The dangerous "West Coast Swing" by hyperglycaemia and chronic stress in the mouse hippocampus: Role of kynurenine catabolism.

Growing epidemiological studies highlight a bi-directional relationship between depressive symptoms and diabetes mellitus. However, the detrimental impact of their co-existence on mental health suggests the need to treat this comorbidity as a separate entity rather than the two different pathologies. Herein, we characterized the peculiar mechanisms activated in mouse hippocampus from the concurrent development of hyperglycaemia, characterizing the different diabetes subtypes, and chronic stress, recognized as a possible factor predisposing to major depression. Our work demonstrates that kynurenine overproduction, leading to apoptosis in the hippocampus, is triggered in a different way depending on hyperglycaemia or chronic stress. Indeed, in the former, kynurenine appears produced by infiltered macrophages whereas, in the latter, peripheral kynurenine preferentially promotes resident microglia activation. In this scenario, QA, derived from kynurenine catabolism, appears a key mediator causing glutamatergic synapse dysfunction and apoptosis, thus contributing to brain atrophy. We demonstrated that the coexistence of hyperglycaemia and chronic stress worsened hippocampal damage through alternative mechanisms, such as GLUT-4 and BDNF down-expression, denoting mitochondrial dysfunction and apoptosis on one hand and evoking the compromission of neurogenesis on the other. Overall, in the degeneration of neurovascular unit, hyperglycaemia and chronic stress interacted each other as the partners of a "West Coast Swing" in which the leading role can be assumed alternatively by each partner of the dance. The comprehension of these mechanisms can open novel perspectives in the management of diabetic/depressed patients, but also in the understanding the pathogenesis of other neurodegenerative disease characterized by the compromission of hippocampal function.

The Postbiotic Properties of Butyrate in the Modulation of the Gut Microbiota: The Potential of Its Combination with Polyphenols and Dietary Fibers.

The gut microbiota is a diverse bacterial community consisting of approximately 2000 species, predominantly from five phyla: Firmicutes, Bacteroidetes, Actinobacteria, Proteobacteria, and Verrucomicrobia. The microbiota's bacterial species create distinct compounds that impact the host's health, including well-known short-chain fatty acids. These are produced through the breakdown of dietary fibers and fermentation of undigested carbohydrates by the intestinal microbiota. The main short-chain fatty acids consist of acetate, propionate, and butyrate. The concentration of butyrate in mammalian intestines varies depending on the diet. Its main functions are use as an energy source, cell differentiation, reduction in the inflammatory process in the intestine, and defense against oxidative stress. It also plays an epigenetic role in histone deacetylases, thus helping to reduce the risk of colon cancer. Finally, butyrate affects the gut-brain axis by crossing the brain-blood barrier, making it crucial to determine the right concentrations for both local and peripheral effects. In recent years, there has been a significant amount of attention given to the role of dietary polyphenols and fibers in promoting human health. Polyphenols and dietary fibers both play crucial roles in protecting human health and can produce butyrate through gut microbiota fermentation. This paper aims to summarize information on the key summits related to the negative correlation between intestinal microbiota diversity and chronic diseases to guide future research on determining the specific activity of butyrate from polyphenols and dietary fibers that can carry out these vital functions.

Pathophysiological Aspects of Muscle Atrophy and Osteopenia Induced by Chronic Constriction Injury (CCI) of the Sciatic Nerve in Rats.

Skeletal muscle atrophy is a condition characterized by a loss of muscle mass and muscle strength caused by an imbalance between protein synthesis and protein degradation. Muscle atrophy is often associated with a loss of bone mass manifesting as osteoporosis. The aim of this study was to evaluate if chronic constriction injury (CCI) of the sciatic nerve in rats can be a valid model to study muscle atrophy and consequent osteoporosis. Body weight and body composition were assessed weekly. Magnetic resonance imaging (MRI) was performed on day zero before ligation and day 28 before sacrifice. Catabolic markers were assessed via Western blot and Quantitative Real-time PCR. After the sacrifice, a morphological analysis of the gastrocnemius muscle and Micro-Computed Tomography (Micro-CT) on the tibia bone were performed. Rats that underwent CCI had a lower body weight increase on day 28 compared to the naive group of rats (p < 0.001). Increases in lean body mass and fat mass were also significantly lower in the CCI group (p < 0.001). The weight of skeletal muscles was found to be significantly lower in the ipsilateral hindlimb compared to that of contralateral muscles; furthermore, the cross-sectional area of muscle fibers decreased significantly in the ipsilateral gastrocnemius. The CCI of the sciatic nerve induced a statistically significant increase in autophagic and UPS (Ubiquitin Proteasome System) markers and a statistically significant increase in Pax-7 (Paired Box-7) expression. Micro-CT showed a statistically significant decrease in the bone parameters of the ipsilateral tibial bone. Chronic nerve constriction appeared to be a valid model for inducing the condition of muscle atrophy, also causing changes in bone microstructure and leading to osteoporosis. Therefore, sciatic nerve constriction could be a valid approach to study muscle-bone crosstalk and to identify new strategies to prevent osteosarcopenia.

The Effect of an Innovative Combination of Bergamot Polyphenolic Fraction and Cynara cardunculus L. Extract on Weight Gain Reduction and Fat Browning in Obese Mice.

Obesity is one of the world's most serious public health issues, with a high risk of developing a wide range of diseases. As a result, focusing on adipose tissue dysfunction may help to prevent the metabolic disturbances commonly associated with obesity. Nutraceutical supplementation may be a crucial strategy for improving WAT inflammation and obesity and accelerating the browning process. The aim of this study was to perform a preclinical "proof of concept" study on Bergacyn®, an innovative formulation originating from a combination of bergamot polyphenolic fraction (BPF) and Cynara cardunculus (CyC), for the treatment of adipose tissue dysfunction. In particular, Bergacyn® supplementation in WD/SW-fed mice at doses of 50 mg/kg given orally for 12 weeks, was able to reduce body weight and total fat mass in the WD/SW mice, in association with an improvement in plasma biochemical parameters, including glycemia, total cholesterol, and LDL levels. In addition, a significant reduction in serum ALT levels was highlighted. The decreased WAT levels corresponded to an increased weight of BAT tissue, which was associated with a downregulation of PPARγ as compared to the vehicle group. Bergacyn® was able to restore PPARγ levels and prevent NF-kB overexpression in the WAT of mice fed a WD/SW diet, suggesting an improved oxidative metabolism and inflammatory status. These results were associated with a significant potentiation of the total antioxidant status in WD/SW mice. Finally, our data show, for the first time, that Bergacyn® supplementation may be a valuable approach to counteract adipose tissue dysfunction and obesity-associated effects on cardiometabolic risk.

The Contribution of Gut Microbiota and Endothelial Dysfunction in the Development of Arterial Hypertension in Animal Models and in Humans.

The maintenance of the physiological values of blood pressure is closely related to unchangeable factors (genetic predisposition or pathological alterations) but also to modifiable factors (dietary fat and salt, sedentary lifestyle, overweight, inappropriate combinations of drugs, alcohol abuse, smoking and use of psychogenic substances). Hypertension is usually characterized by the presence of a chronic increase in systemic blood pressure above the threshold value and is an important risk factor for cardiovascular disease, including myocardial infarction, stroke, micro- and macro-vascular diseases. Hypertension is closely related to functional changes in the endothelium, such as an altered production of vasoconstrictive and vasodilator substances, which lead to an increase in vascular resistance. These alterations make the endothelial tissue unresponsive to autocrine and paracrine stimuli, initially determining an adaptive response, which over time lead to an increase in risk or disease. The gut microbiota is composed of a highly diverse bacterial population of approximately 1014 bacteria. A balanced intestinal microbiota preserves the digestive and absorbent functions of the intestine, protecting from pathogens and toxic metabolites in the circulation and reducing the onset of various diseases. The gut microbiota has been shown to produce unique metabolites potentially important in the generation of hypertension and endothelial dysfunction. This review highlights the close connection between hypertension, endothelial dysfunction and gut microbiota.

The muscle to bone axis (and viceversa): An encrypted language affecting tissues and organs and yet to be codified?

Skeletal muscles and bone tissue form the musculoskeletal apparatus, a complex system essential for the voluntary movement. The loss of muscle mass and muscle strength is often associated with a loss of bone mass, in a "hazardous duet" which implies the co-existence of sarcopenia-osteoporosis and exposes patients to a deterioration in quality of life and increased mortality. From the mechanostat theory to the recent definition of the osteosarcopenia syndrome, many aspects of muscle-bone interaction have been investigated in recent decades. The mechanical interaction is now accepted, considering the close anatomical relationship between the two tissues, however, much remains to be discovered regarding the biochemical muscle-bone interaction. Skeletal muscle has been defined as an endocrine organ capable of exerting an action on other tissues. Myokines, bioactive polypeptides released by the muscle, could represent the encrypted message in the communication between muscle and bone. These two tissues have a reciprocal influence on their metabolisms and respond in a similar way to the multiple external factors. The aim of this review is to stimulate the understanding of the encrypted language between muscle and bone, highlighting the role of catabolic pathways and oxidative stress in the musculoskeletal apparatus to elucidate the shared mechanisms and the similarity of response to the same stimuli by different tissues. Our understanding of muscle-bone interactions it could be useful to identify and develop new strategies to treat musculoskeletal diseases, together with pharmacological, nutritional and exercise-based approaches, which are already in use for the treatment of these pathologies.

Cholesterol homeostasis: Researching a dialogue between the brain and peripheral tissues.

Cholesterol homeostasis is a highly regulated process in human body because of its several functions underlying the biology of cell membranes, the synthesis of all steroid hormones and bile acids and the need of trafficking lipids destined to cell metabolism. In particular, it has been recognized that peripheral and central nervous system cholesterol metabolism are separated by the blood brain barrier and are regulated independently; indeed, peripherally, it depends on the balance between dietary intake and hepatic synthesis on one hand and its degradation on the other, whereas in central nervous system it is synthetized de novo to ensure brain physiology. In view of this complex metabolism and its relevant functions in mammalian, impaired levels of cholesterol can induce severe cellular dysfunction leading to metabolic, cardiovascular and neurodegenerative diseases. The aim of this review is to clarify the role of cholesterol homeostasis in health and disease highlighting new intriguing aspects of the cross talk between its central and peripheral metabolism.

The Effect of Ferula communis Extract in Escherichia coli Lipopolysaccharide-Induced Neuroinflammation in Cultured Neurons and Oligodendrocytes.

In recent decades, interest in natural compounds has increased exponentially due to their numerous beneficial properties in the treatment of various acute and chronic diseases. A group of plant derivatives with great scientific interest is terpenic compounds. Among the plants richest in terpenes, the genus Ferula L. is one of the most representative, and ferutinin, the most common sesquiterpene, is extracted from the leaves, rhizome, and roots of this plant. As reported in the scientific literature, ferutinin possesses antioxidant and anti-inflammatory properties, as well as valuable estrogenic properties. Neurodegenerative and demyelinating diseases are devastating conditions for which a definite cure has not yet been established. The mechanisms involved in these diseases are still poorly understood, and oxidative stress is considered to be both a key modulator and a common denominator. In the proposed experimental system, co-cultured human neurons (SH-SY5Y) and human oligodendrocytes (MO3.13) were treated with the pro-inflammatory agent lipopolysaccharide at a concentration of 1 µg/mL for 24 h or pretreated with ferutinin (33 nM) for 24 h and subsequently exposed to lipopolysaccharide 1 µg/mL for 24 h. Further studies would, however, be needed to establish whether this natural compound can be used as a support strategy in pathologies characterized by progressive inflammation and oxidative stress phenomena.

Potential of Nutraceutical Supplementation in the Modulation of White and Brown Fat Tissues in Obesity-Associated Disorders: Role of Inflammatory Signalling.

The high incidence of obesity is associated with an increasing risk of several chronic diseases such as cardiovascular disease, type 2 diabetes and non-alcoholic fatty liver disease (NAFLD). Sustained obesity is characterized by a chronic and unsolved inflammation of adipose tissue, which leads to a greater expression of proinflammatory adipokines, excessive lipid storage and adipogenesis. The purpose of this review is to clarify how inflammatory mediators act during adipose tissue dysfunction in the development of insulin resistance and all obesity-associated diseases. In particular, we focused our attention on the role of inflammatory signaling in brown adipose tissue (BAT) thermogenic activity and the browning of white adipose tissue (WAT), which represent a relevant component of adipose alterations during obesity. Furthermore, we reported the most recent evidence in the literature on nutraceutical supplementation in the management of the adipose inflammatory state, and in particular on their potential effect on common inflammatory mediators and pathways, responsible for WAT and BAT dysfunction. Although further research is needed to demonstrate that targeting pro-inflammatory mediators improves adipose tissue dysfunction and activates thermogenesis in BAT and WAT browning during obesity, polyphenols supplementation could represent an innovative therapeutic strategy to prevent progression of obesity and obesity-related metabolic diseases.

Effects of C-Peptide Replacement Therapy on Bone Microarchitecture Parameters in Streptozotocin-Diabetic Rats.

C-peptide therapy protects against diabetic micro- and macrovascular damages and neuropatic complications. However, to date, the role of C-peptide in preventing diabetes-related bone loss has not been investigated. Our aim was to evaluate if C-peptide infusion improves bone quality in diabetic rats. Twenty-three male Wistar rats were randomly divided into three groups: normal control group; sham diabetic control group; diabetic plus C-peptide group. Diabetes was induced by streptozotocin injection and C-peptide was delivered subcutaneously for 6 weeks. We performed micro-CT and histological testing to assess several trabecular microarchitectural parameters. At the end, diabetic plus C-peptide rats had a higher serum C-peptide (p = 0.02) and calcium (p = 0.04) levels and tibia weight (p = 0.02) than the diabetic control group. The diabetic plus C-peptide group showed a higher trabecular thickness and cross-sectional thickness than the diabetic control group (p = 0.01 and p = 0.03). Both the normal control and diabetic plus C-peptide groups had more Runx-2 and PLIN1 positive cells in comparison with the diabetic control group (p = 0.045 and p = 0.034). Diabetic rats receiving C-peptide had higher quality of trabecular bone than diabetic rats not receiving this treatment. If confirmed, C-peptide could have a role in improving bone quality in diabetes.

The Contribution of Endothelial Dysfunction in Systemic Injury Subsequent to SARS-Cov-2 Infection.

SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) infection is associated, alongside with lung infection and respiratory disease, to cardiovascular dysfunction that occurs at any stage of the disease. This includes ischemic heart disease, arrhythmias, and cardiomyopathies. The common pathophysiological link between SARS-CoV-2 infection and the cardiovascular events is represented by coagulation abnormalities and disruption of factors released by endothelial cells, which contribute in maintaining the blood vessels into an anti-thrombotic state. Thus, early alteration of the functionality of endothelial cells, which may be found soon after SARS-CoV-2 infection, seems to represent the major target of a SARS CoV-2 disease state and accounts for the systemic vascular dysfunction that leads to a detrimental effect in terms of hospitalization and death accompanying the disease. In particular, the molecular interaction of SARS-CoV-2 with the ACE2 receptor located in the endothelial cell surface, either at the pulmonary and systemic level, leads to early impairment of endothelial function, which, in turn, is followed by vascular inflammation and thrombosis of peripheral blood vessels. This highlights systemic hypoxia and further aggravates the vicious circle that compromises the development of the disease, leading to irreversible tissue damage and death of people with SARS CoV-2 infection. The review aims to assess some recent advances to define the crucial role of endothelial dysfunction in the pathogenesis of vascular complications accompanying SARS-CoV-2 infection. In particular, the molecular mechanisms associated with the interaction of SARS CoV-2 with the ACE2 receptor located on the endothelial cells are highlighted to support its role in compromising endothelial cell functionality. Finally, the consequences of endothelial dysfunction in enhancing pro-inflammatory and pro-thrombotic effects of SARS-CoV-2 infection are assessed in order to identify early therapeutic interventions able to reduce the impact of the disease in high-risk patients.

The Potential for Natural Antioxidant Supplementation in the Early Stages of Neurodegenerative Disorders.

The neurodegenerative process is characterized by the progressive ultrastructural alterations of selected classes of neurons accompanied by imbalanced cellular homeostasis, a process which culminates, in the later stages, in cell death and the loss of specific neurological functions. Apart from the neuronal cell impairment in selected areas of the central nervous system which characterizes many neurodegenerative diseases (e.g., Alzheimer's Disease, Parkinson's Disease, Huntington's Disease, etc.), some alterations may be found in the early stages including gliosis and the misfolding or unfolding accumulation of proteins. On the other hand, several common pathophysiological mechanisms can be found early in the course of the disease including altered oxidative metabolism, the loss of cross-talk among the cellular organelles and increased neuroinflammation. Thus, antioxidant compounds have been suggested, in recent years, as a potential strategy for preventing or counteracting neuronal cell death and nutraceutical supplementation has been studied in approaching the early phases of neurodegenerative diseases. The present review will deal with the pathophysiological mechanisms underlying the early stages of the neurodegenerative process. In addition, the potential of nutraceutical supplementation in counteracting these diseases will be assessed.

Role of TSPO/VDAC1 Upregulation and Matrix Metalloproteinase-2 Localization in the Dysfunctional Myocardium of Hyperglycaemic Rats.

Clinical management of diabetic cardiomyopathy represents an unmet need owing to insufficient knowledge about the molecular mechanisms underlying the dysfunctional heart. The aim of this work is to better clarify the role of matrix metalloproteinase 2 (MMP-2) isoforms and of translocator protein (TSPO)/voltage-dependent anion-selective channel 1 (VDAC1) modulation in the development of hyperglycaemia-induced myocardial injury. Hyperglycaemia was induced in Sprague-Dawley rats through a streptozocin injection (35 mg/Kg, i.p.). After 60 days, cardiac function was analysed by echocardiography. Nicotinamide Adenine Dinucleotide Phosphate NADPH oxidase and TSPO expression was assessed by immunohistochemistry. MMP-2 activity was detected by zymography. Superoxide anion production was estimated by MitoSOX™ staining. Voltage-dependent anion-selective channel 1 (VDAC-1), B-cell lymphoma 2 (Bcl-2), and cytochrome C expression was assessed by Western blot. Hyperglycaemic rats displayed cardiac dysfunction; this response was characterized by an overexpression of NADPH oxidase, accompanied by an increase of superoxide anion production. Under hyperglycaemia, increased expression of TSPO and VDAC1 was detected. MMP-2 downregulated activity occurred under hyperglycemia and this profile of activation was accompanied by the translocation of intracellular N-terminal truncated isoform of MMP-2 (NT-MMP-2) from mitochondria-associated membrane (MAM) into mitochondria. In the onset of diabetic cardiomyopathy, mitochondrial impairment in cardiomyocytes is characterized by the dysregulation of the different MMP-2 isoforms. This can imply the generation of a "frail" myocardial tissue unable to adapt itself to stress.

Ferula L. Plant Extracts and Dose-Dependent Activity of Natural Sesquiterpene Ferutinin: From Antioxidant Potential to Cytotoxic Effects.

The employment studies of natural extracts in the prevention and treatment of several diseases highlighted the role of different species of genus Ferula L., belonging to the Apiaceae family, dicotyledonous plants present in many temperate zones of our planet. Ferula communis L. is the main source of sesquiterpene ferutinin, a bioactive compound studied both in vitro and in vivo, because of different effects, such as phytoestrogenic, antioxidant, anti-inflammatory, but also antiproliferative and cytotoxic activity, performed in a dose-dependent and cell-dependent way. The present review will focus on the molecular mechanisms involved in the different activities of Ferutinin, starting from its antioxidant potential at low doses until its ionophoric property and the subsequent mitochondrial dysfunction induced through administration of high doses, which represent the key point of its anticancer action. Furthermore, we will summarize the data acquired from some experimental studies on different cell types and on several diseases. The results obtained showed an important antioxidant and phytoestrogenic regulation with lack of typical side effects related to estrogenic therapy. The preferential cell death induction for tumor cell lines suggests that ferutinin may have anti-neoplastic properties, and may be used as an antiproliferative and cytotoxic agent in an estrogen dependent and independent manner. Nevertheless, more data are needed to clearly understand the effect of ferutinin in animals before using it as a phytoestrogen or anticancer drug.

The effect of bergamot polyphenolic fraction on lipid transfer protein system and vascular oxidative stress in a rat model of hyperlipemia.

BACKGROUND: Experimental and epidemiological studies show that bergamot polyphenolic fraction (BPF) ameliorates the serum lipemic profile, normalizes blood pressure and improves non alcoholic fatty liver disease in patients suffering from metabolic syndrome. Despite this evidence, the molecular mechanisms responsible for these beneficial effects remain unclear. The aim of our study is to clarify the effects of BPF on the lipoprotein assembly and to identify oxidative stress biomarkers correlating hyperlipidaemia and BPF-induced metabolic changes. METHODS: Male Wistar rats (180-200 g) were randomly assigned to receive a standard diet, a hypercholesterolemic diet or a hypercholesterolemic diet+BPF (20 mg/Kg/rat daily, gavage), respectively, for 90 days. Total cholesterol (tChol), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides (TG) and fasting plasma glucose were evaluated at the baseline as well as at the end of the treatment. To assess the effect of BPF on the Lipid Transfer Protein System, detection of ACAT, LCAT, CETP, PON1, Apo A1 and Apo B have also been carried out. Finally, the lipid peroxidation biomarker (TBARS) and oxyLDL were also measured. RESULTS: BPF prevented tChol, LDL-C, TG and fasting plasma glucose enhancement and improved HDL-C. Treatment of hyperlipæmic rats with BPF significantly restored altered the serum concentration of lipemic biomarkers and the activity of ACAT, LCAT, CETP and PON1, an effect accompanied by the concomitant normalization of Apo A1 and APO B levels. In addition, TBARS levels were reduced significantly by the treatment with BPF. CONCLUSIONS: BPF prevents diet-induced alteration of the lipid profile in rats, counteracting oxidative stress and improving the dysregulation of the Lipid Transfer Protein System. These data add new insights into the molecular mechanisms underlying the beneficial role of BPF in the therapy of hyperlipidaemia, thus suggesting a novel approach in the prevention of cardiovascular disease.

Myelin Disturbances Produced by Sub-Toxic Concentration of Heavy Metals: The Role of Oligodendrocyte Dysfunction.

Evidence has been accumulated demonstrating that heavy metals may accumulate in various organs, leading to tissue damage and toxic effects in mammals. In particular, the Central Nervous System (CNS) seems to be particularly vulnerable to cumulative concentrations of heavy metals, though the pathophysiological mechanisms is still to be clarified. In particular, the potential role of oligodendrocyte dysfunction and myelin production after exposure to subtoxic concentration I confirmed. It is ok of heavy metals is to be better assessed. Here we investigated on the effect of sub-toxic concentration of several essential (Cu2 +, Cr3 +, Ni2 +, Co2+) and non-essential (Pb2 +, Cd2+, Al3+) heavy metals on human oligodendrocyte MO3.13 and human neuronal SHSY5Y cell lines (grown individually or in co-culture). MO3.13 cells are an immortal human-human hybrid cell line with the phenotypic characteristics of primary oligodendrocytes but following the differentiation assume the morphological and biochemical features of mature oligodendrocytes. For this reason, we decided to use differentiated MO3.13 cell line. In particular, exposure of both cell lines to heavy metals produced a reduced cell viability of co-cultured cell lines compared to cells grown separately. This effect was more pronounced in neurons that were more sensitive to metals than oligodendrocytes when the cells were grown in co-culture. On the other hand, a significant reduction of lipid component in cells occurred after their exposure to heavy metals, an effect accompanied by substantial reduction of the main protein that makes up myelin (MBP) in co-cultured cells. Finally, the effect of heavy metals in oligodendrocytes were associated to imbalanced intracellular calcium ion concentration as measured through the fluorescent Rhod-2 probe, thus confirming that heavy metals, even used at subtoxic concentrations, lead to dysfunctional oligodendrocytes. In conclusion, our data show, for the first time, that sub-toxic concentrations of several heavy metals lead to dysfunctional oligodendrocytes, an effect highlighted when these cells are co-cultured with neurons. The pathophysiological mechanism(s) underlying this effect is to be better clarified. However, imbalanced intracellular calcium ion regulation, altered lipid formation and, finally, imbalanced myelin formation seem to play a major role in early stages of heavy metal-related oligodendrocyte dysfunction.

Modulation of Nitric Oxide Synthases by Oxidized LDLs: Role in Vascular Inflammation and Atherosclerosis Development.

The maintenance of physiological levels of nitric oxide (NO) produced by eNOS represents a key element for vascular endothelial homeostasis. On the other hand, NO overproduction, due to the activation of iNOS under different stress conditions, leads to endothelial dysfunction and, in the late stages, to the development of atherosclerosis. Oxidized LDLs (oxLDLs) represent the major candidates to trigger biomolecular processes accompanying endothelial dysfunction and vascular inflammation leading to atherosclerosis, though the pathophysiological mechanism still remains to be elucidated. Here, we summarize recent evidence suggesting that oxLDLs produce significant impairment in the modulation of the eNOS/iNOS machinery, downregulating eNOS via the HMGB1-TLR4-Caveolin-1 pathway. On the other hand, increased oxLDLs lead to sustained activation of the scavenger receptor LOX-1 and, subsequently, to NFkB activation, which, in turn, increases iNOS, leading to EC oxidative stress. Finally, these events are associated with reduced protective autophagic response and accelerated apoptotic EC death, which activates atherosclerotic development. Taken together, this information sheds new light on the pathophysiological mechanisms of oxLDL-related impairment of EC functionality and opens new perspectives in atherothrombosis prevention.

The Role of Endothelial Dysfunction in Peripheral Blood Nerve Barrier: Molecular Mechanisms and Pathophysiological Implications.

The exchange of solutes between the blood and the nerve tissue is mediated by specific and high selective barriers in order to ensure the integrity of the different compartments of the nervous system. At peripheral level, this function is maintained by the Blood Nerve Barrier (BNB) that, in the presence, of specific stressor stimuli can be damaged causing the onset of neurodegenerative processes. An essential component of BNB is represented by the endothelial cells surrounding the sub-structures of peripheral nerves and increasing evidence suggests that endothelial dysfunction can be considered a leading cause of the nerve degeneration. The purpose of this review is to highlight the main mechanisms involved in the impairment of endothelial cells in specific diseases associated with peripheral nerve damage, such as diabetic neuropathy, erectile dysfunction and inflammation of the sciatic nerve.

Anti-oxidant effect of bergamot polyphenolic fraction counteracts doxorubicin-induced cardiomyopathy: Role of autophagy and c-kitposCD45negCD31neg cardiac stem cell activation.

Doxorubicin (DOXO) is one of the most widely used antineoplastic drugs. Despite its highly beneficial effects against several malignancies, the clinical use of DOXO is often associated to cardiomyopathy that leads to congestive heart failure. Here we investigated the antioxidant and cardioprotective effects of a polyphenol-rich fraction of citrus bergamot (BPF), in DOXO-induced cardiac damage in rats. Moreover, we evaluated the effect of BPF on cardiomyocyte survival and resident endogenous cardiac stem/progenitor cell (eCSC) activation. Adult male Wistar rats were i.p. injected with saline (serving as controls, CTRL, n = 10), BPF (20 mg/kg daily for 14 consecutive days, n = 10), DOXO (6 doses of 2,5 mg/Kg from day 1 to day 14, n = 10), and DOXO + BPF (n = 10). Animals were then sacrificed 7 days later (i.e., at 21 days). DOXO administration reduced cardiac function at 21 days, an adverse effect significantly attenuated in animals receiving DOXO + BPF. No changes were detected in rats receiving just saline or BPF alone. The cardioprotective effect of BPF on DOXO acute toxicity was also associated with a significant antioxidant effect coupled with protective autophagy restoration, and attenuation of cardiomyocyte apoptosis and reactive hypertrophy. Finally, treatment of rats with BPF prevented eCSCs attrition by DOXO which was followed by a limited but significant increase of newly-formed BrdU+ cardiomyocytes. In conclusion, BPF reduces DOXO-induced cardiotoxicity by counteracting reactive oxygen species (ROS) overproduction, thereby restoring protective autophagy and attenuating cardiomyocyte apoptosis and pathologic remodeling. This beneficial effects on the early toxicity of DOXO is associated with enhanced CSCs survival and regenerative potential. Overall these data point to a potential clinical role by diet supplementation with polyphenol-rich fraction of citrus bergamot in counteracting antracycline-induced cardiomyopathy.

Ethanol-induced cardiomyocyte toxicity implicit autophagy and NFkB transcription factor.

Chronic ethanol (EtOH) consumption causes early detrimental consequences in many tissues including the myocardium, though the molecular mechanisms leading to the alcoholic cardiomyopathy (ACM) still remain to be elucidated. Here, we studied several biomolecular changes occurring in cardiomyoblasts after their exposure to sublethal concentrations of EtOH and the potential synergistic effect with methylmercury (MM) or doxorubicin (DOXO), which are known to produce direct myocardial dysfunction. In addition, the possible role of autophagic responses and Nuclear Factor kappa-B (NFkB) modulation in early post-alcoholic myocardial damage has been investigated. H9c2 rat cardiomyoblasts were incubated for fifteen days with a sub-lethal concentrations of EtOH (1-1000 µM). In particular, treatment of H9c2 cells with EtOH produced an increase of reactive oxygen species (ROS) and the activation of autophagy. Furthermore, chronic exposure to EtOH, was accompanied by a translocation of NFkB into the nucleus dose-dependently. Finally, co-incubation of EtOH (1-1000 µM) with sublethal concentrations of MM or DOXO showed a prominent apoptotic death of cardiomyoblasts accompanied by ROS overproduction, autophagy activation and by an increased nuclear translocation of NFkB as compared to untreated cells. Thus, EtOH produces early changes in cardiomyoblasts characterized by oxidative stress, reactive autophagy and NFkB modulation at concentrations unable to produce direct cell death. Combination of EtOH with cardiotoxic pollutants or drugs makes the cardiomyocyte vulnerable to exogenous insults leading to apoptosis. These data contribute to better identify molecular mechanisms underlying early stages of alcoholic cardiomyopathy and suggest novel strategies to counteract integrated risk of cardiotoxicity in chronic alcohol consumption.