Role of Adaptive Immunity in Alcoholic Liver Disease

Stimulation of innate immunity is increasingly recognized to play an important role in the pathogenesis of alcoholic liver disease (ALD), while the contribution of adaptive immunity has received less attention. Clinical and experimental data show the involvement of Th-1 and Th-17 T-lymphocytes in alcoholic hepatitis. Nonetheless, the mechanisms by which alcohol triggers adaptive immunity are still incompletely characterized. Patients with advanced ALD have circulating IgG and T-lymphocytes recognizing epitopes derived from protein modification by hydroxyethyl free radicals and end products of lipid-peroxidation. High titers of IgG against lipid peroxidation-derived antigens are associated with an increased hepatic production of proinflammatory cytokines/chemokines. Moreover, the same antigens favor the breaking of self-tolerance towards liver constituents. In particular, autoantibodies against cytochrome P4502E1 (CYP2E1) are evident in a subset of ALD patients. Altogether these results suggest that allo- and autoimmune reactions triggered by oxidative stress might contribute to hepatic inflammation during the progression of ALD

Inflammatory processes involved in NASH-related hepatocellular carcinoma

: Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related death worldwide. In the recent years nonalcoholic fatty liver disease (NAFLD) is becoming a growing cause of HCCs and the incidence of NAFLD-related HCCs is expected to further dramatically increase by the next decade. Chronic inflammation is regarded as the driving force of NAFLD progression and a key factor in hepatic carcinogenesis. Hepatic inflammation in NAFLD results from the persistent stimulation of innate immunity in response to hepatocellular injury and gut dysbiosis as well as by the activation of adaptive immunity. However, the relative roles of innate and adaptive immunity in the processes leading to HCC are still incompletely characterized. This is due to the complex interplay between different liver cell populations, which is also strongly influenced by gut-derived bacterial products, metabolic/nutritional signals. Furthermore, carcinogenic mechanisms in NAFLD/NASH appear to involve the activation of signals mediated by hypoxia inducible factors. This review discusses recent data regarding the contribution of different inflammatory cells to NAFLD-related HCC and their possible impact on patient response to current treatments

Annexin A1 treatment prevents the evolution to fibrosis of experimental nonalcoholic steatohepatitis

: Annexin A1 (AnxA1) is an important effector in the resolution of inflammation which is involved in modulating hepatic inflammation in nonalcoholic steatohepatitis (NASH). In the present study, we have investigated the possible effects of treatment with AnxA1 for counteracting the progression of experimental NASH. NASH was induced in C57BL/6 mice by feeding methionine-choline deficient (MCD) or Western diets (WDs) and the animals were treated for 4-6 weeks with human recombinant AnxA1 (hrAnxA1; 1 µg, daily IP) or saline once NASH was established. In both experimental models, treatment with hrAnxA1 improved parenchymal injury and lobular inflammation without interfering with the extension of steatosis. Furthermore, administration of hrAnxA1 significantly attenuated the hepatic expression of α1-procollagen and TGF-β1 and reduced collagen deposition, as evaluated by collagen Sirius Red staining. Flow cytometry and immunohistochemistry showed that hrAnxA1 did not affect the liver recruitment of macrophages, but strongly interfered with the formation of crown-like macrophage aggregates and reduced their capacity of producing pro-fibrogenic mediators like osteopontin (OPN) and galectin-3 (Gal-3). This effect was related to an interference with the acquisition of a specific macrophage phenotype characterized by the expression of the Triggering Receptor Expressed on Myeloid cells 2 (TREM-2), CD9 and CD206, previously associated with NASH evolution to cirrhosis. Collectively, these results indicate that, beside ameliorating hepatic inflammation, AnxA1 is specifically effective in preventing NASH-associated fibrosis by interfering with macrophage pro-fibrogenic features. Such a novel function of AnxA1 gives the rationale for the development of AnxA1 analogs for the therapeutic control of NASH evolution

SerpinB3 promotes pro-fibrogenic responses in activated hepatic stellate cells

SerpinB3 is a hypoxia- and hypoxia-inducible factor-2\u3b1-dependent cystein protease inhibitor that is up-regulated in hepatocellular carcinoma and in parenchymal cells during chronic liver diseases (CLD). SerpinB3 up-regulation in CLD patients has been reported to correlate with the extent of liver fibrosis and the production of transforming growth factor-\u3b21, but the actual role of SerpinB3 in hepatic fibrogenesis is still poorly characterized. In the present study we analyzed the pro-fibrogenic action of SerpinB3 in cell cultures and in two different murine models of liver fibrosis. "In vitro" experiments revealed that SerpinB3 addition to either primary cultures of human activated myofibroblast-like hepatic stellate cells (HSC/MFs) or human stellate cell line (LX2 cells) strongly up-regulated the expression of genes involved in fibrogenesis and promoted oriented migration, but not cell proliferation. Chronic liver injury by CCl4 administration or by feeding a methionine/choline deficient diet to transgenic mice over-expressing human SerpinB3 in hepatocytes confirmed that SerpinB3 over-expression significantly increased the mRNA levels of pro-fibrogenic genes, collagen deposition and \u3b1SMA-positive HSC/MFs as compared to wild-type mice, without affecting parenchymal damage. The present study provides for the first time evidence that hepatocyte release of SerpinB3 during CLD can contribute to liver fibrogenesis by acting on HSC/MFs

An Alternative Treatment Strategy for Complicated Chronic Wounds: Negative Pressure Therapy over Mesh Skin Graft

Extensive skin defect represents a real problem and major challenge in plastic and reconstructive surgery. On one hand, skin grafts offer a practical method to deal with skin defects despite their unsuitability for several complicated wounds. On the other hand, negative pressure wound therapy (NPWT), applied before skin grafting, promotes granulation tissue growth. The aim of the study is to evaluate the improvement in wound healing given by the merger of these two different approaches. We treated 23 patients for large wounds of multiple factors. Of these, 15 were treated with the application of V.A.C.® Therapy (KCI Medical S.r.l., Milan, Italy), in combination with skin grafts after a prior unsuccessful treatment of 4 weeks with mesh skin grafts and dressings. Another 8 were treated with only mesh skin graft. Pain reduction and wound area reduction were found statistically significant (p < 0.0009, p < 0.0001). Infection was resolved in almost all patients. According to our study, the use of the negative pressure wound therapy over mesh skin grafts is significantly effective especially in wounds resistant to conventional therapies, thereby improving the rate of skin graft take

DAVID The First 6U Cubesat Mission of the Italian Space Agency Programme Iperdrone as Demonstration of New On Orbit Services Performed by Space Drones

The Italian Space Agency is promoting a roadmap for the design, manufacturing and operation of a new space reentry drone. The Iperdrone program will qualify a new type of operative mission, through an incremental phased approach. The program includes, as first step, the demonstration of inspection services for the International Space Station, optimizing the EVA activities and increasing the in space experimentation opportunities. The paper will present the status of development of the first mission, which will demonstrate the system\u27s capabilities such as proximity operations, inspection and interaction with a target, including a close rendez-vous demonstration. The first mission, DAVID to be launched within 2023, is based on a 6U cubesat architecture

Adenosine A 2a receptor stimulation prevents hepatocyte lipotoxicity and non-alcoholic steatohepatitis (NASH) in rats

A B S T R A C T NEFA (non-esterified &apos;free&apos; fatty acid)-mediated lipotoxicity plays a critical role in the pathogenesis of NASH (non-alcoholic steatohepatitis). In the light of the growing need for new therapeutic options for NASH, we investigated the action of A 2a R (adenosine A 2a receptor) stimulation against lipotoxicity. The effects of the A 2a R agonist CGS21680 [2-p-(2-carboxyethyl)phenethylamino-5 -Nethylcarboxyamidoadenosine] were evaluated &apos;in vitro&apos; in liver cells exposed to SA (stearic acid) and &apos;in vivo&apos; in rats with NASH induced by 8 weeks of feeding with an MCD diet (methionine/cholinedeficient diet). In cultured hepatocytes, SA promoted apoptosis by inducing MKK4 (mitogenactivated protein kinase kinase 4)/SEK1 (stress-activated protein kinase/extracellular-signalregulated kinase kinase-1) and JNK-1/2 (c-Jun N-terminal kinase-1/2) activation. CGS21680 addition prevented JNK-1/2 activation and reduced apoptosis without interfering with lipid accumulation. CGS21680 action required PI3K (phosphoinositide 3-kinase)/Akt-mediated block of MKK4/SEK1. Consistently, PI3K inhibition with wortmannin abolished the cytoprotective action of CGS21680 and reverted MKK4 inhibition. SA lipotoxicity was also prevented by transfecting HTC cells with a specific MKK4/SEK1 siRNA (small interfering RNA). In rats receiving the MCD diet, the development of NASH was associated with MKK4/SEK1 and JNK-1/2 activation. CGS21680 (0.5 mg/kg of body weight, intraperitoneal) administration to MCD-fed rats prevented JNK-1/2 activation by acting on MKK4/SEK1. CGS21680 also effectively reduced NASH-associated ALT (alanine aminotransferase) release, hepatocyte apoptosis, liver inflammation and fibrosis without affecting hepatic steatosis. Taken together, these results demonstrate that, by inhibiting JNK-1/2, A 2a R stimulation reduces lipotoxicity and ameliorates NASH, giving a rationale to investigate A 2a R agonists as possible new therapeutic agents in preventing fatty liver progression to NASH

Role of the co-stimulatory molecule inducible T-cell co-stimulator ligand (ICOSL) in the progression of experimental metabolic dysfunction-associated steatohepatitis

Background and aimsInducible T-cell Co-Stimulator (ICOS) present on T-lymphocytes and its ligand ICOSL expressed by myeloid cells play multiple roles in regulating T-cell functions. However, recent evidence indicates that reverse signalling involving ICOSL is also important in directing the differentiation of monocyte-derived cells. In this study, we investigated the involvement of ICOS/ICOSL dyad in modulating macrophage functions during the evolution of metabolic dysfunction-associated steatohepatitis (MASH).ResultsIn animal models of MASH, ICOS was selectively up-regulated on CD8+ T-cells in parallel with an expansion of ICOSL-expressing macrophages. An increase in circulating soluble ICOSL was also evident in patients with MASH as compared to healthy individuals. ICOSL knockout (ICOSL-/-) mice receiving choline/methionine deficient (MCD) diet for 6 weeks had milder steatohepatitis than wild type mice. MASH improvement was confirmed in mice fed with cholesterol-enriched Western diet for 24 weeks in which ICOSL deficiency greatly reduced liver fibrosis along with the formation of crown-like macrophage aggregates producing the pro-fibrogenic mediators osteopontin (OPN) and galectin-3 (Gal-3). These effects associated with a selective shewing of F4-80+/CD11bhigh monocyte-derived macrophages (MoMFs) expressing the Triggering Receptor Expressed on Myeloid cells 2 (TREM2) to CD11blow/F4-80+ cells positive for the Kupffer cell marker C-type lectin-like type 2 receptor (CLEC-2), thus indicating an increased MoMF maturation toward monocyte-derived Kupffer cells.ConclusionsThese results suggest that CD8+ T-cells interaction with monocyte-derived macrophages through ICOS/ICOSL critically supports a specific subset of TREM2+-expressing cells contributing to the evolution of steatohepatitis. The data also point ICOS/ICOSL dyad as a possible target for therapeutic interventions in MASH

USEFULNESS OF CT COLONOGRAPHY IN PATIENTS WITH OCCLUSIVE COLORECTAL CANCER BEFORE METALLIC STENT PLACEMENT: A SINGLE ENTER EXPERIENCE

Up to 15% of patients with colorectal cancer (CRC) present with large bowel obstruction. Currently, computed tomography colonography (CTC) is regarded as a promising technique for complete evaluation of the proximal colon and simultaneous assessment of extraluminal status. Aim of this retrospective, observational study is to evaluate the feasibility of using CTC for preoperative examination of the proximal colon before metallic stgent placement in patients with colon obstruction caused by CRC. Sixteen patients who demonstrated colonic obstruction caused by CRC, underwent CTC immediately after incomplete colonoscopy. Per-patient sensitivity of CTC for lesion 5 mm larger in diameter in the colon proximal to the stent was 100% (95% CI: 0,4385-1). Per-patients specificity for lesions 5 mm and larger in the proximal colon was 92,3% (95% CI: 6669-0,9863). CTC did not generate any false diagnosis of synchronous cancer. false positive findings at CTC did not result in a change in surgical plan for asny patients. Although the small number of patient of our study, our data show that CTC is a safe and useful method for preoperative examination of the proximal colon before metallic stent placement in patients with acute colon obstruction caused by CRC

Hepatocyte-specific deletion of HIF2&#945; prevents NASH-related liver carcinogenesis by decreasing cancer cell proliferation

Background & aims: Hypoxia and hypoxia-inducible factors (HIFs) are involved in chronic liver disease progression. We previously showed that hepatocyte HIF-2\u3b1 activation contributed significantly to nonalcoholic fatty liver disease progression in experimental animals and human patients. In this study, using an appropriate genetic murine model, we mechanistically investigated the involvement of hepatocyte HIF-2\u3b1 in experimental nonalcoholic steatohepatitis (NASH)-related carcinogenesis. Methods: The role of HIF-2\u3b1 was investigated by morphologic, cellular, and molecular biology approaches in the following: (1) mice carrying hepatocyte-specific deletion of HIF-2\u3b1 (HIF-2\u3b1-/- mice) undergoing a NASH-related protocol of hepatocarcinogenesis; (2) HepG2 cells stably transfected to overexpress HIF-2\u3b1; and (3) liver specimens from NASH patients with hepatocellular carcinoma. Results: Mice carrying hepatocyte-specific deletion of HIF-2\u3b1 (hHIF-2\u3b1-/-) showed a significant decrease in the volume and number of liver tumors compared with wild-type littermates. These effects did not involve HIF-1\u3b1 changes and were associated with a decrease of cell proliferation markers proliferating cell nuclear antigen and Ki67. In both human and rodent nonalcoholic fatty liver disease-related tumors, HIF-2\u3b1 levels were strictly associated with hepatocyte production of SerpinB3, a mediator previously shown to stimulate liver cancer cell proliferation through the Hippo/Yes-associated protein (YAP)/c-Myc pathway. Consistently, we observed positive correlations between the transcripts of HIF-2\u3b1, YAP, and c-Myc in individual hepatocellular carcinoma tumor masses, while HIF-2\u3b1 deletion down-modulated c-Myc and YAP expression without affecting extracellular signal-regulated kinase 1/2, c-Jun N-terminal kinase, and AKT-dependent signaling. In\ua0vitro data confirmed that HIF-2\u3b1 overexpression induced HepG2 cell proliferation through YAP-mediated mechanisms. Conclusions: These results indicate that the activation of HIF-2\u3b1 in hepatocytes has a critical role in liver carcinogenesis during NASH progression, suggesting that HIF-2\u3b1-blocking agents may serve as novel putative therapeutic tools