Claudio Lonati

Cyclosporine-A treatment inhibits the expression of metabotropic glutamate receptors in rat thymus

We have evaluated the expression of metabotropic glutamate receptors (mGluR subtypes 2/3, 4 and 5) in rat thymus under normal and experimental conditions after 2 and 21 days of cyclosporine-A treatment. In normal rats, immunohistochemical analysis showed that expression of mGluRs was high in dendritic cells and lymphocytes of the medulla whereas it was weak in lymphocytes of the cortex. However, there were some differences in the expression of mGluRs subtypes. mGluR5 showed strong expression in lymphocytes of medulla and dendritic cells. mGluR2/3 and mGluR4 were moderately expressed in lymphocytes and dendritic cells of the medulla and weakly in cortical lymphocytes. Immunoblotting showed moderate levels of mGluR2/3 and mGluR4 and strong levels of mGluRS. After 2 days of cyclosporine-A treatment, we observed by immunohistochemistry and immunoblotting a distinct decrease in all mGluRs and their expression had almost completely disappeared after 21 days of treatment. The results clearly indicate that: 1) mGluR2/3, 4 and 5 are widely expressed in thymic cells; 2) the mGluR5 subtype is expressed most strongly in medullary cells; and 3) cyclosporine-A rapidly inhibits expression of all mGluR subtypes after 2 days of treatment and their complete disappearance after prolonged treatment. These findings may indicate a possible mechanism by which cyclosporine-A produces its immunosupressive effects.

Obesity-related dysfunction of the aorta and prevention by melatonin treatment in ob/ob mice

In this study, we hypothesized that melatonin administration can minimize alterations in aorta morphology in an animal model of obesity (ob/ob mice). The animals were divided into four groups: (i) control lean mice, (ii) control lean mice treated with melatonin, (iii) ob/ob mice and (iv) ob/ob mice treated with melatonin. The synthetic melatonin was dissolved in 1% ethanol and added to the drinking water from postnatal week 5-13 at a final dose of 100 mg/kg body weight/day. Compared with the obese mice, melatonin intake was associated with a significant decrease in body weight and water consumption. Histological analysis showed that the aortic wall of ob/ob mice had a high Tunica media/lumen ratio and that the elastic fibers in the media layer appeared disrupted and degraded. Moreover, the aorta of ob/ob mice displayed a higher degree of collagen accumulation in the Tunica media compared to the normal aorta. The aorta of ob/ob mice treated with melatonin had a lower Tunica media/lumen ratio and collagen accumulation in comparison with untreated ob/ob mice. Our results showed that whereas melatonin had no apparent histological effects on the aorta in lean mice with normal weight, its administration in ob/ob mice can lead to a reduction in body weight and can ameliorate aorta histopathological dysfunction. This experimental study indicates an apparent protective role for melatonin on the aorta in obesity and melatonin could possibly be an effective tool in the management of obesity-related vascular complications.

A review of the effects of dietary silicon intake on bone homeostasis and regeneration

OBJECTIVE Increasing evidences suggest that dietary Silicon (Si) intake, is positively correlated with bone homeostasis and regeneration, representing a potential and valid support for the prevention and improvement of bone diseases, like osteoporosis. This review, aims to provide the state of art of the studies performed until today, in order to investigate and clarify the beneficial properties and effects of silicates, on bone metabolism. METHODS We conducted a systematic literature search up to March 2013, using two medical databases (Pubmed and the Cochrane Library), to review the studies about Si consumption and bone metabolism. RESULTS We found 45 articles, but 38 were specifically focused on Si studies. CONCLUSION RESULTS showed a positive relationship between dietary Si intake and bone regeneration.

Platelet preparations in neuronal cell differentiation

Concentrated Growth Factors (CGF) is a platelet rich preparation that has the important feature of a tight fibrin network and containing a large number of growth factors possessing great regenerative potentialities [1]. The regeneration of nervous system is one of the mail goal of regenerative medicine. The aim of this study is to test the in vitro CGF effects on both differentiated and undifferentiated SH-SY5Y cells, derived from human neuroblastoma. To induce differentiation, SH-SY5Y cells have been treated with Retinoic Acid (RA) 10µM, in both basal and complete medium and in the presence and absence of CGF. After 72 hours, different parameters have been investigated: the morphological characteristics of the cells, the cell proliferation, the cellular vitality using the MTT test, the CGF and/or RA differentiation property and the immunocytochemical analysis of neuronal specific markers (NeuN, Sinaptophisine, β-III-tubulin, Nestin). Moreover the NGF (Nerve Growth Factor) and BDNF (Brain Derived Growth Factor) release have been assayed by ELISA test. Our results obtained suggest that treatment with CGF, also used alone, positively affects cell differentiation and neuronal phenotype regulating the expression of the neuronal markers and improving the outgrowth of neurites. Taken together these results seems to be promised into new approaches for neuronal regeneration using platelet preparations.

A comparison of melatonin and α-lipoic acid in the reduction of oxidative stress in L6 rat skeletal muscle cells

Aging is an universal, inevitable and multifactorial biological process, which causes progressive loss of function and an increased risk of death. Free radicals have been implicated in aging process, causing cumulative oxidative damage to crucial macromolecules and are responsible for failure of multiple physiological mechanisms [1]. Muscle mass and function are gradually lost during aging leading to neuromuscular disorders (such as fibromyalgia, sarcopenia, etc.). The indoleamine melatonin is able to prevent oxidative stress both through its free radical scavenging effect and by increasing endogenous antioxidant activity and so protecting against oxidative damage induced by drugs, toxins and different diseases [2]. Herein, we evaluated the susceptibility of rat L6 skeletal muscle cells to induced oxidative stress due to the exposure of cells to hydrogen peroxide and the potential protective effects of the pre-treatment with melatonin (MelapureTM by Flamma S.p.A.), compared to the known beneficial effect of alpha-lipoic acid. Our results showed that hydrogen peroxide-induced obvious oxidative stress, increasing the expression of tumour necrosis-alpha and in turn of nuclear factor kappa-B, overriding the endogenous defence mechanisms and alterating the mitochondrial structure. In contrast, the pre-treatment with melatonin of the hydrogen peroxide-exposed cells increased endogenous antioxidant enzymes, including superoxide dismutase-2 and heme oxygenase-1, and ameliorated significantly both the oxidative stress damage and the mitochondrial alterations, that are known to be involved in aging and aging related diseases. In conclusion, melatonin had important anti-oxidant and anti-aging effects at the level of skeletal muscle in vitro.

Prostate cancer and novel ways to deliver melatonin

Prostate cancer is the major cause of cancer death in men and angiogenesis has been shown to play a critical role in the progression of the disease. The anticancer activity of the indole melatonin (MT) has been explained to be due to its immunomodulatory, anti-prolferative and anti-oxidant effects, whereas at present no data are available about its possible influence on the angiogenesis in prostatic cancer, which has been shown to be one of the main biological mechanisms responsible for tumor dissemination [1]. Hence, this study tested whether MT is active in prostate cancer therapy and speculated about the possible mechanism underlying this activity. Moreover, alternative ways to deliver the indole molecule were also evaluated. To this purpose, an in vivo model of human prostate tumor LNCaP cells xenografted into nude athymic mice was used. MT has been administered i.p. as saline (1 mg/kg, n=13) and encapsulated into solid lipid nanoparticles (SLN) (1mg/kg n=13) or transdermally by Criopass therapy (4 mg/kg, n=14). For all treatments the administration schedule was for 6 weeks, 3 treatments for week. For each treatment controls were also included. At the end animals were sacrificed and the tumors evaluated for size, morphology and biochemical markers. The mean tumor volume/body weight (2.62±1.92 mm3/g, n=49 ) of all MT-treated groups at sacrifice was significantly lower vs controls (5.98±1.56 mm3/g, n=25). Vascularization was impaired in all MT treated tumors, and nuclear positivity for Ki 67, a cellular marker for proliferation, showed a decrease. Laser treatment alone showed a mild effect, magnified by MT addition. In conclusion we confirmed the efficacy of MT in impairing cancer angiogenesis and proliferation and the efficacy of different alternative and novel ways to deliver MT on prostate tumor which use may be easily transferred also to clinical trials on humans.