Santa Mammana

Heme oxygenase-1 expression in peripheral blood mononuclear cells correlates with disease activity in multiple sclerosis.

Multiple sclerosis (MS) is an immunoinflammatory disease that affects the central nervous system. Heme oxygenase-1 (HO-1) is one of the three isoforms of the heme oxygenase enzyme that catabolyzes the degradation of heme into biliverdin with the production of free iron and CO. We show in this study that HO-1 expression is reduced in PBMCs of MS patients and that during exacerbation of the disease there is a significant downregulation of this enzyme. We conclude that HO-1 may play a significant role in the maintenance of immune homeostasis which is disrupted in autoimmune disorders, such as MS.

Comparative study of rapamycin and temsirolimus demonstrates superimposable anti-tumour potency on prostate cancer cells.

Rapamycin is a macrocyclic lactone currently used for the treatment of cancer and for the prevention of transplant rejection. The primary pharmacological mode of action of rapamycin occurs through the inhibition (blocking) of the mammalian target of rapamycin (mTOR). By doing so, rapamycin interferes with the phosphoinositide 3‐kinase (PI3K)‐Akt‐mTOR axis that controls several cellular functions involving cell growth, proliferation and angiogenesis. The frequent activation of the phosphoinositide 3‐kinase (PI3K)/AKT pathway in advanced prostate cancer has provided a rationale for the use of mTOR inhibitors in this setting. We carried out a comparative study on the effects of rapamycin and temsirolimus on the in vitro and in vivo growth of the prostate cancer cell lines, LnCap and PC3. Our results demonstrate that rapamycin and temsirolimus exert similar in vitro and in vivo anti‐proliferative effects against prostate cancer cells.

Hypomethylating Agent 5-Aza-2′-deoxycytidine (DAC) Ameliorates Multiple Sclerosis in Mouse Models

Increasing evidence supports the role of epigenetics in the development of autoimmune disorders and the possibility of using epigenetic modifying drugs in the context of MS has not yet been investigated. We have explored the effect of the hypomethylating agent 5‐aza‐2′‐deoxycytidine (DAC) in two murine models of experimental allergic encephalomyelitis (EAE). DAC treatment was associated with a significant amelioration of the clinical and histological hallmarks of EAE in both models. These effects were observed both in prophylactic and therapeutic regimens. The milder course of the disease was associated with a reduction in the number of spinal cord infiltrating lymphocytes and amelioration of the histopathological signs associated with EAE. In addition, increased transcript levels of anti‐inflammatory cytokines and decreased mRNA expression of pro‐inflammatory mediators were also observed. Finally, DAC treatment increased the percentage of circulating regulatory T cells by inducing Foxp3 expression via demethylation of a CpG island in Foxp3. J. Cell. Physiol. 229: 1918–1925, 2014.

Identification of novel targets for the diagnosis and treatment of liver fibrosis

Liver fibrosis is characterized by the excessive deposition of extracellular matrix (ECM) in the hepatic parenchyma and represents an intrinsic response to chronic injury, maintaining organ integrity when extensive necrosis or apoptosis occurs. Hepatic stellate cells (HSCs) are the major cell type responsible for liver fibrosis. Following liver injury, HSCs become activated and transdifferentiate into myofibroblasts (MFBs) that lead to intrahepatic ECM accumulation. In the present study, we performed a meta‑analysis of datasets which included whole-genome transcriptional data on HSCs in the quiescent and activated state from two different rodent species and identified commonly regulated genes. Several of the genes identified, including ECM components, metalloproteinases and growth factors, were found to be well‑known markers for HSC activation. However, other significant genes also appeared to play important roles in hepatic fibrosis. The elucidation of the molecular events underlying HSC activation may be key to the identification of potential novel pharmacological targets for the prevention and treatment of liver fibrosis.

Carbon monoxide-releasing molecule-A1 (CORM-A1) improves clinical signs of experimental autoimmune uveoretinitis (EAU) in rats

Uveitis is a sight-threatening inflammatory disease of the eye which represents the third leading cause of blindness in the developed countries. The conventional pharmacological treatment includes corticosteroids and immunosuppressive agents, which are limited by their side effects. New therapeutic strategies are thus strongly needed. Exogenously-administered carbon monoxide (CO) may represent an effective treatment for conditions characterized by a dysregulated inflammatory response. Carbon monoxide-releasing molecules (CORMs) are a novel group of compounds capable of carrying and liberating controlled quantities of CO. Among CORMs, CORM-A1 represents the first example of water soluble CO releaser. We show here that CORM-A1 under a late prophylactic regime is able to significantly ameliorate the natural course of experimental autoimmune uveoretinitis, a rodent model of immunoinflammatory posterior uveitis. The present study strongly supports the development of CORM-A1 as a potential new drug for treatment of patients with non-infectious posterior uveitis.

Apotransferrin inhibits interleukin-2 expression and protects mice from experimental autoimmune encephalomyelitis

Transferrin (Tf) has a major role in T cell activation and proliferation. Here, we investigated whether Tf exerts immunomodulatory effects on T cells and in development of T-cell driven experimental autoimmune encephalomyelitis (EAE). While treatment of concanavalin A-stimulated splenocytes with apotransferrin (ApoTf) did not affect release of IL-1β, TNF, IFN-γ, IL-17, IL-4, and IL-10, it markedly and dose-dependently down-regulated synthesis of IL-2 in these cells. ApoTf also inhibited IL-2 generation in purified CD3+ T cells and the effect was accompanied with down-regulation of MAPK p44/42 and NFκB signaling. Despite impeded IL-2 release, proliferation of splenocytes was not inhibited by ApoTf. Importantly, ApoTf ameliorated EAE in mice and significantly reduced ex vivo IL-2 production in proteolipid protein-specific lymphocytes. Thus ApoTf may be a promising beneficial agent for multiple sclerosis.

Pathogenic role for macrophage migration inhibitory factor in glioblastoma and its targeting with specific inhibitors as novel tailored therapeutic approach

Macrophage Migration Inhibitory Factor (MIF) is a pro-inflammatory cytokine expressed by a variety of cell types. Although MIF has been primarily studied for its role in the pathogenesis of autoimmune diseases, it has also been shown to promote tumorigenesis and it is over expressed in various malignant tumors. MIF is able to induce angiogenesis, cell cycle progression, and to block apoptosis. As tailored therapeutic approaches for the inhibition of endogenous MIF are being developed, it is important to evaluate the role of MIF in individual neoplastic conditions that may benefit from specific MIF inhibitors. Along with this line, in this paper, we have reviewed the evidence of the involvement of MIF in the etiopathogenesis and progression of glioblastoma and the preclinical data suggesting the possible use of specific MIF inhibition as a potential novel therapeutic strategy for brain tumors.

Involvement of the Nrf2/HO‐1/CO axis and therapeutic intervention with the CO‐Releasing Molecule CORM‐A1, in a murine model of Autoimmune Hepatitis

Concanavalin A (ConA)‐induced hepatitis is an experimental model of human autoimmune hepatitis induced in rodents by i.v. injection of Con A. The disease is characterized by increase in serum levels of transaminases and massive immune infiltration of the livers. Type 1, type 2, and type 17 cytokines play a pathogenic role in the development of ConA‐induced hepatitis. To understand further the immunoregulatory mechanisms operating in the development and regulation of ConA‐induced hepatitis, we have evaluated the role of the anti‐inflammatory pathway Nrf2/HO‐1/CO (Nuclear Factor E2‐related Factor 2/Heme Oxygenase‐1/Carbon Monoxide) in this condition and determined whether the in vivo administration of CO via the CO‐releasing molecule (CORM) CORM‐A1, influences serological and histological development of Con‐A‐induced hepatitis. We have firstly evaluated in silico the genes belonging to the Nrf2/HO‐1/CO pathway that are involved in the pathogenesis of autoimmune hepatitis (AIH). The data obtained from the in silico study demonstrate that a significant number of genes modulated in the liver of ConA‐challenged mice belong to the Nrf2 pathway; on the other hand, the administration of CORM‐A1 determines an improvement in several sero‐immunological and histological parameters, and it is able to modulate genes identified by the in silico analysis. Collectively, our data indicate that the Nrf2/HO‐1/CO pathway is fundamental for the regulation of the immune responses, and that therapeutic intervention aimed at its modulation by CORM‐A1 may represent a valuable strategy to be considered for the treatment of autoimmune hepatitis in humans.

Effects of NO-Hybridization on the Immunomodulatory Properties of the HIV Protease Inhibitors Lopinavir and Ritonavir

HIV protease inhibitors (PIs) are antiretroviral agents, which have been found to also affect several cellular processes, such as inflammation and cell progression. In studies on non‐steroidal, anti‐inflammatory drugs, the addition of a nitric oxide (NO) moiety has been shown to both reduce their toxicity and enhance their pharmacological efficacy. Along this line of research, several derivatives of PIs have been synthesized by covalent attachment of NO moiety to the parental molecules. Previous work has indicated that NO‐hybridization of the prototypical PI, Saquinavir leads to a derivative named Saquinavir‐NO that while retaining the antiretroviral effect, acquires antitumoural and immunomodulatory properties along with reduced toxicity in vitro and in vivo. These data prompted us to evaluate the effects of NO‐hybridization on two other PIs, Lopinavir and Ritonavir. The two NO‐derivatives were compared head to head with their parental compounds on human primary peripheral blood mononuclear cells as well as on human primary macrophages. Lopinavir‐NO and Lopinavir were also screened in an in vivo model of autoimmune hepatitis. Our results prove that Lopinavir‐NO exerts markedly superior effects as compared to the parental compound both in vitro and in vivo. On the contrary, Ritonavir‐NO effects overlapped those of Ritonavir. These data demonstrate that NO‐hybridization of Lopinavir generates a derivative with significantly stronger immunomodulatory effects that are apparently related to an action of the compound on T‐cell secretory capacity. Lopinavir‐NO deserves additional studies for its possible use in T‐cell‐mediated autoimmune diseases including, but not limited to autoimmune hepatitis.

Acceleration of SLE-like syndrome development in NZBxNZW F1 mice by beta-glucan.

Beta-glucans are naturally occurring polysaccharides that exert important immunostimulatory activities. In the present study, we evaluated whether beta-glucans could modulate the development and the course of systemic lupus erythematosus (SLE). To this aim, we employed the classical model of SLE represented by the F1 hybrid between the NZB and NZW mouse strains which develop severe lupus-like phenotypes comparable to that of SLE patients. The administration of beta-glucan was associated to a more aggressive development of the disease and a worse prognosis, as observed from the clinical, biochemical and histopathological data. This finding implies that restraint should be practised in the possible use of beta-glucans as immunomodulators in human therapy in the context of SLE.