Giacomo Dell'Antonio

Pancreatic cancers require autophagy for tumor growth

Macroautophagy (autophagy) is a regulated catabolic pathway to degrade cellular organelles and macromolecules. The role of autophagy in cancer is complex and may differ depending on tumor type or context. Here we show that pancreatic cancers have a distinct dependence on autophagy. Pancreatic cancer primary tumors and cell lines show elevated autophagy under basal conditions. Genetic or pharmacologic inhibition of autophagy leads to increased reactive oxygen species, elevated DNA damage, and a metabolic defect leading to decreased mitochondrial oxidative phosphorylation. Together, these ultimately result in significant growth suppression of pancreatic cancer cells in vitro. Most importantly, inhibition of autophagy by genetic means or chloroquine treatment leads to robust tumor regression and prolonged survival in pancreatic cancer xenografts and genetic mouse models. These results suggest that, unlike in other cancers where autophagy inhibition may synergize with chemotherapy or targeted agents by preventing the up-regulation of autophagy as a reactive survival mechanism, autophagy is actually required for tumorigenic growth of pancreatic cancers de novo, and drugs that inactivate this process may have a unique clinical utility in treating pancreatic cancers and other malignancies with a similar dependence on autophagy. As chloroquine and its derivatives are potent inhibitors of autophagy and have been used safely in human patients for decades for a variety of purposes, these results are immediately translatable to the treatment of pancreatic cancer patients, and provide a much needed, novel vantage point of attack.

PTX3 in small‐vessel vasculitides: An independent indicator of disease activity produced at sites of inflammation

OBJECTIVE To verify whether the prototypical long pentraxin PTX3 represents an indicator of the activity of small-vessel vasculitis. METHODS Concentrations of PTX3, a pentraxin induced in endothelium by cytokines, were measured by enzyme-linked immunosorbent assay in the sera of 43 patients with Churg-Strauss syndrome, Wegeners granulomatosis, and microscopic polyangiitis. PTX3 was also measured in the sera of 28 patients with systemic lupus erythematosus (SLE), 22 with rheumatoid arthritis, and 16 with CREST syndrome (calcinosis, Raynauds phenomenon, esophageal dysmotility, sclerodactyly, telangiectasias). Serum concentrations of C-reactive protein (CRP) were measured by immunoturbidimetry. The cells involved in PTX3 production in vivo were identified in skin biopsy samples. RESULTS Patients with active vasculitis had significantly higher concentrations of PTX3 than did those with quiescent disease (P < 0.001). PTX3 levels in the latter group were similar to those in healthy controls. PTX3 levels were higher in patients with untreated vasculitis and lower in patients who underwent immunosuppressive treatments (P < 0.005). In contrast, patients with active SLE had negligible levels of the pentraxin. PTX3 levels did not correlate with CRP levels in vasculitis patients. Endothelial cells produced PTX3 in active skin lesions. CONCLUSION PTX3 represents a novel acute-phase reactant produced at sites of active vasculitis.

Common noncoding UMOD gene variants induce salt-sensitive hypertension and kidney damage by increasing uromodulin expression

Hypertension and chronic kidney disease (CKD) are complex traits representing major global health problems. Multiple genome-wide association studies have identified common variants in the promoter of the UMOD gene, which encodes uromodulin, the major protein secreted in normal urine, that cause independent susceptibility to CKD and hypertension. Despite compelling genetic evidence for the association between UMOD risk variants and disease susceptibility in the general population, the underlying biological mechanism is not understood. Here, we demonstrate that UMOD risk variants increased UMOD expression in vitro and in vivo. Uromodulin overexpression in transgenic mice led to salt-sensitive hypertension and to the presence of age-dependent renal lesions similar to those observed in elderly individuals homozygous for UMOD promoter risk variants. The link between uromodulin and hypertension is due to activation of the renal sodium cotransporter NKCC2. We demonstrated the relevance of this mechanism in humans by showing that pharmacological inhibition of NKCC2 was more effective in lowering blood pressure in hypertensive patients who are homozygous for UMOD promoter risk variants than in other hypertensive patients. Our findings link genetic susceptibility to hypertension and CKD to the level of uromodulin expression and uromodulins effect on salt reabsorption in the kidney. These findings point to uromodulin as a therapeutic target for lowering blood pressure and preserving renal function.

Antinociceptive effect of a new P2Z/P2X7 antagonist, oxidized ATP, in arthritic rats

The neurotransmitter adenosine triphosphate (ATP) is released from sensory nerve endings during inflammation and acts at the level of P2X receptors. We used the irreversible inhibitor of P2z/P2X7 receptor, designated oxidized ATP (oATP), to test its possible antinociceptive activity in arthritic rats. We induced unilateral inflammation of the rat hind paw by local injection of Freunds complete adjuvant. Administration of the adjuvant resulted in a significant reduction of paw pressure threshold (PPT). Injection of oATP into inflamed paws significantly increased, in a dose-dependent manner, PPT values to levels comparable with or higher than those evaluated in control uninflamed paws. The data indicate that the P2z/P2X7 receptor system exerts a role in nociception and that oATP, by inhibiting such a receptor, reduces the nociceptive signal in the course of peripheral inflammation.

Plasma and tissue expression of the long pentraxin 3 during normal pregnancy and preeclampsia

OBJECTIVE: Cell death normally occurs during pregnancy and is critical during its common complication, preeclampsia. The long pentraxin 3 (PTX3) gene is generated in tissues that cope with excessive or deregulated cell death and inhibits the cross-presentation of cell-associated antigens. We examined whether PTX3 is expressed during pregnancy and possibly involved in the development of preeclampsia. METHODS: Women with preeclampsia (n = 30), women with uncomplicated pregnancies (n = 66), age-matched healthy women (n = 50), women who developed acute bacterial infections (n = 20), and women with rheumatoid arthritis (n = 20) were studied. The concentrations of PTX3 were measured in the blood by a sandwich enzyme-linked immunosorbent assay (ELISA) and in placentas by immunohistochemistry. The concentrations of PTX3 and C-reactive protein in the various groups were compared by nonparametric tests (the Mann-Whitney U and the Kruskal-Wallis tests). The odds of developing preeclampsia were assessed using logistic regression. RESULTS: PTX3 was expressed in amniotic epithelium and chorionic mesoderm, trophoblast terminal villi, and perivascular stroma in placentas from pregnancies of uncomplicated subjects. Circulating levels steadily rose during normal gestation and peaked during labor. Serum levels of PTX3 were strikingly higher in preeclampsia compared with normal control pregnancies (5.08 ± 1.34 and 0.59 ± 0.07 ng/mL, respectively, P < .001). Sites of higher expression in the placentas from preeclamptic patients include infarcts and fibrinoid zones. CONCLUSION: Defects in the homeostatic response to cell death/remodeling events, revealed by enhanced levels of PTX3, could be implicated in preeclampsia. LEVEL OF EVIDENCE: II-2

Selective up-regulation of the soluble pattern-recognition receptor pentraxin 3 and of vascular endothelial growth factor in giant cell arteritis: relevance for recent optic nerve ischemia.

OBJECTIVE To assess local expression and plasma levels of pentraxin 3 (PTX3) in patients with giant cell arteritis (GCA). METHODS Plasma and serum samples were obtained from 75 patients with GCA (20 of whom had experienced optic nerve ischemia in the previous 3 weeks and 24 of whom had experienced symptom onset in the previous 6 months and had no history of optic nerve ischemia) and 63 controls (35 age-matched healthy subjects, 15 patients with rheumatoid arthritis, and 13 patients with chronic stable angina). In 9 patients in whom GCA was recently diagnosed, circulating levels of interleukin-1β (IL-1β), IL-2, IL-4, IL-6, IL-7, IL-8, IL-10, IL-12p70, CCL2/monocyte chemotactic protein 1, CCL3/macrophage inflammatory protein 1α (MIP-1α), CCL4/MIP-1β, CCL11/eotaxin, CXCL9/monokine induced by interferon-γ, CXCL10/interferon-γ-inducible 10-kd protein, tumor necrosis factor α (TNFα), interferon-γ, vascular endothelial growth factor (VEGF), granulocyte-macrophage colony-stimulating factor, and FasL were measured via a multiplexed cytometric assay. PTX3 and VEGF concentrations were assessed by enzyme-linked immunosorbent assay. PTX3 and CD68 expression were determined by immunohistochemistry and immunofluorescence on temporal artery samples. RESULTS GCA patients with very recent optic nerve ischemia had significantly higher PTX3 and VEGF levels compared to other GCA patients and controls. GCA patients with a disease duration of <6 months had significantly higher PTX3 levels compared to other GCA patients and controls. Immunohistochemistry revealed selective PTX3 expression in the wall of inflamed arteries. CONCLUSION Our findings indicate that local expression of PTX3 is a feature of vascular inflammation in GCA; elevated circulating levels of PTX3 identify patients with very recent optic nerve ischemia or a recent diagnosis. Optic nerve ischemia is also associated with increased circulating VEGF levels.

Cancer Arising After Pancreas and/or Kidney Transplantation in a Series of 99 Diabetic Patients

OBJECTIVE Recipients of solid organ transplants have an increased risk of developing certain types of malignancies as compared with the general population. The majority of the literature has reported on neoplasms in kidney and heart transplant recipients. RESEARCH DESIGN AND METHODS We describe 9 neoplasms occurring in 7 out of 73 IDDM patients after simultaneous pancreas and kidney transplantation. No cases were recorded among 26 IDDM recipients of kidney transplantation. RESULTS Among the neoplasms found were 2 cases of posttransplant lymphoproliferative disorder (PTLD), malignant melanoma, basal-cell and squamous-cell carcinoma of the skin in the same patient, squamous-cell carcinoma in situ of the vulva, hepatocarcinoma, small-cell lung cancer, and ductal carcinoma of the breast. Four patients died. Among immunological risk factors, over-immunosuppression for steroid-resistant kidney rejection was administered only in the 2 cases of PTLD. CONCLUSIONS Increased dosage of immunosuppressive agents may be necessary in some patients of prevent or treat rejection in view of their reduced survival on hemodialysis.

Stem Cells and the Kidney: A New Therapeutic Tool?

In the past few years, a number of studies have shown that stem cells can be found in virtually every organ of the adult organism. The kidney is not an exception, and resident stem cells have been identified both in the papilla and along the tubules. Of interest, kidney-bound stem cells have been identified also in the bone marrow. When injected, both resident and bone marrow-derived stem cells are able to reach the injured renal tissue and, once there, to differentiate into renal cells. The evidence that, in humans, some of the acute and most of the chronic renal damages lead to ESRD suggests that in normal conditions, the reservoir of stem cells (considering both resident and bone marrow-derived stem cells) is insufficient to allow a major renal regeneration. Probably the number of stem cells that are ready to intervene in an adult kidney are sufficient to compensate for the normal cell turnover but largely inadequate to counteract a major injury. This is confirmed further by the finding that, even by transplanting a syngenic bone marrow in rats with ablation of 5/6 of the renal function, it is not possible to increase the life expectancy of the animals. Altogether, this evidence suggests that, to clarify the potentiality of a stem cell therapy for renal diseases, experiments that aim to clarify the ideal concentration of stem cells to be injected and to identify the best way of administration are needed.

Inhibition of chemokine expression in rat inflamed paws by systemic use of the antihyperalgesic oxidized ATP

BackgroundWe previously showed that local use of periodate oxidized ATP (oATP, a selective inhibitor of P2X7 receptors for ATP) in rat paw treated with Freunds adjuvant induced a significant reduction of hyperalgesia Herein we investigate the role of oATP, in the rat paws inflamed by carrageenan, which mimics acute inflammation in humans.ResultsLocal, oral or intravenous administration of a single dose of oATP significantly reduced thermal hyperalgesia in hind paws of rats for 24 hours, and such effect was greater than that induced by diclofenac or indomethacin. Following oATP treatment, the expression of the pro-inflammatory chemokines interferon-gamma-inducible protein-10 (IP-10), mon ocyte chemoattractant protein-1 (MCP-1) and interleukin-8 (IL-8) within the inflamed tissues markedly decreased on vessels and infiltrated cells. In parallel, the immunohistochemical findings showed an impairment, with respect to the untreated rats, in P2X7 expression, mainly on nerves and vessels close to the site of inflammation. Finally, oATP treatment significantly reduced the presence of infiltrating inflammatory macrophages in the paw tissue.ConclusionTaken together these results clearly show that oATP reduces carrageenan-induced inflammation in rats.

High blood levels of chromogranin A in giant cell arteritis identify patients refractory to corticosteroid treatment

Giant cell arteritis (GCA) rapidly responds to high-dose corticosteroids. However, smouldering arterial inflammation can persist despite the absence of symptoms and altered acute phase reactants. In patients that are refractory, symptoms relapse during steroid tapering and vascular complications may develop. The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level are not sensitive enough markers to detect refractory disease.1 The neuroendocrine system regulates innate and acquired immune responses, influencing cytokine synthesis and limiting tissue damage via release of neurotransmitters and peptides in peripheral tissues. Chromogranin A in particular is a candidate marker linking neurogenic inflammation and vascular inflammation.2 We investigated by ELISA, as described previously,3 the …