Influencia de la neoateroesclerosis en el pronóstico y la respuesta al tratamiento de los pacientes con reestenosis en el stent

Introduction and objectivesNeoatherosclerosis is one of the causes of in-stent restenosis (ISR). Our objective was to evaluate the influence of neoatherosclerosis on prognosis and treatment response in patients with ISR.MethodsThis is a pooled analysis of the optical coherence tomography (OCT)-substudies of 2 multicenter, randomized clinical trials, RIBS IV and V, comparing treatment with paclitaxel-coated balloon vs everolimus-eluting stent in patients with ISR. OCT evaluation was performed at baseline and at 6 to 9 months. Neoatherosclerosis was defined in baseline OCT as neointima with calcified or lipid content. We evaluated the angiographic and OCT results at 6 to 9 months and the occurrence of major adverse cardiovascular events at 3 years of follow-up in patients with and without neoatherosclerosis treated with paclitaxel-coated balloon or everolimus-eluting stents.ResultsSixty-four patients underwent OCT at the time of the index procedure. Neoatherosclerosis was documented in 23 (36%) lesions. Angiographic follow-up at 6 to 9 months showed no differences in restenosis [5 (24%) vs 6 (15%) P = .49], minimum lumen diameter (1.79 ± 0.7 vs 1.94 ± 0.6 mm; P = .41) or late loss (0.33 ± 0.7 vs 0.15 ± 0.5; P = .34) in patients with and without neoatherosclerosis, respectively. Follow-up OCT confirmed the absence of differences in quantitative parameters and the characteristics of tissue coverage between the 2 groups. At 3 years of follow-up, the major adverse cardiovascular events rate was 3 (13%) vs 5 (12%) in the neoatherosclerosis and nonneoatherosclerosis groups (HR, 0.94; 95%CI, 0.22-3.93; P = .93).ConclusionsIn this limited study population, OCT-defined neoatherosclerosis did not seem to influence acute and long-term outcomes in patients randomized to paclitaxel-coated balloon or everolimus-eluting stents for ISR.     

Pharmacological doses of melatonin impede cognitive decline in tau‐related Alzheimer models,once tauopathy is initiated,by restoring the autophagic flux

Alterations in autophagy are increasingly being recognized in the pathogenesis of proteinopathies like Alzheimer's disease (AD). This study was conducted to evaluate whether melatonin treatment could provide beneficial effects in an Alzheimer model related to tauopathy by improving the autophagic flux and, thereby, prevent cognitive decline. The injection of AAV‐hTau^P301L viral vectors and treatment/injection with okadaic acid were used to achieve mouse and human ex vivo, and in vivo tau‐related models. Melatonin (10 μmol/L) impeded oxidative stress, tau hyperphosphorylation, and cell death by restoring autophagy flux in the ex vivo models. In the in vivo studies, intracerebroventricular injection of AAV‐hTau^P301L increased oxidative stress, neuroinflammation, and tau hyperphosphorylation in the hippocampus 7 days after the injection, without inducing cognitive impairment; however, when animals were maintained for 28 days, cognitive decline was apparent. Interestingly, late melatonin treatment (10 mg/kg), starting once the alterations mentioned above were established (from day 7 to day 28), reduced oxidative stress, neuroinflammation, tau hyperphosphorylation, and caspase‐3 activation; these observations correlated with restoration of the autophagy flux and memory improvement. This study highlights the importance of autophagic dysregulation in tauopathy and how administration of pharmacological doses of melatonin, once tauopathy is initiated, can restore the autophagy flux, reduce proteinopathy, and prevent cognitive decline. We therefore propose exogenous melatonin supplementation or the development of melatonin derivatives to improve autophagy flux for the treatment of proteinopathies like AD.     

Disease severity and treatment requirements in familial inflammatory bowel disease

Purpose

Several studies demonstrate an increased prevalence and concordance of inflammatory bowel disease among the relatives of patients. Other studies suggest that genetic influence is over-estimated. The aims of this study are to evaluate the phenotypic expression and the treatment requirements in familial inflammatory bowel disease, to study the relationship between number of relatives and degree of kinship with disease severity and to quantify the impact of family aggregation compared to other environmental factors.

Methods

Observational analytical study of 1211 patients followed in our unit. We analyzed, according to the existence of familial association, number and degree of consanguinity, the phenotypic expression, complications, extraintestinal manifestations, treatment requirements, and mortality. A multivariable analysis considering smoking habits and non-steroidal-anti-inflammatory drugs was performed.

Results

14.2% of patients had relatives affected. Median age at diagnosis tended to be lower in the familial group, 32 vs 29, p = 0.07. In familial ulcerative colitis, there was a higher proportion of extraintestinal manifestations: peripheral arthropathy (OR = 2.3, p = 0.015) and erythema nodosum (OR = 7.6, p = 0.001). In familial Crohn’s disease, there were higher treatment requirements: immunomodulators (OR = 1.8, p = 0.029); biologics (OR = 1.9, p = 0.011); and surgery (OR = 1.7, p = 0.044). The abdominal abscess increased with the number of relatives affected: 5.1% (sporadic), 7.0% (one), and 14.3% (two or more), p=0.039. These associations were maintained in the multivariate analysis.

Conclusions

Familial aggregation is considered a risk factor for more aggressive disease and higher treatment requirements, a tendency for earlier onset, more abdominal abscess, and extraintestinal manifestations, remaining a risk factor analyzing the influence of some environmental factors.

     

Deletion of LCE3C and LCE3B is a susceptibility factor for psoriatic arthritis: A study in Spanish and Italian populations and meta‐analysis

Objective

The LCE3C_LCE3B‐del variant is associated with psoriasis and rheumatoid arthritis. Its role in psoriatic arthritis (PsA) is unclear, however, as shown by 3 recent studies with contradictory results. In order to investigate whether LCE3C_LCE3B‐del constitutes a risk factor for PsA susceptibility, we first tested this variant in patients with PsA from Spanish and Italian populations and then performed a meta‐analysis including the previous case–control studies.

Methods

We genotyped LCE3C_LCE3B‐del and its tag single‐nucleotide polymorphism (SNP), rs4112788, in an original discovery cohort of 424 Italian patients with PsA and 450 unaffected control subjects. A Spanish replication cohort consisting of 225 patients with PsA and 469 control subjects was also genotyped. A meta‐analysis considering 7,758 control subjects and 2,325 patients with PsA was also performed.

Results

We observed a significant association between PsA and the LCE3C_LCE3B‐del tag SNP in the Italian and Spanish cohorts, with an overall corrected P value of 0.00019 and a corresponding odds ratio of 1.35 (95% confidence interval 1.14–1.59). Stratified analyses by subphenotype indicated a stronger association for patients with oligoarticular disease. Meta‐analysis including data from all previous published studies confirmed an association of PsA with the LCE3C_LCE3B‐del tag SNP.

Conclusion

LCE3C_LCE3B‐del is a susceptibility factor for PsA, confirming the existence of a shared risk factor involving the epidermal skin barrier in autoimmune disorders.

     

Ontogeny of adenohypophyseal cells in the pituitary of the American shad (Alosa sapidissima)

The distribution and ontogeny of adenohypophyseal cells have been studied in the pituitary gland of embryos, larvae, and juveniles of the clupeid American shad (Alosa sapidissima) using immunocytochemical techniques. In juvenile specimens, adenohypophysis was composed of rostral pars distalis (RPD), formed by cavities lined by prolactin (PRL), adrenocorticotropic hormone (ACTH), and gonadotropic hormone (GTH) cells; proximal pars distalis (PPD), containing growth hormone (GH), GTH, and putative thyroid stimulating hormone (TSH) cells; and pars intermedia (PI) with somatolactin (SL) and melanophore stimulating hormone (MSH) cells. At 3 days post-fertilization (3 days pre-hatching) the pituitary of embryos consisted of an oval mass of cells, close to the ventral margin of the diencephalon, divided in rostral and caudal regions. At this time PRL and ACTH cells appeared in the rostral region of the adenohypophysis, while SL cells were observed in the caudal region where MSH cells showed reactivity 1 day before hatching. At variance, GH cells showed a weak immunoreactivity in the rostral portion at hatching that increased 2 days latter. GTH cells also showed weak immunoreactivity in the rostral region of the adenohypophysis at hatching time. Two days later GTH cells were located in the rostral and central regions of the adenohypophysis. At hatching, the neurohypophysis was very small and no nerve processes were seen to penetrate the adenohypophysis tissue. After hatching, the pituitary gland elongated and in 7 days old larvae, the RPD showed a small lumen surrounded by a palisade of PRL, ACTH, and GHT cells; the PPD showed GH and GTH cells while the PI contained SL and MSH cells. The adenohypophysis and neural lobe increased in size with development and, in 42 days old larvae, they were similar to those of juvenile specimens.     

Induction of tumor NK-cell immunity by anti-CD69 antibody therapy

The leukocyte activation marker CD69 is a novel regulator of the immune response, modulating the production of cytokines including transforming growth factor-beta (TGF-beta). We have generated an antimurine CD69 monoclonal antibody (mAb), CD69.2.2, which down-regulates CD69 expression in vivo but does not deplete CD69-expressing cells. Therapeutic administration of CD69.2.2 to wild-type mice induces significant natural killer (NK) cell-dependent antitumor responses to major histocompatibility complex (MHC) class I low RMA-S lymphomas and to RM-1 prostatic carcinoma lung metastases. These in vivo antitumor responses are comparable to those seen in CD69(-/-) mice. Enhanced host NK cytotoxic activity correlates with a reduction in NK-cell TGF-beta production and is independent of tumor priming. In vitro studies demonstrate the novel ability of anti-CD69 mAbs to activate resting NK cells in an Fc receptor-independent manner, resulting in a substantial increase in both NK-cell cytolytic activity and interferon gamma (IFNgamma) production. Modulation of the innate immune system with monoclonal antibodies to host CD69 thus provides a novel means to antagonize tumor growth and metastasis.     

Central human B cell tolerance manifests with a distinctive cell phenotype and is enforced via CXCR4 signaling in hu-mice

Central B cell tolerance, the process restricting the development of many newly generated autoreactive B cells, has been intensely investigated in mouse cells while studies in humans have been hampered by the inability to phenotypically distinguish autoreactive and nonautoreactive immature B cell clones and the difficulty in accessing fresh human bone marrow samples. Using a human immune system mouse model in which all human Igκ⁺ B cells undergo central tolerance, we discovered that human autoreactive immature B cells exhibit a distinctive phenotype that includes lower activation of ERK and differential expression of CD69, CD81, CXCR4, and other glycoproteins. Human B cells exhibiting these characteristics were observed in fresh human bone marrow tissue biopsy specimens, although differences in marker expression were smaller than in the humanized mouse model. Furthermore, the expression of these markers was slightly altered in autoreactive B cells of humanized mice engrafted with some human immune systems genetically predisposed to autoimmunity. Finally, by treating mice and human immune system mice with a pharmacologic antagonist, we show that signaling by CXCR4 is necessary to prevent both human and mouse autoreactive B cell clones from egressing the bone marrow, indicating that CXCR4 functionally contributes to central B cell tolerance.

The bone marrow tissue is the major site of postnatal B cell development in both mice and humans (1, 2). B lymphopoiesis begins when hematopoietic stem cells (HSCs) differentiate into common lymphoid progenitors that commit to the B cell lineage by developing into precursors of B cell progenitors (3). These precursors undergo a step-by-step differentiation process that is accompanied by the rearrangement of V, D, and J gene segments at the immunoglobulin (Ig) heavy chain locus first and then, after a heavy (H) chain is expressed, of V and J segments at the Ig light chain loci, Igκ and Igλ (4). The de novo synthesized H and L Ig chains pair with the signaling molecules CD79A and CD79B to form a B cell receptor (BCR) that is expressed on the cell surface as IgM and that functions as antigen receptor (5). These newly generated IgM⁺ B cells, which are identified as immature B cells, undergo further differentiation into transitional B cells that enter the circulation and complete their maturation in the spleen (6).A feature of B cell development is that the assembly of the Ig H and L chain genes occurs through random reassortment of numerous V(D)J gene segments, which facilitates the generation of a vast number of antibody specificities, one per each developing B cell (4). While this feature is crucial to the development and maintenance of a B cell population and antibody repertoire capable of recognizing any pathogen, the disadvantage is that the majority of these V(D)J gene sequences encode antibodies that are self-reactive (7, 8). It is well established that the entry of newly generated autoreactive B cell clones into the peripheral tissue is restricted by the physiological process of tolerance, a process that evolved to reduce the chance of autoantibody responses and autoimmunity. Indeed, antibody repertoire studies in mice and humans as well as studies with Ig transgenic and knock-in mice have amply demonstrated that the transition from the bone marrow immature B cell stage to the peripheral B cell stage is accompanied by a significant decrease (about twofold) in the frequency of autoreactive clones (8, 9), and this is because clones with BCRs that exhibit high avidity for self-antigens are prevented from entering the peripheral B cell population (10–12).The process of central B cell tolerance has been mainly characterized in mouse models where it operates via the maintenance of RAG1/2-mediated VJ recombination at the light chain loci (i.e., receptor editing) and by inducing cell death (i.e., clonal deletion) in clones in which receptor editing fails to provide a nonautoreactive specificity within a few days (13–16). A major bottleneck in studying central B cell tolerance in humans is the difficulty of acquiring fresh bone marrow samples and the inability to identify and distinguish autoreactive from nonautoreactive B cell clones. Single-cell cloning of Ig genes from newly formed bone marrow B cells that emigrated into the blood, together with the expression and testing of the antibodies they encode, have provided estimates of the efficiency of central B cell tolerance in humans (7, 17). These studies have elegantly shown that central B cell tolerance is significantly less efficient in many autoimmune patients, and particularly in those with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), type-1 diabetes (T1D), and Sjögren’s syndrome (18–22). These studies have further shown that the genetic variant R620W of the PTPN22 protein tyrosine phosphatase, a variant linked to a higher risk for the development of autoimmunity, is also associated with higher frequencies of autoreactive/polyreactive clones among the new emigrant transitional B cells, revealing a defective central tolerance checkpoint in individuals carrying this risk allele (23).To elucidate mechanisms of development and tolerance of human B cells, our group has investigated human immune system humanized mice (HIS hu-mice) in which human B lymphocytes develop subsequent to the engraftment of human umbilical cord blood HSCs (24, 25). With this intent, we have previously created a HIS hu-mouse model in which all mouse cells express a synthetic membrane-bound self-antigen (Hcκ) that reacts at high avidity with developing human Igκ⁺ B cells (26). In this model, all human κ⁺ B cells are autoreactive and undergo central tolerance in the bone marrow via a mix of receptor editing and clonal deletion (26).In the present study we aimed to exploit this HIS hu-mouse model to discover markers that distinguish human autoreactive immature B cells from nonautoreactive cells, as well as to identify pathways that contribute mechanistically to the enforcement of central B cell tolerance. Our data show that human autoreactive immature B cells contrast from nonautoreactive cells by up-regulating CD69 and CXCR4 while downmodulating the expression of IgM, CD19, CD81, and BAFFR as well as maintaining lower ERK activation. Cells with a similar phenotype, although more subtle, were also observed within the developing immature B cell population of human bone marrow specimens. Moreover, small differences in the expression of these markers and in the amount of sera autoantibodies were found in HIS hu-mice generated with HSCs from some donors genetically predisposed to autoimmunity. Finally, our data demonstrate that retention of human autoreactive B cells in the bone marrow does not rely on CD69 expression while is critically dependent on CXCR4 signaling, indicating that the CXCR4–CXCL12 pathway enforces central B cell tolerance.     

The functional immaturity of dendritic cells can be relevant to increased tolerance associated with cord blood transplantation

BACKGROUND: Cord blood (CB) transplants have a significantly lower incidence of graft-versus-host disease (GVHD) compared to marrow or peripheral blood transplants. Because antigen-presenting cells and regulatory T cells (Treg) are involved in transplant tolerance, this study was aimed at analyzing the distribution of dendritic cells (DCs) and CD14+ monocyte-specific subsets in CB and adult peripheral blood (APB) and comparing the ability of DCs from these two blood sources to induce CD4+ Treg. STUDY DESIGN AND METHODS: Myeloid DCs (mDCs), plasmacytoid DCs, the CD14+ cell subsets CD14+CD16+ and CD14+CD209+, and CD4+ T cells were analyzed by fluorescence-activated cell sorting (FACS) in whole blood. To evaluate the functionality of DCs, isolated CD3+ T cells from an adult donor were cultured with allogenic DC-enriched fraction from CB or APB, and CD4+ Treg generation was determined by FACS. Additionally, tumor necrosis factor (TNF)-alpha and interferon (IFN)-alpha release by DCs was measured. RESULTS: CB had a lesser frequency of DCs and specific CD14+ monocyte subsets than APB. After stimulation, monocytes from CB secreted less TNF-alpha than those from APB. Moreover, DCs from CB exhibited a more immature phenotype and had a decreased capacity to release TNF-alpha and IFN-alpha than those derived from APB, but on the contrary, they were efficient inducers of CD4+ T cells with a phenotype of Treg. CONCLUSION: The tolerogenic immunophenotype and diminished functionality of CB DCs can be important to create a microenvironment where Treg develop, that in turn may be relevant to observed lower incidence of chronic GVHD after CB transplantation.     

In vivo protective effect of melatonin on cadmium-induced changes in redox balance and gene expression in rat hypothalamus and anterior pituitary

Cadmium (Cd) is widely used in industrial applications and is an important side contaminant of agricultural products. As an endocrine disruptor, Cd modifies pituitary hormone release. It has been shown that this metal causes oxidative stress in primary cultures of anterior pituitary cells. To examine whether Cd induces redox damage in the hypothalamic-pituitary axis in vivo and to evaluate the efficacy of the antioxidant molecule melatonin to prevent Cd activity, rats were exposed to Cd (5 p.p.m. in drinking water) with or without melatonin (3 microg/mL drinking water) for 1 month. In the anterior pituitary, Cd increased lipid peroxidation and mRNA levels for heme oxygenase-1 (HO-1) at both time intervals tested (09:00 and 01:00 hr, beginning of rest span and middle of activity span, respectively). Melatonin administration prevented the Cd-induced increase in both parameters. In the hypothalamus, Cd affected the levels of mRNA for HO-1 by decreasing it in the evening. Melatonin reduced hypothalamic HO-1 gene expression. Cd treatment augmented gene expression of nitric oxide synthase (NOS)1 and NOS2 in the pituitary whereas melatonin decreased it, impairing the activity of Cd. Exposure to Cd increased the levels of hypothalamic NOS1 mRNA at 09:00 hr and decreased the levels of NOS2 mRNA at 01:00 hr, with melatonin treatment preventing Cd effects. Cd treatment decreased plasma thyroid-stimulating hormone levels at both examined times, while melatonin reversed the effect of Cd at 09:00 hr and partially counteracted the effect at 01:00 hr. There were important variations between day and night in the expression of all the genes tested in both tissues. Melatonin treatment was effective reducing all examined effects of Cd, documenting its effectiveness to protect the rat hypothalamic-pituitary axis from the toxic metal effects.