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Psoriasis is a chronic inflammatory skin disease with an autoimmune component and associated with joint inflammation in up to 30% of cases. To investigate autoreactive T cells, we developed an imiquimod-induced psoriasis-like inflammation model in K5-mOVA.tg C57BL/6 mice expressing ovalbumin (OVA) on the keratinocyte membrane, adoptively transferred with OT-I OVA-specific CD8+ T cells. We evaluated the expansion of OT-I CD8+ T cells and their localization in skin, blood, and spleen. scRNA-seq and TCR sequencing data from patients with psoriatic arthritis were also analyzed. In the imiquimod-treated K5-mOVA.tg mouse model, OT-I T cells were markedly expanded in the skin and blood at early time points. OT-I T cells in the skin showed mainly CXCR3+ effector memory phenotype, whereas in peripheral blood there was an expansion of CCR4+CXCR3+ OT-I cells. At a later time point, expanded OVA-specific T-cell population was found in the spleen. In patients with psoriatic arthritis, scRNA-seq and TCR sequencing data showed clonal expansion of CCR4+ TCM cells in the circulation and further expansion in the synovial fluid. Importantly, there was a clonotype overlap between CCR4+ TCM in the peripheral blood and CD8+ T-cell effectors in the synovial fluid. This mechanism could play a role in the generation and spreading of autoreactive T cells to the synovioentheseal tissues in psoriasis patients at risk of developing psoriatic arthritis.

Reactive oxygen species (ROS) act as signal molecules in several biological processes whereas excessive, unregulated, ROS production contributes to the development of pathological conditions including endothelial dysfunction and atherosclerosis. The maintenance of a healthy endothelium depends on many factors and on their reciprocal interactions; in this framework, the Notch pathway and shear stress (SS) play two lead roles. Recently, evidence of a crosstalk between ROS, Notch, and SS, is emerging. The aim of this review is to describe the way ROS interact with the Notch pathway and SS protecting from-or promoting-the development of endothelial dysfunction. © 2017 BioFactors, 43(4):475-485, 2017.

It is unknown whether components present in heart failure (HF) patients' serum provide an angiogenic stimulus. We sought to determine whether serum from HF patients affects angiogenesis and its major modulator, the Notch pathway, in human umbilical vein endothelial cells (HUVECs). In cells treated with serum from healthy subjects or from patients at different HF stage we determined: (1) Sprouting angiogenesis, by measuring cells network (closed tubes) in collagen gel. (2) Protein levels of Notch receptors 1, 2, 4, and ligands Jagged1, Delta-like4. We found a higher number of closed tubes in HUVECs treated with advanced HF patients serum in comparison with cells treated with serum from mild HF patients or controls. Furthermore, as indicated by the reduction of the active form of Notch4 (N4IC) and of Jagged1, advanced HF patients serum inhibited Notch signalling in HUVECs in comparison with mild HF patients' serum and controls. The circulating levels of NT-proBNP (N-terminal of the pro-hormone brain natriuretic peptide), a marker for the detection and evalutation of HF, were positively correlated with the number of closed tubes (r = 0.485) and negatively with Notch4IC and Jagged1 levels in sera-treated cells (r = -0.526 and r = -0.604, respectively). In conclusion, we found that sera from advanced HF patients promote sprouting angiogenesis and dysregulate Notch signaling in HUVECs. Our study provides in vitro evidence of an angiogenic stimulus arising during HF progression and suggests a role for the Notch pathway in it. J. Cell. Physiol. 231: 2700-2710, 2016. © 2016 Wiley Periodicals, Inc.

The small molecule inhibitor of the MDM2/p53 interaction Nutlin-3 is a promising anti-cancer agent, which exhibits activity against a variety of cancers, including acute myeloid leukemia (AML). Previous studies have shown that Nutlin-3 variably induces apoptosis and cell cycle arrest in cancer cells while it shows low/absent cytotoxicity in normal cells. However, the reason for the selective pro-apoptotic activity in cancer cells with respect to normal counterparts is incompletely understood. In this study, we have compared the induction of several known target genes of p53 in two p53(wild-type) AML cell lines, OCI-AML3 and MOLM, in comparison with primary normal peripheral blood mononuclear cells (PBMC). Among several p53-target genes activated both in AML cell lines and normal PBMC (BBC3, BAX, MDM2, FAS, CDKN1A, GDF15, GADD45A, TNFRSF10B, TP53I3/PIG3), only TP53I3/PIG3 was selectively activated in MOLM and OCI-AML3, but not in PBMC. The important role of TP53I3/PIG3 in mediating the apoptotic activity of Nutlin-3 was underlined by knock-down experiments with siRNA specific for TP53I3/PIG3, which resulted in a significant decrease in the pro-apoptotic activity of Nutlin-3.

It has been clearly established that receptor activator of nuclear factor kappa B ligand (RANKL) is a key cytokine involved in the differentiation of osteoclastic precursors of the monocytic/macrophagic lineage. However, relatively little information is available on the ability of RANKL to modulate the expression of genes controlling cell survival/apoptosis and proliferation in human osteoclastic cells in comparison to macrophages. For this purpose, CD14+ human peripheral blood mononuclear cells, which express the cognate high affinity receptor activator of nuclear factor kappa B (RANK), were differentiated along the macrophagic or osteoclastic lineage by adding macrophage-colony stimulating factor (M-CSF) or M-CSF plus RANKL in culture for 12 days. RANKL up-regulated the expression of the chemokine MIP1α, which potentiates osteoclastic differentiation and simultaneously activated both anti-apoptotic (Bcl-2) and pro-apoptotic (CIDEB, PYCARD, and BAK-1) genes. Moreover, RANKL markedly up-regulated cylin D2, while it significantly decreased the levels of cyclin A, cyclin-dependent kinase 2, and other cyclin-dependent kinases, in keeping with the notion that end-stage osteoclasts are nondividing cells. Finally, a long-term exposure of RANKL up-regulated the adaptor protein TRAF3 but not TRAF6. Anat Rec, 2007. © 2007 Wiley-Liss, Inc.

Among 14 peripheral blood samples obtained from patients affected by B chronic lymphocytic leukemia (B-CLL) at initial stages (Rai 0–1) of the disease, 6 showed intermediate/high levels of Zap-70 while 8 displayed low/absent levels of Zap-70. Although Zap-70high and Zap-70low B-CLL samples displayed similar levels of surface death receptor TRAIL-R2, recombinant TRAIL induced cytotoxicity only in a subset of Zap-70low B-CLL samples while Zap-70high were completely resistant to TRAIL. The gene expression profiling was next analyzed in all B-CLL samples treated with either chlorambucil or recombinant TRAIL. While chlorambucil up-regulated the steady-state mRNA levels of known p53 target genes, such as PUMA, Fas/CD95 and MDM2 in all B-CLL samples examined, it significantly down-regulated survivin in Zap-70low but not in Zap-70high. On the other hand, recombinant TRAIL up-regulated the expression of several cytokines (IL-1β, IL-1α, IL-8), which have been involved in promoting B-CLL cell survival. In particular, TRAIL selectively up-regulated IL-1β in Zap-70low B-CLL samples, while it markedly and selectively up-regulated its own mRNA and that of cyclooxigenase-2 (COX-2) in Zap-70high. Taken together, our findings suggest that a significant expression of Zap-70 modulate the response of B-CLL to TRAIL, which might represents an initial step in the pathogenesis of B-CLL. J. Cell. Physiol. 213: 229–236, 2007. © 2007 Wiley-Liss, Inc.

Stromal derived factor-1α (SDF-1α), the high-affinity ligand of CXC-chemokine receptor 4 (CXCR4), was added to human CD34+ hematopoietic progenitor cells that can be induced to differentiate along the monocytic or megakaryocytic lineages. In control liquid cell cultures supplemented with two different cytokine cocktails: stem cell factor (SCF), interleukin-3 (IL-3), macrophage-colony stimulating factor (M-CSF), and 10% fetal calf serum (FCS), or, SCF and thrombopoietin (TPO), the expression of surface CXCR4 progressively increased in both the CD14+ monocytic and CD41+ megakaryocytic lineages. While SDF-1α caused only modest effects on cells of the monocytic lineage, it induced profound down-regulation of CXCR4 in megakaryocytic cells at all stages of differentiation. Moreover, while SDF-1α initially up-regulated the early megakaryocytic antigen CD41, at later time points (days 12–16) it induced down-regulation of the late megakaryocytic antigen CD42b. Consistently, at day 16, the number of mature megakaryocytes was significantly decreased in cultures supplemented with SDF-1α. These findings indicate that, besides its primary role in regulating the retention of precursor cells in hematopoietic tissues, the SDF-1α/CXCR4 system participates in the regulation of megakaryocytic development by stimulating the formation of immature megakaryoblasts and inhibiting the formation of mature megakaryocytes. Anat Rec 260:141–147, 2000. © 2000 Wiley-Liss, Inc.

Dear Editor: It has been extensively documented that osteoprotegerin (OPG), a soluble member of the TNF receptor superfamily, inhibits osteoclastogenesis by binding to receptor activator of NF-kB ligand (RANKL) and preventing interaction with its cognate transmembrane receptor RANK [reviewed in 1]. However, OPG can also interact with, and neutralize, TNF-related apoptosis inducing ligand (TRAIL), whose extracellular domain shares a 30% homology with the extracellular domain of RANKL [reviewed in 2]. Although some inconsistencies on the differential binding affinity of OPG for RANKL versus TRAIL were present in initial studies [2, 3], it has been recently demonstrated that the affinity of native OPG for native TRAIL is comparable to that for RANKL (45 nM versus 23 nM, respectively) at 37°C, as determined by plasmon surface resonance analysis [4]. Consistently with this biochemical study, OPG has been shown to act in a paracrine and autocrine manner by binding TRAIL and promoting the survival of multiple myeloma [5], prostate cancer [6], ameloblastoma cells [7] and synovial fibroblasts [8]. Interestingly, previous data from different groups have shown that recombinant TRAIL modulates the differentiation of erythroid and myeloid precursors [9–10], while inhibits both human and mouse osteoclastogenesis when added to pre-osteoclast cultures induced to differentiate with recombinant macrophage colony-stimulating factor (M-CSF) +RANKL as well as to mature osteoclasts [11–14]. On the other hand, a couple of studies suggested that recombinant soluble TRAIL might promote osteoclastogenesis [4, 15], and the proposed molecular mechanism to explain such observation was a competition between TRAIL and RANKL for OPG binding. However, it should be noticed that Vitovsky et al. used much higher concentrations of TRAIL (500 ng/ml) than RANKL (30 ng/ml) or OPG (50 ng/ml) and more importantly used mouse bone marrow pre-osteoclasts [4]. In this respect, it has been clearly shown that mouse pre-osteoclasts only express TRAIL-R2 [2], while human peripheral blood-derived pre-osteoclasts express both death receptors TRAIL-R1 and TRAIL-R2 as well as TRAIL-R4 [11–14]. Therefore, to further elucidate the important issue of the interplay between RANKL, TRAIL and OPG in human osteoclastogenesis, we have cultured adherent PBMC with M-CSF+RANKL for 14 days in the absence or presence of recombinant OPG and recombinant TRAIL, prepared as previously described [16]. TRAIL and OPG were added alone or in combination. Importantly, all cytokines were used at the same concentration (50 ng/ml). As expected [11–14], the addition of TRAIL to M-CSF+RANKL significantly (P < 0.05) inhibited osteoclast formation (Fig. 1A and B). Of note, recombinant OPG completely abrograted (P < 0.05) osteoclast formation irrespectively of the presence of recombinant TRAIL in culture (Fig. 1A and B). The anti-osteoclastic activity of OPG could not be ascribed to a low affinity of OPG for TRAIL since OPG (50 ng/ml) efficiently inhibited the apoptosis induced by TRAIL (50 ng/ml) in HL-60 leukemic cells (data not shown). 1 Effect of combined treatment of RANKL, TRAIL and OPG on osteoclastic differentiation. Adherent PBMC were cultured with M-CSF alone for 6 days. Then cells were cultured for additional 14 days with the addition of RANKL in the absence or presence of TRAIL ... Our current observations on one hand confirm that TRAIL has anti-osteoclastic activity and on the other hand indicate that it does not affect the potent anti-osteoclastic activity of OPG at least in the simplified model of osteoclastogenesis represented by human PBMC induced to differentiate by M-CSF+RANKL. Taken together with previous studies [4, 11–15], these data also suggest that the relative concentrations of TRAIL, RANKL and OPG in the local microenvironment are likely key determinant for the regulation of osteoclastogenesis.

The cytopathic effects (CPE) resulting from the infection of CD4+ T cells by human herpes-virus 7 (HHV-7) comprises two major mechanisms: generation of large polyploid cells, which eventually undergo necrotic lysis, and apoptosis, predominantly occurring in small mononucleated cells. To dissect the relative contribution of these two phenomena to the overall cytopathicity of HHV-7 in vitro, we have investigated the effect of acute HHV-7 infection on SupT1 CD4+ T cell lines stably transfected either with the bcl-2 anti-apoptotic gene or with the control vector. Overexpression of Bcl-2 protein by these cells was associated with a progressive decline of the total number of viable cells, and a relative increase of enlarged polyploid cell. Of note, the size of polyploid cells was significantly greater in SupT1 cells over expressing bcl-2 than in cells transfected with the control vector. In addition, bcl-2 expression accelerated the kinetics of an acute spreading of HHV-7 infection, as determined by HHV-7-specific indirect immunostaining revealed by either fluorescence microscopy or flow cytometry. Our results indicate that inhibition of apoptosis in HHV-7-infected cultures greatly favors the process of polyploidization and represents a major mechanism to maximize viral transmission.

The effect of differentiating doses of all-trans retinoic acid (ATRA, 10−6 m) and vitamin D3 (10−7 m) was investigated on the nuclear levels of endogenous ceramide and protein kinase C-ζ (PKC-ζ) catalytic activity in HL-60 myeloid cells. ATRA induced a parallel increase of ceramide and catalytically active PKC-ζ into the nuclear compartment of HL-60 cells (peak at 72 h). On the other hand, vitamin D3 increased the levels of nuclear ceramide and PKC-ζ activity to a lesser extent and with a delayed kinetics compared to ATRA (peak at 96 h). Pretreatment of HL-60 cells with high pharmacological concentrations of exogenously-added C2-ceramide (10−6 m) completely blocked the ATRA-mediated activation of nuclear PKC-ζ. Exogenous C2-ceramide (10−6 m) also inhibited the granulocytic differentiation induced by ATRA, whereas it did not affect monocytic differentiation mediated by vitamin D3. Transient transfection experiments performed with a plasmid construct containing a constitutively active mutated form of the PKC-ζ cDNA fused in 3′ to a fluorescent tag protein (pEGFP-PKC-ζ) demonstrated that the overexpression of catalytically active PKC-ζ was not accompanied by the appearance of a differentiated morphology. These findings suggest that nuclear PKC-ζ is necessary but not sufficient to induce granulocytic differentiation of HL-60 myeloid malignant cells.

We have analyzed by PCR skin lesions from classic, endemic and AIDS-related Kaposi's sarcoma (KS), as well as from KS-derived cell lines, the presence of ubiquitous transforming viruses. BK virus (BKV), a transforming human papovavirus which has been associated with human tumors, was detected in 100% of KS skin lesions and 75% of KS cell lines. KS specimens contained a full-length, intact BKV early region, but minor rearrangements were observed in some tumors. BKV was also detected with a high prevalence (57-67%) in genital tissues and sperm, thus fulfilling the role of a sexually transmitted agent in KS. The closely related JC virus (JCV), which has never been associated with human malignancies, was present in 11-20% of KS specimens and was detected with a low prevalence (0-21%) in genital tissues and sperm. Simian virus 40 (SV40) was not detected in any KS lesions. Herpes simplex virus (HSV) DNA sequences were detected in 20-25% of KS lesions. Malignant human papillomavirus (HPV) types 16 and 18 and benign HPV types 6 and 11 were detected in KS specimens with a similar prevalence of 11-83%, suggesting that the presence of HPV-transforming sequences is not a specific trait of HPV interaction with KS tissue. Furthermore, JCV, SV40, HSV and HPV DNA sequences were not detected in KS cell lines, suggesting that these viruses are not associated to KS neoplastic cells in KS tissue. KS cell lines were also negative for DNA sequences of KS-HV, the novel herpesvirus detected in primary KS lesions. The constant association of BKV DNA with KS lesions and KS cell lines suggests that BKV-transforming functions may participate in the development of KS.

Little is known on the ability of different epithelia to release soluble TNF-related apoptosis-inducing ligand (TRAIL) and the relevance of TRAIL secretion by epithelial cells is still incompletely understood. On these bases, we have measured the concentration of soluble TRAIL by ELISA in the conjunctival sac fluid. It was the highest ever detected in a biological fluid (mean value of 26,800 pg/ml), being approximately 20-fold greater than that found in human saliva and >200-fold greater than that detected in human serum. On the other hand, osteoprotegerin, the soluble decoy receptor of TRAIL, was almost undetectable in the conjunctival sac fluid. Of note, the levels of soluble TRAIL measured in conjunctival sac fluid were in the range able to induce in vitro apoptosis of lymphoma cells. By in situ immunohistochemistry, TRAIL protein expression was predominantly detected in the corneal epithelium and, to a less extent, in the conjunctival epithelium. By flow cytometry analysis, membrane-associated TRAIL was documented in isolated corneal epithelial cells obtained from patients undergoing photorefractive keratectomy (PRK). The key contribution provided by corneal epithelium to the production of soluble TRAIL was underscored in time-course experiments, in which a marked decrease of the levels of soluble TRAIL in the conjunctival sac fluid was demonstrated 1 day after PRK followed by a progressive recovery at days 5–30 after PRK. Taken together, our findings strongly support a major role of soluble TRAIL in protecting cornea and conjunctiva from tumor formation and/or invasion. J. Cell. Physiol. 218: 199–204, 2009. © 2008 Wiley-Liss, Inc.