Coenzyme A fueling with pantethine limits autoreactive T cell pathogenicity in experimental neuroinflammation.

BACKGROUND: Immune cell metabolism governs the outcome of immune responses and contributes to the development of autoimmunity by controlling lymphocyte pathogenic potential. In this study, we evaluated the metabolic profile of myelin-specific murine encephalitogenic T cells, to identify novel therapeutic targets for autoimmune neuroinflammation. METHODS: We performed metabolomics analysis on actively-proliferating encephalitogenic T cells to study their overall metabolic profile in comparison to resting T cells. Metabolomics, phosphoproteomics, in vitro functional assays, and in vivo studies in experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis (MS), were then implemented to evaluate the effect of metabolic targeting on autoreactive T cell pathogenicity. Finally, we confirmed the translational potential of our targeting approach in human pro-inflammatory T helper cell subsets and in T cells from MS patients. RESULTS: We found that autoreactive encephalitogenic T cells display an altered coenzyme A (CoA) synthesis pathway, compared to resting T cells. CoA fueling with the CoA precursor pantethine (PTTH) affected essential immune-related processes of myelin-specific T cells, such as cell proliferation, cytokine production, and cell adhesion, both in vitro and in vivo. Accordingly, pre-clinical treatment with PTTH before disease onset inhibited the development of EAE by limiting T cell pro-inflammatory potential in vivo. Importantly, PTTH also significantly ameliorated the disease course when administered after disease onset in a therapeutic setting. Finally, PTTH reduced pro-inflammatory cytokine production by human T helper 1 (Th1) and Th17 cells and by T cells from MS patients, confirming its translational potential. CONCLUSION: Our data demonstrate that CoA fueling with PTTH in pro-inflammatory and autoreactive T cells may represent a novel therapeutic approach for the treatment of autoimmune neuroinflammation.

TIM-1 glycoprotein binds the adhesion receptor P-selectin and mediates T cell trafficking during inflammation and autoimmunity.

Selectins play a central role in leukocyte trafficking by mediating tethering and rolling on vascular surfaces. Here we have reported that T cell immunoglobulin and mucin domain 1 (TIM-1) is a P-selectin ligand. We have shown that human and murine TIM-1 binds to P-selectin, and that TIM-1 mediates tethering and rolling of T helper 1 (Th1) and Th17, but not Th2 and regulatory T cells on P-selectin. Th1 and Th17 cells lacking the TIM-1 mucin domain showed reduced rolling in thrombin-activated mesenteric venules and inflamed brain microcirculation. Inhibition of TIM-1 had no effect on naive T cell homing, but it reduced T cell recruitment in a skin hypersensitivity model and blocked experimental autoimmune encephalomyelitis. Uniquely, the TIM-1 immunoglobulin variable domain was also required for P-selectin binding. Our data demonstrate that TIM-1 is a major P-selectin ligand with a specialized role in T cell trafficking during inflammatory responses and the induction of autoimmune disease.

Multidimensional improvements induced by an intensive obesity inpatients rehabilitation programme.

PURPOSE: To analyse the short-term effectiveness of an intensive multidimensional inpatient programme specifically developed for patients with severe obesity. METHODS: A multidisciplinary team managed a 3-week residential programme characterised by the integration of nutritional and physical rehabilitation with psychological and educational intervention. All patients consecutively admitted in 10 months were analysed at admission and discharge for changes in the following domains: anthropometry (weight, body mass index (BMI), waist and neck circumferences), cardiovascular risk factors (glycaemia, HbA1c, lipid profile, blood pressure), quality of life, eating behaviour, and physical performance (VO2peak by incremental cycle ergometer test, 6-min walking test (6MWT), chair stands test). RESULTS: 136 subjects (61% females, median age 52.7 years) with obesity (mean BMI 43.2 kg/m2) and multiple comorbidities were analysed. A 3.9% BMI reduction and a reduction in waist (-3.8%) and neck (-3.3%) circumferences were observed. Glycaemic control was achieved in 68% of patients with uncontrolled diabetes at admission. Blood pressure control was achieved in all patients with uncontrolled hypertension at admission. Total cholesterol (-16%), LDL-cholesterol (-19%) and triglycerides (-9%) were significantly reduced. Psychometric assessment showed improvements in quality of life perception and binge eating disorder. Finally, a significant improvement in physical performance (+4.7% improvement in VO2peak, with longer distances in 6MWT and a higher number of standings) was observed. CONCLUSIONS: Our preliminary data prove that a 3-week programme determined a clinically significant multi-dimensional improvement in patients with severe obesity. Long-term follow-up data are needed to confirm the efficacy of our rehabilitation setting.

Regulatory T cells suppress the late phase of the immune response in lymph nodes through P-selectin glycoprotein ligand-1.

Regulatory T cells (Tregs) maintain tolerance toward self-antigens and suppress autoimmune diseases, although the underlying molecular mechanisms are unclear. In this study, we show that mice deficient for P-selectin glycoprotein ligand-1 (PSGL-1) develop a more severe form of experimental autoimmune encephalomyelitis than wild type animals do, suggesting that PSGL-1 has a role in the negative regulation of autoimmunity. We found that Tregs lacking PSGL-1 were unable to suppress experimental autoimmune encephalomyelitis and failed to inhibit T cell proliferation in vivo in the lymph nodes. Using two-photon laser-scanning microscopy in the lymph node, we found that PSGL-1 expression on Tregs had no role in the suppression of early T cell priming after immunization with Ag. Instead, PSGL-1-deficient Tregs lost the ability to modulate T cell movement and failed to inhibit the T cell-dendritic cell contacts and T cell clustering essential for sustained T cell activation during the late phase of the immune response. Notably, PSGL-1 expression on myelin-specific effector T cells had no role in T cell locomotion in the lymph node. Our data show that PSGL-1 represents a previously unknown, phase-specific mechanism for Treg-mediated suppression of the persistence of immune responses and autoimmunity induction.

The pathogenetic bases of sarcopenia.

Aging is accompanied by involuntary loss of skeletal muscle mass, strength and function, called sarcopenia. The mechanisms underlying the development of sarcopenia are not completely understood and most likely multi-factorial, but significant progress has been made over the past few years to identify some of the major contributors. Besides life style-related factors, as diet and physical activity, sarcopenia seems to be also determined by hormonal dysregulation, chronic inflammatory status, ectopic adipose tissue accumulation, neurological and vascular changes associated with aging. The present mini-review focused on the basic factors that primarily impact muscle homeostasis in older subjects. A better understanding of cellular mechanism leading to sarcopenia is required to establish evidence-based intervention in order to prevent onset of symptoms associated with sarcopenia and to extend the time free from disability in older adults.

Adipose-derived mesenchymal stem cells ameliorate chronic experimental autoimmune encephalomyelitis.

Mesenchymal stem cells (MSCs) represent a promising therapeutic approach for neurological autoimmune diseases; previous studies have shown that treatment with bone marrow-derived MSCs induces immune modulation and reduces disease severity in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. Here we show that intravenous administration of adipose-derived MSCs (ASCs) before disease onset significantly reduces the severity of EAE by immune modulation and decreases spinal cord inflammation and demyelination. ASCs preferentially home into lymphoid organs but also migrates inside the central nervous system (CNS). Most importantly, administration of ASCs in chronic established EAE significantly ameliorates the disease course and reduces both demyelination and axonal loss, and induces a Th2-type cytokine shift in T cells. Interestingly, a relevant subset of ASCs expresses activated alpha 4 integrins and adheres to inflamed brain venules in intravital microscopy experiments. Bioluminescence imaging shows that alpha 4 integrins control ASC accumulation in inflamed CNS. Importantly, we found that ASC cultures produce basic fibroblast growth factor, brain-derived growth factor, and platelet-derived growth factor-AB. Moreover, ASC infiltration within demyelinated areas is accompanied by increased number of endogenous oligodendrocyte progenitors. In conclusion, we show that ASCs have clear therapeutic potential by a bimodal mechanism, by suppressing the autoimmune response in early phases of disease as well as by inducing local neuroregeneration by endogenous progenitors in animals with established disease. Overall, our data suggest that ASCs represent a valuable tool for stem cell-based therapy in chronic inflammatory diseases of the CNS.

Effects of an Intensive Inpatient Rehabilitation Program in Elderly Patients with Obesity.

OBJECTIVE: The aim of this study was to assess the short-term effectiveness of an intensive inpatient multidimensional rehabilitation program (MRP), including diet, exercise, and behavioral therapy, in elderly patients with severe obesity. METHODS: Forty-four elderly patients (old; age 69.3 ± 3.5 years, BMI 41.9 ± 14.9) were analyzed against 215 younger patients (young; age 48.2 ± 18.5 years, BMI 43.9 ± 9.4), who were used as controls. All patients underwent MRP, based on group therapy guided by a multidisciplinary team (physicians, dietitians, exercise trainers, psychologists). We evaluated changes in anthropometry, cardiovascular risk factors, physical fitness, quality of life, and eating behavior. RESULTS: After 3 weeks of MRP, we observed a reduction in body weight (old -3.8%, young -4.3%), BMI (old -3.9%, young -4.4%), waist circumference (old -3.4%, young -4.1%), total cholesterol (old -14.0%, young -15.0%), and fasting glucose (old -8.3%, young -8.1%), as well as improved performance in the Six-Minute-Walk Test (old +28.7%, young +15.3%), chair-stand test (old +24.8%, young +26.9%), and arm-curl test (old +15.2%, young +27.3%). Significant improvement was registered in all other analyzed domains. CONCLUSION: Our 3-week MRP provided significant clinical and functional improvement, which was similar between elderly and younger patients with severe obesity. In the long-term, this may be translated into better quality of life, through better management of obesity-associated morbidities and reduced frailty.

Morphological and Functional Changes in the Peritumoral Adipose Tissue of Colorectal Cancer Patients.

OBJECTIVE: The role of peritumoral adipose tissue (AT) has not been extensively studied in colorectal cancer (CRC). METHODS: This study was conducted in 20 male subjects undergoing elective surgery for CRC. The differences between the peritumoral visceral adipose tissue (P-VAT), visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT) of the patients were described via immunohistochemistry and molecular biology analyses. The interactions between adipocytes and a colon cancer cell line were also investigated by using an in vitro coculture system. RESULTS: The analyses revealed that adipocytes near the tumor were significantly smaller than the adipocytes from other sites. The P-VAT was preferentially infiltrated by a CD68+/CD163+/IDO- macrophage subset with a prevalent reparative inflammatory response, while the macrophages identified in VAT and SAT mainly presented inflammatory features. Furthermore, the P-VAT presented a higher expression of adiponectin compared with other sites. Morphological analysis in vitro showed that after a few days of coculture, 3T3-L1 adipocytes were reduced in number and size with an increase in lipolysis rate and dedifferentiation phenomena. CONCLUSIONS: This study reveals important morphological and functional changes in the AT surrounding the tumor as an increase in lipolysis and in adiponectin-producing adipocytes, preferentially infiltrated by a macrophage subset, with prevalent reparative inflammatory response.

Adipocytes WNT5a mediated dedifferentiation: a possible target in pancreatic cancer microenvironment.

A significant epidemiological association between obesity and pancreatic ductal adenocarcinoma (PDAC) has previously been described, as well as a correlation between the degree of pancreatic steatosis, PDAC risk and prognosis. The underlying mechanisms are still not completely known.After co-culture of 3T3-L1 adipocytes and MiaPaCa2 with an in vitro transwell system we observed the appearance of fibroblast-like cells, along with a decrease in number and size of remaining adipocytes. RT-PCR analyses of 3T3-L1 adipocytes in co-culture showed a decrease in gene expression of typical markers of mature adipocytes, in parallel with an increased expression of fibroblast-specific and reprogramming genes. We found an increased WNT5a gene and protein expression early in MiaPaCa2 cells in co-culture. Additionally, EMSA of c-Jun and AP1 in 3T3-L1 demonstrated an increased activation in adipocytes after co-culture. Treatment with WNT5a neutralizing antibody completely reverted the activation of c-Jun and AP1 observed in co-cultured adipocytes.Increasing doses of recombinant SFRP-5, a competitive inhibitor for WNT5a receptor, added to the co-culture medium, were able to block the dedifferentiation of adipocytes in co-culture.These data support a WNT5a-mediated dedifferentiation process with adipocytes reprogramming toward fibroblast-like cells that might profoundly influence cancer microenvironment.

Neutrophils promote Alzheimer's disease-like pathology and cognitive decline via LFA-1 integrin.

Inflammation is a pathological hallmark of Alzheimer's disease, and innate immune cells have been shown to contribute to disease pathogenesis. In two transgenic models of Alzheimer's disease (5xFAD and 3xTg-AD mice), neutrophils extravasated and were present in areas with amyloid-ß (Aß) deposits, where they released neutrophil extracellular traps (NETs) and IL-17. Aß42 peptide triggered the LFA-1 integrin high-affinity state and rapid neutrophil adhesion to integrin ligands. In vivo, LFA-1 integrin controlled neutrophil extravasation into the CNS and intraparenchymal motility. In transgenic Alzheimer's disease models, neutrophil depletion or inhibition of neutrophil trafficking via LFA-1 blockade reduced Alzheimer's disease-like neuropathology and improved memory in mice already showing cognitive dysfunction. Temporary depletion of neutrophils for 1 month at early stages of disease led to sustained improvements in memory. Transgenic Alzheimer's disease model mice lacking LFA-1 were protected from cognitive decline and had reduced gliosis. In humans with Alzheimer's disease, neutrophils adhered to and spread inside brain venules and were present in the parenchyma, along with NETs. Our results demonstrate that neutrophils contribute to Alzheimer's disease pathogenesis and cognitive impairment and suggest that the inhibition of neutrophil trafficking may be beneficial in Alzheimer's disease.

Phenotypic shift of adipocytes by cholecalciferol and 1α,25 dihydroxycholecalciferol in relation to inflammatory status and calcium content.

Recent experimental data seem to suggest a relevant role for 1,25[OH]2cholecalciferol (1,25[OH]2D3) in adipocyte physiology and pathophysiology, with some studies showing adipogenic and pro-inflammatory properties, and others lipolytic and anti-inflammatory functions. Moreover, to our knowledge, the role of cholecalciferol (D3) in adipocytes function is still not known. Therefore, the aim of this study was to investigate in vitro the effects of 1,25[OH]2D3, as well as of D3, in 3T3-L1 adipocytes in basal and inflammatory conditions, testing the effects of different calcium concentrations in adipocytes culture medium. In 3T3-L1 adipocytes, CYP27A1 and CYP27B1 mRNA were detected in basal conditions and induced after D3 treatment. Pre-treatment of 3T3-L1 adipocytes not only with 1,25[OH]2D3, but also with D3 before inflammatory stimulation, significantly prevented the increase in gene expression and protein secretion of IL-6 and TNF-α, and significantly increased IL-10 mRNA and protein production compared with adipocytes treated only with lipopolysaccharide (LPS). Biological effects of D3 were still present after inhibition of P450 activity with ketokonazole. LPS determined a decrease in cell area compared with controls, paralleled by a significant increase in optical density (OD) of lipid droplets, whereas 1,25[OH]2D3 and D3 alone significantly increased adipocytes area and decreased OD. Pretreatment with both forms of vitamin D preserved cells from the reduction in their area observed after LPS treatment. LPS decreased more the area of cells grown in a high calcium medium than of adipocytes grown in a low calcium medium. In the presence of a high calcium medium, 1,25(OH)2D3 treatment preserved cell area, maintaining its anti-inflammatory and adipogenic properties. In conclusion our results show that D3, besides 1,25[OH]2D3, presents anti-inflammatory effects on 3T3-L1, as well as that adipocytes have the enzymatic pathways necessary to locally regulate the production of active forms of vitamin D, capable of influencing adipocyte phenotype and function.

Predictors of Ectopic Fat in Humans.

In the last decade there has been increasing focus on body fat distribution, rather than on the degree of obesity. More recently, great interest has also been dedicated to ectopic fat deposition in overnourished individuals that reflects a failure of the system of intracellular lipid homeostasis, which, in normal conditions, prevents lipotoxicity in the organs, by confining lipid overload to cells specifically designed to store large quantities of surplus calories, the white adipocytes. Consequently, excess body weight leads to fat infiltration of multiple organs including liver, pancreas, skeletal muscle, and heart thus forming "ectopic fat". Although overfeeding is considered the main predictor of ectopic fat deposition, other factors may be also involved. The purpose of this review is to evaluate the current available data on the predictors of ectopic fat deposition in humans.

Vascular inflammation in central nervous system diseases: adhesion receptors controlling leukocyte-endothelial interactions.

Leukocyte trafficking from the blood into the tissues represents a key process during inflammation and requires multiple steps mediated by adhesion molecules and chemoattractants. Inflammation has a detrimental role in several diseases, and in such cases, the molecular mechanisms controlling leukocyte migration are potential therapeutic targets. Over the past 20 years, leukocyte migration in the CNS has been investigated almost exclusively in the context of stroke and MS. Experimental models of ischemic stroke have led to the characterization of adhesion molecules controlling leukocyte migration during acute inflammation, whereas EAE, the animal model of MS, has provided similar data for chronic inflammation. Such experiments have led to clinical trials of antileukocyte adhesion therapy, with consistently positive outcomes in human subjects with MS, showing that interference with leukocyte adhesion can ameliorate chronic inflammatory CNS diseases. This review summarizes our current understanding of the roles of adhesion molecules controlling leukocyte-endothelial interactions in stroke and MS, focusing on recently discovered, novel migration mechanisms. We also discuss the growing evidence suggesting a role for vascular inflammation and leukocyte trafficking in neurodegenerative diseases such as AD. Moreover, we highlight recent findings suggesting a role for leukocyte-endothelial interactions in the pathogenesis of seizures and epilepsy, thus linking endothelial activation and leukocyte trafficking to neuronal electrical hyperactivity. These emerging roles for leukocytes and leukocyte adhesion mechanisms in CNS diseases provide insight into the mechanisms of brain damage and may contribute to the development of novel therapeutic strategies.