimulation of the HO pathway by either pharmacological means or gene targeting-mediated approaches.

Mercuric chloride-induced alterations in stress protein distribution in rat kidney.

Mercuric chloride (HgCl2) induces acute renal failure associated to tubular impairment in experimental animals and humans. Stress proteins are a superfamily of proteins, comprising heat- shock proteins (HSP) and glucose-regulated proteins (GRP), enhanced or induced in the kidney in response to stress. They act as molecular chaperones that protect organelles and repair essential proteins which have been denatured during adverse conditions. The involvement of stress proteins in mercury-nephrotoxicity has not yet been well clarified. This study was undertaken to detect the tubular distribution of four stress proteins (HSP25, HSP60, GRP75, HSP72) in the rat kidney injected with HgCl2 and to quantify lysosomal and mitochondrial changes in straight proximal tubules, the main mercury target. Sprague-Dawley rats were administered i.p. with progressive sublethal doses of HgCl2 (0.25 mg/kg, 0.5 mg/kg, 1 mg/kg and 3.5 mg/kg) or saline (as controls) and sacrificed after 24 h. In dosages over 0.50 mg/kg, stress proteins increased and changed localization in a dose-dependent manner. HSP25 was focally expressed in altered proximal tubules at 1 mg/kg but in the macula densa it was at 3.5 mg/kg. HSP60 and GRP75 were intense in the nucleus and cytoplasm of proximal tubules but moderate in distal tubules. HSP72 was induced in distal tubules after low exposures but in proximal tubules it happened at the highest dose. Moreover, a significant increase in lysosomal and total mitochondria (normal and with broken cristae) area and density were progressively found after HgCl2 treatments. Stress proteins could represent sensitive biomarkers that strongly correlate with the degree of oxidative injury induced by HgCl2 in the rat proximal tubules.

Controlling the activation of the Bv8/prokineticin system reduces neuroinflammation and abolishes thermal and tactile hyperalgesia in neuropathic animals.

BACKGROUND AND PURPOSE: Chemokines are involved in neuroinflammation and contribute to chronic pain processing. The new chemokine prokineticin 2 (PROK2) and its receptors (PKR1 and PKR2 ) have a role in inflammatory pain and immunomodulation. In the present study, we investigated the involvement of PROK2 and its receptors in neuropathic pain. EXPERIMENTAL APPROACH: Effects of single, intrathecal, perineural and s.c. injections of the PKR antagonist PC1, or of 1 week s.c. treatment, on thermal hyperalgesia and tactile allodynia was evaluated in mice with chronic constriction of the sciatic nerve (CCI). Expression and localization of PROK2 and of its receptors at peripheral and central level was evaluated 10 days after CCI, following treatment for 1 week with saline or PC1. IL-1ß and IL-10 levels, along with glia activation, were evaluated. KEY RESULTS: Subcutaneous, intrathecal and perineural PC1 acutely abolished the CCI-induced hyperalgesia and allodynia. At 10 days after CCI, PROK2 and its receptor PKR2 were up-regulated in nociceptors, in Schwann cells and in activated astrocytes of the spinal cord. Therapeutic treatment with PC1 (s.c., 1 week) alleviated established thermal hyperalgesia and allodynia, reduced the injury-induced overexpression of PROK2, significantly blunted nerve injury-induced microgliosis and astrocyte activation in the spinal cord and restored the physiological levels of proinflammatory and anti-inflammatory cytokines in periphery and in spinal cord. CONCLUSION AND IMPLICATIONS: The prokineticin system contributes to pain modulation via neuron-glia interaction. Sustained inhibition of the prokineticin system, at peripheral or central levels, blocked both pain symptoms and some events underlying disease progression.

Aluminium exposure induces Alzheimer's disease-like histopathological alterations in mouse brain.

Aluminium (Al) is a neurotoxic metal and Al exposure may be a factor in the aetiology of various neurodegenerative diseases such as Alzheimer's disease (AD). The major pathohistological findings in the AD brain are the presence of neuritic plaques containing beta-amyloid (Abeta) which may interfere with neuronal communication. Moreover, it has been observed that GRP78, a stress-response protein induced by conditions that adversely affect endoplasmic reticulum (ER) function, is reduced in the brain of AD patients. In this study, we investigated the correlation between the expression of Abeta and GRP78 in the brain cortex of mice chronically treated with aluminium sulphate. Chronic exposure over 12 months to aluminium sulphate in drinking water resulted in deposition of Abeta similar to that seen in congophilic amyloid angiopathy (CAA) in humans and a reduction in neuronal expression of GRP78 similar to what has previously been observed in Alzheimer's disease. So, we hypothesise that chronic Al administration is responsible for oxidative cell damage that interferes with ER functions inducing Abeta accumulation and neurodegenerative damage.

Exposure to aluminium changes the NADPH-diaphorase/NPY pattern in the rat cerebral cortex.

Aluminium (Al) impairs the glutamate-nitric oxide-cGMP pathway and reduces the number of nitroxidergic neurons in the rat somatosensory cortex. To understand better the effect of the time of exposure, we monitored the effect of aluminium administration on nitroxidergic neurons, identified by NADPH-diaphorase (NADPH-d) or by nitric oxide synthase (NOS) staining, after 0.5, 1, 2, 3, 6 and 12 months of aluminium administration. Since neuropeptide Y (NPY) is known to be colocalised with nitric oxide synthase in cortical neurons, the aim of this work was to study the effects of Al administration on the cortical expression of NADPH-d, nNOS, and NPY. NADPH-d or NOS positive neurons were found scattered in the cortex where they constituted about 1% of all neurons. Double staining using NADPH-d and NPY showed that almost all nitroxidergic neurons were co-localised with NPY neurons (NADPH-d/NPY double stained neurons) whereas some neurons were stained only with NPY (NPY single stained neurons) ; these were more numerous than NADPH-d/NPY double stained neurons. Al significantly reduced NADPH-d and nNOS positive neurons in the cerebral cortex time dependently, with the greatest effect appearing after 3 months. Also measured was the integrated optical density (IOD) of nNOS positive neurons showing a significant decrease of NOS immunostaining even in the remaining NOS positive neurons. The double staining experiment exhibited a decrease in NADPH-d/NPY double stained neurons with an apparent increase in NPY single stained neurons; these then decreased after 6-12 months. On the whole, the results confirm that Al impairs nitroxidergic pathways time dependently; moreover, the transient increase in NPY single stained neurons from 1 to 3 months suggests that there is an intraneuronal down-regulation of NOS, without affecting neuronal viability. In addition, the decrease in the NPY system found at 6 and 12 months may indicate that Al affected nitroxidergic and NPY systems at different times.

Dose-dependent mercuric chloride tubular injury in rat kidney.

Mercuric chloride (HgCl(2)) produces an acute renal failure in experimental animal models. Since the mechanism of tubular injury has not completely been clarified, this morpho-quantitative study was undertaken to better understand the effects of 2 sublethal doses (T1=1 mg/kg and T3.5=3.5 mg/kg) of HgCl(2) in rat proximal tubules. Morphometrical analysis was performed to quantify both cytoplasmic and nuclear changes found in treated in respect to saline-injected proximal tubules. In the controls, single-cell damage was occasional and nucleolar changes were absent. HgCl(2) induced progressively severe proximal tubule atrophy. In the T1 group, necrosis was limited to pars recta cells and nucleolar segregation was often partial. In the T3.5 group, atrophy was extensive in both convoluted and straight tracts, the nucleolus was completely segregated and coiled body-like inclusions were detached from it. Ultrastructural analysis confirmed dose-dependent changes within straight proximal tubules, i.e., necrosis, apoptosis, nucleolar segregation, swollen mitochondria, vacuolization, and disrupted brush border. In conclusion, in the rat kidney HgCl(2) induced dose-dependent alterations not only in the cytoplasm but also in the nucleus of proximal tubule cells. These findings will be useful for better understanding of the pathogenesis of mercury nephrotoxicity and its genotoxic effect.