339 research outputs found
Enzymatic Inactivation of Oxysterols in Breast Tumor Cells Constraints Metastasis Formation by Reprogramming the Metastatic Lung Microenvironment
Recent evidence indicates that immune cells contribute to the formation of tumor metastases by regulating the pre-metastatic niche. Whether tumor-derived factors involved in primary tumor formation play a role in metastasis formation is poorly characterized. Oxysterols act as endogenous regulators of lipid metabolism through the interaction with the nuclear Liver X Receptors-(LXR)alpha and LXR beta. In the context of tumor development, they establish a pro-tumor environment by dampening antitumor immune responses, and by recruiting pro-angiogenic and immunosuppressive neutrophils. However, the ability of LXR/oxysterol axis to promote tumor invasion and metastasis by exploiting immune cells, is still up to debate. In this study we provide evidence that oxysterols participate in the primary growth of orthotopically implanted 4T1 breast tumors by establishing a tumor-promoting microenvironment. Furthermore, we show that oxysterols are involved in the metastatic spread of 4T1 breast tumors, since their enzymatic inactivation mediated by the sulfotransferase 2B1b, reduces the number of metastatic cells in the lungs of tumor-bearing mice. Finally, we provide evidence that oxysterols support the metastatic cascade by modifying the lung metastatic niche, particularly allowing the recruitment of tumor-promoting neutrophils. These results identify a possible new metastatic pathway to target in order to prevent metastasis formation in breast cancer patients
Re-occurrence of the CD20 molecule expression subsequent to CD20-negative relapse in diffuse large B-cell lymphoma.
We report the first case of diffuse large B-cell lymphoma (DLBCL) of the stomach displaying CD20-negative relapse after rituximab-containing treatment and the re-appearance of CD20 expression at the second failure. The loss of CD20 expression in B-cell lymphomas relapsing after rituximab is a well-known phenomenon, but its actual impact in DLBCL is difficult to estimate. This paradigmatic case suggests that CD20-expression reappearance after purging of CD20-positive clones with rituximab might be an underestimated occurrence in B-cell lymphomas. Accordingly, every relapse, whenever possible, should be histologically assessed with diagnostic and immunophenotyping purposes
Ground deformation and source geometry of the 30 October 2016 Mw 6.5 Norcia earthquake (Central Italy) investigated through seismological data, DInSAR measurements, and numerical modelling
We investigate the Mw 6.5 Norcia (Central Italy) earthquake by exploiting seismological data, DInSAR measurements, and a numerical modelling approach. In particular, we first retrieve the vertical component (uplift and subsidence) of the displacements affecting the hangingwall and the footwall blocks of the seismogenic faults identified, at depth, through the hypocenters distribution analysis. To do this, we combine the DInSAR measurements obtained from coseismic SAR data pairs collected by the ALOS-2 sensor from ascending and descending orbits. The achieved vertical deformation map displays three main deformation patterns: (i) a major subsidence that reaches the maximum value of about 98 cm near the epicentral zones nearby the town of Norcia; (ii) two smaller uplift lobes that affect both the hangingwall (reaching maximum values of about 14 cm) and the footwall blocks (reaching maximum values of about 10 cm). Starting from this evidence, we compute the rock volumes affected by uplift and subsidence phenomena, highlighting that those involved by the retrieved subsidence are characterized by significantly higher deformation values than those affected by uplift (about 14 times). In order to provide a possible interpretation of this volumetric asymmetry, we extend our analysis by applying a 2D numerical modelling approach based on the finite element method, implemented in a structural-mechanic framework, and exploiting the available geological and seismological data, and the ground deformation measurements retrieved from the multi-orbit ALOS-2 DInSAR analysis. In this case, we consider two different scenarios: the first one based on a single SW-dipping fault, the latter on a main SW-dipping fault and an antithetic zone. In this context, the model characterized by the occurrence of an antithetic zone presents the retrieved best fit coseismic surface deformation pattern. This result allows us to interpret the subsidence and uplift phenomena caused by the Mw 6.5 Norcia earthquake as the result of the gravitational sliding of the hangingwall along the main fault plane and the frictional force acting in the opposite direction, consistently with the double couple fault plane mechanism
Invariant NKT cells contribute to chronic lymphocytic leukemia surveillance and prognosis
Chronic lymphocytic leukemia (CLL) is characterized by the expansion of malignant CD5(+) B lymphocytes in blood, bone marrow and lymphoid organs. CD1d-restricted invariant Natural Killer T (iNKT) cells are innate-like T lymphocytes strongly implicated in tumor surveillance. We investigated the impact of iNKT cells in the natural history of the disease both in Eμ;-Tcl1 (Tcl1) CLL mouse model and 68 CLL patients. We found that Tcl1-CLL cells express CD1d and iNKT cells critically delay the disease onset, but become functionally impaired upon disease progression. In patients, disease progression correlates also with high CD1d expression on CLL cells and impaired iNKT cells. Conversely, disease stability correlates with negative/low CD1d expression on CLL cells and normal iNKT cells, suggesting an indirect leukemia control. iNKT cells indeed hinder CLL survival in vitro by restraining CD1d-expressing Nurse Like Cells, a relevant pro-leukemia macrophage population. Finally, multivariate analysis identifies iNKT cell frequency as independent predictor of disease progression. Together, these results support iNKT cell contribution to CLL immune-surveillance and highlight iNKT cell frequency as prognostic marker for disease progression
Unbalanced IDO1/IDO2 endothelial expression and skewed keynurenine pathway in the pathogenesis of COVID-19 and post-COVID-19 pneumonia
Despite intense investigation, the pathogenesis of COVID-19 and the newly defined long COVID-19 syndrome are not fully understood. Increasing evidence has been provided of metabolic alterations characterizing this group of disorders, with particular relevance of an activated tryptophan/kynurenine pathway as described in this review. Recent histological studies have documented that, in COVID-19 patients, indoleamine 2,3-dioxygenase (IDO) enzymes are differentially expressed in the pulmonary blood vessels, i.e., IDO1 prevails in early/mild pneumonia and in lung tissues from patients suffering from long COVID-19, whereas IDO2 is predominant in severe/fatal cases. We hypothesize that IDO1 is necessary for a correct control of the vascular tone of pulmonary vessels, and its deficiency in COVID-19 might be related to the syndrome's evolution toward vascular dysfunction. The complexity of this scenario is discussed in light of possible therapeutic manipulations of the tryptophan/kynurenine pathway in COVID-19 and post-acute COVID-19 syndromes
Immunohistochemical evaluation and clinicopathological correlation of Mer and Axl tyrosine kinase TAM receptors in cutaneous melanoma
Background: Malignant melanoma (MM) is potentially the most dangerous form of skin tumor. In the last few years, the so-called TAM receptors, a unique family of tyrosine kinase (TK) receptors,have become increasingly important.
Objectives: To evaluate Mer and Axl TAM receptor expression to find clinicopathological features that could explain the biological behavior of MM.
Patients and Methods: Clinicopathological data were obtained from an MM electronic database at our Institute. We reviewed 24 cutaneous MM specimens. TAM receptor expression was assayed using immunohistochemistry. Combinative semiquantitative scoring was used for the evaluation of TAM receptor expression (MerTK and AxlTK). Appropriate statistical methods were used to evaluate a possible correlation between TAM receptor expression and the clinicopathological variables of the MM samples (univariate analysis and multivariate analysis). Results: MerTK and AxlTK were expressed differently in the MM samples, with a major expression of the first receptor. The cells of the tumor microenvironment contributed to the majority of the total score. A significant association was found between AxlScore and the site of the tumor and between AxlScore and the variable ulceration; another correlation was found between MerScore and the lowing characteristics: pathological stage of the tumor (pT), sex, ulceration, and tumor-infiltrating lymphocytes.
Conclusions: All correlations between the expression of MerTK and AxlTK with the clinical and histological variables of MM should be validated in a large group of people in order to increase the validity and the impact of our observations, with subsequently therapeutic implications in the era of the “targeted therapy.
Absence of Rac1 and Rac3 GTPases in the nervous system hinders thymic, splenic and immune-competence development
The nervous system influences organ development by direct innervation and the action of hormones. We recently showed that the specific absence of Rac1 in neurons (Rac1N) in a Rac3-deficient (Rac3KO) background causes motor behavioural defects, epilepsy, and premature mouse death around postnatal day 13. We report here that Rac1N/Rac3KO mice display a progressive loss of immune-competence. Comparative longitudinal analysis of lymphoid organs from control, single Rac1N or Rac3KO, and double Rac1N/Rac3KO mutant animals showed that thymus development is preserved up to postnatal day 9 in all animals, but is impaired in Rac1N/Rac3KO mice at later times. This is evidenced by a drastic reduction in thymic cell numbers. Cell numbers were also reduced in the spleen, leading to splenic tissue disarray. Organ involution occurs in spite of unaltered thymocyte and lymphocyte subset composition, and proper mature T-cell responses to polyclonal stimuli in vitro. Suboptimal thymus innervation by tau-positive neuronal terminals possibly explains the suboptimal thymic output and arrested thymic development, which is accompanied by higher apoptotic rates. Our results support a role for neuronal Rac1 and Rac3 in dictating proper lymphoid organ development, and suggest the existence of lymphoid-extrinsic mechanisms linking neural defects to the loss of immune-competence
Periostin expression in uninvolved skin as a potential biomarker for rapid cutaneous progression in systemic sclerosis patients: a preliminary explorative study
ObjectivesThis study aimed to evaluate periostin serum levels and skin expression in patients with systemic sclerosis (SSc).MethodsWe enrolled 35 patients with diffuse (d-SSc) or limited (l-SSc) SSc, 15 patients with very early diagnosis of systemic sclerosis (VEDOSS), and 30 sex-matched healthy controls. Periostin serum levels were determined by an enzyme-linked immunosorbent assay (ELISA). Periostin skin expression was determined by immunohistochemistry (IHC) on paired involved and uninvolved 5-mm skin biopsy samples in a subgroup of 10 d-SSc and 10 L-SSc patients. A 12-month follow-up was considered.ResultsWe included 50 patients (mean age 53.1 ± 16.1 years; women 94%; mean disease duration 38.2 ± 45.1 months; anti-centromere 50%; anti-Scl70 40%), 35 of them with a definite SSc (68.8% l-SSc; 31.4% d-SSc; mean mRSS 9.0 ± 7.2) and 15 with VEDOSS; 30 controls were also included in this study. Periostin serum levels were higher in SSc patients compared to controls (32.7 ± 8.0 ng/mL vs. 27.7 ± 7.3 ng/mL; p < 0.001), while these levels were comparable among different groups of patients (29.7 ± 6.9 ng/mL in VEDOSS, 33.4 ± 7.8 ng/mL in lc-SSc; and 34.0 ± 8.5 in dc-SSc; p = ns). SSc patients with digital ulcers had higher periostin serum levels (36.2 ± 7.9 ng/mL vs. 30.6 ± 7.3 ng/mL, p < 0.02). Samples from the involved skin of l-SSc and d-SSc patients showed a significant dermal expression of periostin; an identical periostin expression was evident in the uninvolved skin of patients with d-SSc. In 7 out of 10 L-SSc patients, periostin expression was absent on uninvolved skin. In the remaining three l-SSc patients, a mild periostin expression on IHC was detectable on uninvolved skin and all of these three l-SSc patients presented a dramatic skin progression.ConclusionPeriostin skin expression may be a useful biomarker to indicate the presence of a disease at a higher risk of rapid cutaneous involvement
Extrafoveal Müller cells detection in vivo in the human retina: A pilot study based on optical coherence tomography.
Abstract Muller cells (MC) represent a key element for the metabolic and functional regulation of the vertebrate retina. The aim of the present study was to test the feasibility of a new method for the in-vivo detection and quantification of extrafoveal MC in human retina. We developed a new approach to isolate and analyse extrafoveal MC in vivo, starting from structural optical coherence tomography data. Our pilot investigation was based on the optical properties of MC, which are known to not interfere with the light reaching the outer retinal structures. We reconstructed MC in the macular region of 18 healthy subjects and the quantitative analyses revealed ~42,000/9 mm2 cells detected. Furthermore, we included 2 patients affected by peripheral intraocular melanoma, with macular sparing, needing surgical enucleation. We used these two eyes to perform a qualitative comparison between our reconstructions and histological findings. Our study represents the first pilot investigation dedicated on the non-invasive isolation and quantification of MC, in-vivo, in human retina. Although we are aware that our study has several limitations, first of all related with the proper detection of foveal MC, because of the peculiar z-shape morphology, this approach may open new opportunities for the non-invasive in vivo analysis of MC, providing also potential useful perspectives in retinal diseases
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