Mariangela Corsi

Adipokines and their Involvement as a Target of New Drugs

Globesity is referred to a global epidemic of obesity, affecting millions of individuals. Molecules released by the enlarged adipose tissue, most of which are pro-inflammatory, have been named adipokines. The present review deals with function, molecular targets and the potential clinical relevance of adipokines. Currently, more than 600 adipokines have been identified, many of them, including leptin, visfatin, resistin as well as Retinol Binding Protein4 may serve as informative markers for metabolic and cardiovascular diseases and play important roles in glucose homeostasis, insulin sensitivity as well as metabolic regulation of energy expenditure. Adiponectin on the contrary exerts anti-inflammatory and insulin sensitizing activity. Adiponectin has additional anti-atherogenic effects and low adiponectin serum concentrations are associated with increased risk for cardiovascular diseases. The understanding of the role of adipokines has provided a wealth of information that has opened great opportunities for new therapeutic advances. Adiponectin may be the most prominent example for the potential use of an adipokine in the treatment of obesity and obesity-associated metabolic diseases. In many studies, administration of recombinant adiponectin results in improved insulin sensitivity, increased insulin secretion and beneficial effects on body weight and hyperglycemia. Up-regulation of adiponectin/adiponectin receptors or enhancing adiponectin receptor function may be an interesting therapeutic strategy for obesity-linked insulin resistance. Moreover, the therapeutic use of combined amylin/leptin agonism (with pramlintide and metreleptin) demonstrated a significant weight-lowering effect in obese subjects. Therefore, adipokines may be clinically relevant either as therapeutic tools or as target in the treatment of obesity related diseases.

Anti-Oxidant and Anti-Inflammatory Activity of Ketogenic Diet: New Perspectives for Neuroprotection in Alzheimer’s Disease

The ketogenic diet, originally developed for the treatment of epilepsy in non-responder children, is spreading to be used in the treatment of many diseases, including Alzheimer’s disease. The main activity of the ketogenic diet has been related to improved mitochondrial function and decreased oxidative stress. B-Hydroxybutyrate, the most studied ketone body, has been shown to reduce the production of reactive oxygen species (ROS), improving mitochondrial respiration: it stimulates the cellular endogenous antioxidant system with the activation of nuclear factor erythroid-derived 2-related factor 2 (Nrf2), it modulates the ratio between the oxidized and reduced forms of nicotinamide adenine dinucleotide (NAD+/NADH) and it increases the efficiency of electron transport chain through the expression of uncoupling proteins. Furthermore, the ketogenic diet performs anti-inflammatory activity by inhibiting nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) activation and nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3) inflammasome as well as inhibiting histone deacetylases (HDACs), improving memory encoding. The underlying mechanisms and the perspectives for the treatment of Alzheimer’s disease are discussed.

Multidisciplinary approaches to stimulate wound healing.

New civil wars and waves of terrorism are causing crucial social changes, with consequences in all fields, including health care. In particular, skin injuries are evolving as an epidemic issue. From a physiological standpoint, although wound repair takes place more rapidly in the skin than in other tissues, it is still a complex organ to reconstruct. Genetic and clinical variables, such as diabetes, smoking, and inflammatory/immunological pathologies, are also important risk factors limiting the regenerative potential of many therapeutic applications. Therefore, optimization of current clinical strategies is critical. Here, we summarize the current state of the field by focusing on stem cell therapy applications in wound healing, with an emphasis on current clinical approaches being developed. These involve protocols for the ex vivo expansion of adipose tissue–derived mesenchymal stem cells by means of a patented Good Manufacturing Practice–compliant platelet lysate. Combinations of multiple strategies, including genetic modifications and stem cells, biomimetic scaffolds, and novel vehicles, such as nanoparticles, are also discussed as future approaches.

Interleukin-18 modulation in autism spectrum disorders

BackgroundAutism spectrum disorder (ASD) is a neurodevelopmental disease which affects 1 in 88 children. Its etiology remains basically unknown, but it is apparent that neuroinflammation is involved in disease development. Great attention has been focused on pro-inflammatory cytokines, and several studies have reported their dysfunction unbalance in serum as well as in the brain. The present work aimed at evaluating putative dysregulation of interleukin-18 (IL-18), a pro-inflammatory cytokine of the IL-1 family in the sera of patients with ASD of different grades, compared to healthy controls, as well as in postmortem brain samples obtained from patients with tuberous sclerosis as well as acute inflammatory diseases. Moreover, quantitative analysis of IL-18 was performed in the sera and brain obtained from Reeler mice, an experimental model of autism.MethodsSerum IL-18 levels were measured by ELISA. IL-18 was localized by immunohistochemical analysis in brain sections obtained from tuberous sclerosis and encephalitis patients, as well as from gender- and age-matched controls, and in the brain sections of both Reeler and wild-type mice. IL-18 was also quantified by Western blots in homogenates of Reeler and wild-type mice brains. IL-18 binding protein (IL-18BP) was evaluated in Reeler and wild-type mice plasma as well as in their brains (sections and homogenates).ResultsIL-18 content decreased in the sera of patients with autism compared to healthy subjects and in Reeler sera compared to wild-type controls. IL-18 was detected within glial cells and neurons in the brain of subjects affected by tuberous sclerosis and encephalitis whereas in healthy subjects, only a weak IL-18 positivity was detected at the level of glial cells. Western blot identified higher amounts of IL-18 in Reeler brain homogenates compared to wild-type littermates. IL-18BP was expressed in higher amounts in Reeler brain compared to the brain of wild-type mice, whereas no significant difference was detected comparing IL-18BP plasma levels.ConclusionsIL-18 is dysregulated in ASD patients. Further studies seemed necessary to clarify the molecular details behind IL-18 increase in the brain and IL-18 decrease in the sera of patients. An increase in the size of the patient cohort seems necessary to ascertain whether decreased IL-18 content in the sera can become a predictive biomarker of ASD and whether its measure, in combination with other markers (e.g., increased levels of brain-derived neurotrophic factor (BDNF)), may be included in a diagnostic panel.

Hunting the Risk NPY and ACE Polymorphisms as Predictors of Cardiovascular Diseases: Case Report and Review of the Literature

Many research efforts were addressed to identify individuals at high risk for multifactorial diseases, such as cardiovascular alterations and related diseases. Great interest was paid to investigate the genetic liability in multifactorial illnesses. The prognosis of high-risk patients might be greatly ameliorated using genetic predisposition risk factors, such as the polymorphisms of neuropeptide Y (NPY) and Angiotensin converting enzyme (ACE) genes. Epidemiologic results suggest that selected polymorphisms of both NPY and ACE might be helpful to improve the evaluation of patients, offering a powerful prognostic tool and paving the way to novel molecular therapeutic strategies. We present a case report of a male, sudden-death from myocardial infarction, presenting with left ventricular hypertrophy. The patient carried polymorphisms of ACE and NPY genes, respectively ACE genotype ID and NPY genotype T-399C, actually considered as risk factors.

Platelet Lysate-Derived Neuropeptide y Influences Migration and Angiogenesis of Human Adipose Tissue-Derived Stromal Cells

Neuropeptide Y (NPY), a powerful neurotransmitter of the central nervous system, is a key regulator of angiogenesis and biology of adipose depots. Intriguingly, its peripheral vascular and angiogenic powerful activity is strictly associated to platelets, which are source of clinical hemoderivates, such as platelet lysate (PL), routinely employed in several clinical applications as wound healing, and to preserve ex vivo the progenitor properties of the adipose stromal cells pool. So far, the presence of NPY in PL and its biological effects on the adipose stromal cell fraction (ASCs) have never been investigated. Here, we aimed to identify endogenous sources of NPY such as PL-based preparations and to investigate which biological properties PL-derived NPY is able to exert on ASCs. The results show that PL contains a high amount of NPY, which is in part also excreted by ASCs when stimulated with PL. The protein levels of the three main NPY subtype receptors (Y1, Y2, Y5) are unaltered by stimulation of ASCs with PL, but their inhibition through selective pharmacological antagonists, considerably enhances migration, and a parallel reduction of angiogenic features of ASCs including decrease in VEGF mRNA and intracellular calcium levels, both downstream targets of NPY. The expression of VEGF and NPY is enhanced within the sites of neovascularisation of difficult wounds in patients after treatment with leuco-platelet concentrates. Our data highlight the presence of NPY in PL preparations and its peripheral effects on adipose progenitors.

Macrophage polarization by the microenvironment of atherosclerotic plaques

Macrophages are key cellular mediators of innate immunity: they are positionally and transcriptionally programmed to respond to pathogens and environmental challenges. When activated by inflammatory signals in their microenvironment they develop into functionally and phenotypically distinct polarized subpopulations: classically activated macrophages, M1, characterized by cytotoxix/proinflammatory activity; alternatively activated macrophages, M2, characterized by anti-inflammatory/wound repair activity. M1 pro-inflammatory macrophages drive atherosclerotic plaques progression towards instability, cap fragilization and rupture. Our study provide new informations about the role exherted by IL-23 and its receptor in human carotid atherosclerotic plaque progression. We show the presence of IL-23 immunoreactivity, mRNA and protein in macrophages infiltrating human carotid atherosclerotic plaques. Our immunohistochemical analysis demonstrated a strong IL-23 immunoreactivity within the inflammatory infiltrate at the shoulder of the plaques, and at the level of cells lining the fibrous cap. FISH analysis confirmed the expression of IL-23 detected by immunohistochemistry. Immunofluorescence, followed by FISH analysis, showed that cells positive for IL-23 mRNA bind anti-CD68 mAb, thus indicating that these cells belong to the macrophage components of the inflammatory infiltrate. This result was further confirmed by double labelling experiments. IL-23 immunoreactivity was detected within the fibrous layer and co-localized with cells belonging to the monocyte-macrophage lineage as shown by their strong CD68- and CD14-related reaction. Clusters of double-positive cells were found at the border of the plaque, as well as in the subendothelial space. Immunohistochemistry and immunofluorescence showed a strong immunoreactivity for IL-23R at the level of inflammatory mononuclear cells accumulated within the plaque. In vitro, only M1 pro-inflammatory, but not M2 anti-inflammatory macrophages produced IL-23, upon stimulation with zymosan or bacterial lipopolysaccharide. Our results suggests that a hyperactive and highly pathogenic IL-23-IL-23R system drives chronic inflammation in atherosclerosis, while the presence of IL-23 proximal to the fibrous cap may contribute to the atherosclerotic plaque instability.

Ketogenic diet: a nutritional protocol for a non-pharmacological treatment of Alzheimer’s disease

Alzheimer’s disease (AD) is a progressively worsening disease that affects specific brain areas involved in spatial memory, short-term memory and has a negative impact on the individual, limiting his ability of independent life. AD remains asymptomatic for a considerable time before cognitive decline becomes clinically evident. For this reason, the establishment of appropriate nutritional protocols, in the early stage, may be more effective than any drug treatments in the fight against this disease. Ketogenic Diet (KD) is a diet high in fat, adequate-proteins and low carbohydrates producing ketone bodies (KBs) (alternative energy source to glucose for the brain). Nowadays, relations between KBs and cerebral Aβ accumulation are not clear. Most studies focus on the neuronal component and forget the vascular component of AD represented by the blood-brain barrier (BBB), located at the cerebral microvessels level. Consequently, it seems essential to focus on the BBB physiology, and in particular on the BBB’s functions of the receptors/transporters and enzymes involved in Aβ peptide transport and metabolism, to better understand the influence of a KD on the onset and the evolution of this disease. For 4 weeks, Wild type mice (129SV) were maintained on KD and Control Diet (CD). Glucose and Beta-hydroxybutyrate (BHB) levels were assessed in blood sample. Microvessel fractions were isolated from total brain and qPCR analyses were performed to study expression of transporters, receptors and enzymes involved in amyloid transport and metabolism at the BBB level. KD fed animals showed increased levels of BHB which was accompanied by an increased expression of Monocarboxylate Transporters 1 (MCT1) and Glucose transporter 1 (GLUT1) at the BBB level. There were not changes in the level of Glucose and body weight in these mice. In addition we observed modifications in the expression of some transporters involved in Aβ exchanges such as Low density lipoprotein receptor-related protein 1 (LRP1) and Multidrug resistance-associated protein 1 (MRP1). The expression of Aβ synthesis enzymes remains unchanged, instead an increase for the Aβ degradation enzyme Endothelin Converting Enzyme 1 (ECE1) was observed. These preliminary results show that dietary factors and in particular KD can modulate the expression of some actors implicated in brain Aβ metabolism at the BBB level.

Autologous leuco-platelet preparation promotes neoangiogenesis and wound healing

The rationale of our study was to test the potential of the autologous elements of peripheral white blood cells and platelets to promote neoangiogenesis, thereby overcoming hypoxemia, the major obstacle to the regeneration of the tissue. An highly innovative technique, based on an autologous leuco-platelet preparation, applied by direct infiltration to the ulcer was employed to treat 65 patients with ulcers of different etiologies. Hyaluronic acid was used as a scaffold, supplemented with autologous cells. Patients were followed up until complete healing of the lesions. Morphometric analysis was perfomed on histologic sections to determine the presence of neoangiogenesis. The wound healing was obtained in all cases after 2 until 22 months with this treatment (median time is 11.4 months). More than half of the patients recovered completely within the first 12 months. Morphometric analysis on histologic sections determined the presence of an abundant neovasculature in the close proximity of the infiltrations of leuco-platelet concentrate. Our data show that autologous leucoplatelet preparation layered onto ischemic ulcers may improve neoangiogenesis leading to wound healing. These findings suggest that this cell-based therapy may be a useful tool for the treatment for intractable skin ulcers resulting from diabetes, ischemia and collagen diseases.

Immunolocalization of pro-inflammatory cytokines within human aortic aneurysms

Much recent experimental evidence suggests that inflammatory reactions are involved in aneurysm formation and progression [1]. Vessel wall weakening has been attributed to the infiltration of a variety of cells, which leads to the upregulation of multiple cytokines [2]. A growing interest is currently focused in the definition of cytokines associated with the final stage of the disease that precedes the rupture. In the present study full aortic segments were collected from patients with thoracic aortic aneurysms, according to the declaration of Helsinki. Control aorta tissue from organ donors was included as reference. Microtome sections of paraffin embedded samples were analyzed for the presence of IL-17 and IL-23 positivity. Aortic sections were also stained with hematoxylin and eosin and Verhoeff-Van Gieson for elastin. Immunohistochemistry detected IL-17 and IL-23 positive cells at the level of adventitia and muscle cell layer. Our data reinforce previous results showing that IL-17 plays a central role in the promotion of vascular inflammation. The identification of main cytokines released during inflammatory processes underlying aneurysm formation and progression may lead to the set up of pharmaceutic strategies that may prove effective for the stabilization of aortic aneurysms.