Metabolic Adaptation Establishes Disease Tolerance to Sepsis.

Sepsis is an often lethal syndrome resulting from maladaptive immune and metabolic responses to infection, compromising host homeostasis. Disease tolerance is a defense strategy against infection that preserves host homeostasis without exerting a direct negative impact on pathogens. Here, we demonstrate that induction of the iron-sequestering ferritin H chain (FTH) in response to polymicrobial infections is critical to establish disease tolerance to sepsis. The protective effect of FTH is exerted via a mechanism that counters iron-driven oxidative inhibition of the liver glucose-6-phosphatase (G6Pase), and in doing so, sustains endogenous glucose production via liver gluconeogenesis. This is required to prevent the development of hypoglycemia that otherwise compromises disease tolerance to sepsis. FTH overexpression or ferritin administration establish disease tolerance therapeutically. In conclusion, disease tolerance to sepsis relies on a crosstalk between adaptive responses controlling iron and glucose metabolism, required to maintain blood glucose within a physiologic range compatible with host survival.

Correlations between the NMR Lipoprotein Profile, APOE Genotype, and Cholesterol Efflux Capacity of Fasting Plasma from Cognitively Healthy Elderly Adults.

Cholesterol efflux capacity (CEC) is of interest given its potential relationship with several important clinical conditions including Alzheimer's disease. The inactivation of the APOE locus in mouse models supports the idea that it is involved in determining the CEC. With that in mind, we examine the impact of the plasma metabolome profile and the APOE genotype on the CEC in cognitively healthy elderly subjects. The study subjects were 144 unrelated healthy individuals. The plasma CEC was determined by exposing cultured mouse macrophages treated with BODIPY-cholesterol to human plasma. The metabolome profile was determined using NMR techniques. Multiple regression was performed to identify the most important predictors of CEC, as well as the NMR features most strongly associated with the APOE genotype. Plasma 3-hydroxybutyrate was the variable most strongly correlated with the CEC (r = 0.365; p = 7.3 × 10-6). Male sex was associated with a stronger CEC (r = -0.326, p = 6.8 × 10-5). Most of the NMR particles associated with the CEC did not correlate with the APOE genotype. The NMR metabolomics results confirmed the APOE genotype to have a huge effect on the concentration of plasma lipoprotein particles as well as those of other molecules including omega-3 fatty acids. In conclusion, the CEC of human plasma was associated with ketone body concentration, sex, and (to a lesser extent) the other features of the plasma lipoprotein profile. The APOE genotype exerted only a weak effect on the CEC via the modulation of the lipoprotein profile. The APOE locus was associated with omega-3 fatty acid levels independent of the plasma cholesterol level.

Renal control of disease tolerance to malaria.

Malaria, the disease caused by Plasmodium spp. infection, remains a major global cause of morbidity and mortality. Host protection from malaria relies on immune-driven resistance mechanisms that kill Plasmodium However, these mechanisms are not sufficient per se to avoid the development of severe forms of disease. This is accomplished instead via the establishment of disease tolerance to malaria, a defense strategy that does not target Plasmodium directly. Here we demonstrate that the establishment of disease tolerance to malaria relies on a tissue damage-control mechanism that operates specifically in renal proximal tubule epithelial cells (RPTEC). This protective response relies on the induction of heme oxygenase-1 (HMOX1; HO-1) and ferritin H chain (FTH) via a mechanism that involves the transcription-factor nuclear-factor E2-related factor-2 (NRF2). As it accumulates in plasma and urine during the blood stage of Plasmodium infection, labile heme is detoxified in RPTEC by HO-1 and FTH, preventing the development of acute kidney injury, a clinical hallmark of severe malaria.

Production of anti-LPS IgM by B1a B cells depends on IL-1ß and is protective against lung infection with Francisella tularensis LVS.

The role of IL-1ß and IL-18 during lung infection with the gram-negative bacterium Francisella tularensis LVS has not been characterized in detail. Here, using a mouse model of pneumonic tularemia, we show that both cytokines are protective, but through different mechanisms. Il-18-/- mice quickly succumb to the infection and showed higher bacterial burden in organs and lower level of IFNγ in BALF and serum compared to wild type C57BL/6J mice. Administration of IFNγ rescued the survival of Il-18-/- mice, suggesting that their decreased resistance to tularemia is due to inability to produce IFNγ. In contrast, mice lacking IL-1 receptor or IL-1ß, but not IL-1α, appeared to control the infection in its early stages, but eventually succumbed. IFNγ administration had no effect on Il-1r1-/- mice survival. Rather, Il-1r1-/- mice were found to have significantly reduced titer of Ft LPS-specific IgM. The anti-Ft LPS IgM was generated in a IL-1ß-, TLR2-, and ASC-dependent fashion, promoted bacteria agglutination and phagocytosis, and was protective in passive immunization experiments. B1a B cells produced the anti-Ft LPS IgM and these cells were significantly decreased in the spleen and peritoneal cavity of infected Il-1b-/- mice, compared to C57BL/6J mice. Collectively, our results show that IL-1ß and IL-18 activate non-redundant protective responses against tularemia and identify an essential role for IL-1ß in the rapid generation of pathogen-specific IgM by B1a B cells.

Neutrophil elastase causes tissue damage that decreases host tolerance to lung infection with burkholderia species.

Two distinct defense strategies can protect the host from infection: resistance is the ability to destroy the infectious agent, and tolerance is the ability to withstand infection by minimizing the negative impact it has on the host's health without directly affecting pathogen burden. Burkholderia pseudomallei is a Gram-negative bacterium that infects macrophages and causes melioidosis. We have recently shown that inflammasome-triggered pyroptosis and IL-18 are equally important for resistance to B. pseudomallei, whereas IL-1ß is deleterious. Here we show that the detrimental role of IL-1ß during infection with B. pseudomallei (and closely related B. thailandensis) is due to excessive recruitment of neutrophils to the lung and consequent tissue damage. Mice deficient in the potentially damaging enzyme neutrophil elastase were less susceptible than the wild type C57BL/6J mice to infection, although the bacterial burdens in organs and the extent of inflammation were comparable between C57BL/6J and elastase-deficient mice. In contrast, lung tissue damage and vascular leakage were drastically reduced in elastase-deficient mice compared to controls. Bradykinin levels were higher in C57BL/6 than in elastase-deficient mice; administration of a bradykinin antagonist protected mice from infection, suggesting that increased vascular permeability mediated by bradykinin is one of the mechanisms through which elastase decreases host tolerance to melioidosis. Collectively, these results demonstrate that absence of neutrophil elastase increases host tolerance, rather than resistance, to infection by minimizing host tissue damage.

Inflammasome-dependent pyroptosis and IL-18 protect against Burkholderia pseudomallei lung infection while IL-1ß is deleterious.

Burkholderia pseudomallei is a Gram-negative bacterium that infects macrophages and other cell types and causes melioidosis. The interaction of B. pseudomallei with the inflammasome and the role of pyroptosis, IL-1ß, and IL-18 during melioidosis have not been investigated in detail. Here we show that the Nod-like receptors (NLR) NLRP3 and NLRC4 differentially regulate pyroptosis and production of IL-1ß and IL-18 and are critical for inflammasome-mediated resistance to melioidosis. In vitro production of IL-1ß by macrophages or dendritic cells infected with B. pseudomallei was dependent on NLRC4 and NLRP3 while pyroptosis required only NLRC4. Mice deficient in the inflammasome components ASC, caspase-1, NLRC4, and NLRP3, were dramatically more susceptible to lung infection with B. pseudomallei than WT mice. The heightened susceptibility of Nlrp3⁻/⁻ mice was due to decreased production of IL-18 and IL-1ß. In contrast, Nlrc4⁻/⁻ mice produced IL-1ß and IL-18 in higher amount than WT mice and their high susceptibility was due to decreased pyroptosis and consequently higher bacterial burdens. Analyses of IL-18-deficient mice revealed that IL-18 is essential for survival primarily because of its ability to induce IFNγ production. In contrast, studies using IL-1RI-deficient mice or WT mice treated with either IL-1ß or IL-1 receptor agonist revealed that IL-1ß has deleterious effects during melioidosis. The detrimental role of IL-1ß appeared to be due, in part, to excessive recruitment of neutrophils to the lung. Because neutrophils do not express NLRC4 and therefore fail to undergo pyroptosis, they may be permissive to B. pseudomallei intracellular growth. Administration of neutrophil-recruitment inhibitors IL-1ra or the CXCR2 neutrophil chemokine receptor antagonist antileukinate protected Nlrc4⁻/⁻ mice from lethal doses of B. pseudomallei and decreased systemic dissemination of bacteria. Thus, the NLRP3 and NLRC4 inflammasomes have non-redundant protective roles in melioidosis: NLRC4 regulates pyroptosis while NLRP3 regulates production of protective IL-18 and deleterious IL-1ß.

Participation of calbindin-D28K in nociception: results from calbindin-D28K knockout mice.

Since calbindin-D(28K) (CB-D(28K))-positive neurons have been related to nociceptive sensory processing, we have hypothesized that altered CB-D(28K) expression could alter nociceptive transmission. We have used +/+ and -/- knockout (KO) mice for CB-D(28k) in different behavioral models of pain and sensory responses at the caudalis subdivision of the trigeminal spinal nucleus in order to understand how this protein may participate in nociception. Behavioral responses to formalin injection in the hind paw or at the whisker pad or in the hind paw glutamate or i.p. acetic acid tests showed an increase of the pain threshold in CB-D(28k) -/- mice. KO mice showed a diminution of the inhibitory activity at Sp5C nucleus and a marked reduction of GABA content. Sp5C neurons from CB-D(28k) -/- mice did not change their spontaneous activity or tactile response after formalin injection in the whisker pad. In contrast, Sp5C neurons increased their spontaneous firing rate and tactile response after formalin injection in their receptive field in CB-D(28k) +/+ mice. The results of this study demonstrate the active role played by CB-D(28k) in nociceptive sensory transmission. The lack of this calcium binding protein, associated to deficient GABAergic neurotransmission, translates into dysfunction of sensory processing of nociceptive stimuli.

Micro-Topographies Induce Epigenetic Reprogramming and Quiescence in Human Mesenchymal Stem Cells.

Biomaterials can control cell and nuclear morphology. Since the shape of the nucleus influences chromatin architecture, gene expression and cell identity, surface topography can control cell phenotype. This study provides fundamental insights into how surface topography influences nuclear morphology, histone modifications, and expression of histone-associated proteins through advanced histone mass spectrometry and microarray analysis. The authors find that nuclear confinement is associated with a loss of histone acetylation and nucleoli abundance, while pathway analysis reveals a substantial reduction in gene expression associated with chromosome organization. In light of previous observations where the authors found a decrease in proliferation and metabolism induced by micro-topographies, they connect these findings with a quiescent phenotype in mesenchymal stem cells, as further shown by a reduction of ribosomal proteins and the maintenance of multipotency on micro-topographies after long-term culture conditions. Also, this influence of micro-topographies on nuclear morphology and proliferation is reversible, as shown by a return of proliferation when re-cultured on a flat surface. The findings provide novel insights into how biophysical signaling influences the epigenetic landscape and subsequent cellular phenotype.

Neuroprotective effect of guanosine against glutamate-induced cell death in rat hippocampal slices is mediated by the phosphatidylinositol-3 kinase/Akt/ glycogen synthase kinase 3ß pathway activation and inducible nitric oxide synthase inhibition.

Excitotoxicity and cell death induced by glutamate are involved in many neurodegenerative disorders. We have previously demonstrated that excitotoxicity induced by millimolar concentrations of glutamate in hippocampal slices involves apoptotic features and glutamate-induced glutamate release. Guanosine, an endogenous guanine nucleoside, prevents excitotoxicity by its ability to modulate glutamate transport. In this study, we have evaluated the neuroprotective effect of guanosine against glutamate-induced toxicity in hippocampal slices and the mechanism involved in such an effect. We have found that guanosine (100 µM) was neuroprotective against 1 mM glutamate-induced cell death through the inhibition of glutamate release induced by glutamate. Guanosine also induced the phosphorylation and, thus, activation of protein kinase B (PKB/Akt), a downstream target of phosphatidylinositol-3 kinase (PI3K), as well as phosphorylation of glycogen synthase kinase 3ß, which has been reported to be inactivated by Akt after phosphorylation at Ser9. Glutamate treated hippocampal slices showed increased inducible nitric oxide synthase (iNOS) expression that was prevented by guanosine. Slices preincubated with SNAP (an NO donor), inhibited the protective effect of guanosine. LY294002 (30 µM), a PI3K inhibitor, attenuated guanosine-induced neuroprotection, guanosine prevention of glutamate release, and guanosine-induced GSK3ß(Ser9) phosphorylation but not guanosine reduction of glutamate-induced iNOS expression. Taken together, the results of this study show that guanosine protects hippocampal slices by a mechanism that involves the PI3K/Akt/GSK3ß(Ser9) pathway and prevention of glutamate-induced glutamate release. Furthermore, guanosine also reduces glutamate-induced iNOS by a PI3K/Akt-independent mechanism.

Cholinergic and neuroprotective drugs for the treatment of Alzheimer and neuronal vascular diseases. II. Synthesis, biological assessment, and molecular modelling of new tacrine analogues from highly substituted 2-aminopyridine-3-carbonitriles.

The synthesis, biological assessment, and molecular modelling of new tacrine analogues 11-22 is described. Compounds 11-22 have been obtained by Friedländer-type reaction of 2-aminopyridine-3-carbonitriles 1-10 with cyclohexanone or 1-benzyl-4-piperidone. The biological evaluation showed that some of these molecules were good AChE inhibitors, in the nanomolar range, and quite selective regarding the inhibition of BuChE, the most potent being 5-amino-2-(dimethylamino)-6,7,8,9-tetrahydrobenzo[1,8-b]-naphthyridine-3-carbonitrile (11) [IC(50) (EeAChE: 14nM); IC(50) (eqBuChE: 5.2µM]. Kinetic studies on the easily available and potent anticholinesterasic compound 5-amino-2-(methoxy)-6,7,8,9-tetrahydrobenzo[1,8-b]-naphthyridine-3-carbonitrile (16) [IC(50) (EeAChE: 64nM); IC(50) (eqBuChE: 9.6µM] showed that this compound is a mixed-type inhibitor (K(i)=69.2nM) of EeAChE. Molecular modelling on inhibitor 16 confirms that this compound, as expected and similarly to tacrine, binds at the catalytic active site of EeAChE. The neuroprotective profile of molecules 11-22 has been investigated in SH-SY5Y neuroblastoma cells stressed with a mixture of oligomycin-A/rotenone. Compound 16 was also able to rescue by 50% cell death induced by okadaic acid in SH-SY5Y cells. From these results we conclude that the neuroprotective profile of these molecules is moderate, the most potent being compounds 12 and 17 which reduced cell death by 29%. Compound 16 does not affect ACh- nor K(+)-induced calcium signals in bovine chromaffin cells. Consequently, tacrine analogues 11-22 can be considered attractive therapeutic molecules on two key pharmacological targets playing key roles in the progression of Alzheimer, that is, cholinergic dysfunction and oxidative stress, as well as in neuronal cerebrovascular diseases.

Role of the inflammasome, IL-1ß, and IL-18 in bacterial infections.

The inflammasome is an important innate immune pathway that regulates at least two host responses protective against infections: (1) secretion of the proinflammatory cytokines IL-1ß and IL-18 and (2) induction of pyroptosis, a form of cell death. Inflammasomes, of which different types have been identified, are multiprotein complexes containing pattern recognition receptors belonging to the Nod-like receptor family or the PYHIN family and the protease caspase-1. The molecular aspects involved in the activation of different inflammasomes by various pathogens are being rapidly elucidated, and their role during infections is being characterized. Production of IL-1ß and IL-18 and induction of pyroptosis of the infected cell have been shown to be protective against many infectious agents. Here, we review the recent literature concerning inflammasome activation in the context of bacterial infections and identify important questions to be answered in the future.

Bilateral Drug-Induced Uveitis and Epiretinal Membrane during the Treatment of a Metastatic Cutaneous Melanoma.

Purpose: To report the case of a drug-induced uveitis during the treatment of a metastatic cutaneous melanoma.Case report: A 75-year-old female treated with Dabrafenib and Trametinib due to a cutaneous melanoma stage IV presented with blurriness in both eyes. The examination revealed bilateral intraocular signs of inflammation, and fundoscopy showed bilateral changes at the posterior pole, such as chorioretinal folds and Neurosensory Retinal Detachment (NRD). Due to a worsening of Visual Acuity (VA) and persistence of intraocular inflammation in spite of topical prednisolone acetate treatment, the therapy with Dabrafenib + Trametinib was interrupted, after having been administered for 4 months, and replaced by Nivolumab. Fundus abnormalities and intraocular inflammation improved, but VA remained low due to the presence of an epiretinal membrane in the right eye. Then, a decreasing course of prednisolone eye drops was introduced for one more month and finally interrupted without the cessation of Nivolumab.Conclusion: Drug-induced uveitis has been increasing in the last few years due to the development of new biological agents for treatment of different types of tumours. The management of these adverse events should be handled in collaboration with oncologists and ophthalmologists and must be individualised and based on the risk-benefit balance. A case report of an uveitis and subsequent development of an epiretinal membrane during the treatment with Dabrafenib, Trametinib and subsequent Nivolumab for a metastatic cutaneous melanoma is reported here, in order to note the importance of an adequate follow-up of patients treated with these drugs.

Haemophilus Influenzae Endogenous Endophthalmitis in an Immunocompetent Host.

Purpose: To report a case of endogenous endophthalmitis caused by Haemophilus influenzae in an immunocompetent host.Case report: A 13-year-old male presented with pain, blurriness, and decreased Visual Acuity (VA) of Hand Motion in his right eye. Slit-lamp examination revealed hypopyon. Fundoscopy showed vitritis, vasculitis, and retinal infiltrates. Echography revealed vitreous condensations. Empirical treatment with intravitreal Ganciclovir, oral Valacyclovir, and Dexamethasone was initiated with no improvement. Vitreous culture revealed Haemophilus influenzae growth. Then, intravenous Ciprofloxacin and Cefotaxime and intravitreal Ceftazidime were administered with gradual improvement. Lensectomy with Pars Plana Vitrectomy and intraocular tamponade was performed. Nevertheless, the visual outcome was poor.Conclusion: Pediatric endogenous bacterial endophthalmitis is a rare but potentially devastating infection which is often misdiagnosed. Moreover, we want to highlight the importance of an adequate clinical suspicion in cases of H. influenzae to prevent the serious complications seen in this report.

Prognostic Factor Utility of BAP1 Immunohistochemistry in Uveal Melanoma: A Single Center Study in Spain.

Even today, the mortality rate for uveal melanoma (UM) remains very high. In our research, we sought to determine which pathological and clinical features were correlated with the prognosis of UM. BAP1 (BRCA1-Associated Protein 1) gene mutation has been analyzed as one of the strongest predictors for metastasis in UM. The BAP1 gene codifies the BAP1 protein which has a tumor suppressor function. The presence of this protein can be determined by BAP1 immunohistochemical staining. Eighty-four uveal melanoma patients and forty enucleated eyeballs were examined. Metastasis was present in 24 patients. Nuclear BAP1 staining was low in 23 patients. The presence of a higher large basal diameter tumor (p < 0.001), tumor infiltrating lymphocytes (p = 0.020), and a lack of nuclear BAP1 immunostaining (p = 0.001) ocurred significantly more often in the metastatic group. Metastasis-free survival was lower in patients with low nuclear BAP1 staining (p = 0.003). In conclusion, to the best of our knowledge, this is the first time that BAP1 staining has been studied in uveal melanoma in a Spanish community. We believe that this technique should become routine in the pathological examination of uveal melanoma in order to allow adequate classification of patients and to establish an individual follow-up plan.

Epithelial conjunctival neoplasias - the importance of an early diagnosis and optimal treatment.

Objective: To emphasize the importance of an early diagnosis and an adequate treatment in conjunctival tumors. Methods: We present two clinical cases and compare the course of each case: one of conjunctival intraepithelial neoplasia (CIN) which took a positive course, and a fatal case of squamous cell carcinoma (SCC) with intraocular and orbital extension. Results: Epithelial conjunctival malignancies are one of the most prevalent ocular surface tumors. Among these, CIN are the most common. CIN have an excellent prognosis, given adequate treatment. However, when the diagnosis of CIN is late, the epithelial basement membrane will be affected, resulting in SCC. SCC may have poorer results due to its capacity to infiltrate near tissues and create distant metastasis. Conclusion: It is not common today to treat patients with orbital extension of SCC; however, it is crucial to note the importance of an early diagnosis of conjunctival malignancies. An early diagnosis is essential to prevent the transformation to other life-threatening types.

Itching eyes after itching around the head.

Objective: To report the occurrence and management of an eyelashes infestation by Phthirus pubis. Methods: A 27-year-old female presented with itching in her right eye and head after she had been traveling in southern Italy five days earlier. Visual acuity (VA) was 20/20 in both eyes. Slit-lamp examination showed bilateral blepharitis. Moreover, mobile insects and eggs attached to the eyelashes were observed. A microbiological study was performed with a Phthirus pubis result. The patient was treated with mechanical dislodging. Results: The resolution of the infection was carried out removing every insect and egg. A vaseline application twice daily for 7 days was necessary to stifle any nits that could remain. Conclusions: The eyelashes pediculosis is frequently caused by Phthirus pubis. Only a minor percentage of the cases are due to Phthirus capitis, but the differential diagnosis is essential: there are Phthirus pubis pediculosis cases due to sexual abuse. A sexual history and screening for other sexually transmitted diseases is warranted.

[Handheld laser maculopathy: two case reports]. / Retinopatía por puntero láser: presentación de dos casos.

The improper use of laser pointers, especially for recreational use in children, may cause sight-threatening retinal injuries. The retinal damage it is not well characterized because most publications are isolated cases or small series. The treatment and visual prognosis are variable according to the morphology of the macular damage. In some cases, there is no treatment, and spontaneous healing can be developed; however, others require surgery. In a series of 13 cases, 1 required surgery and the rest observation; 3 patients obtained a spontaneous healing with visual acuity of 10/10. We describe two patients aged 16 and 12 years with decreased visual acuity. Macular alterations appear in the fundus of the eye. The visual acuity of both recovered completely without treatment.

El uso indebido de los punteros láser, especialmente el recreativo en los niños, puede causar lesiones retinianas que amenazan la visión. El daño retiniano que producen no está bien caracterizado, debido a que la mayoría de las publicaciones son casos aislados o series pequeñas. El tratamiento y el pronóstico visual es variable según la morfología del daño macular que presenten. En algunos casos, no existe tratamiento, y pueden evolucionar a la curación espontánea; sin embargo, otros precisan cirugía. En una serie de 13 casos, uno requirió cirugía, mientras que el resto necesitó solo observación. De estos 13 casos, 3 pacientes se curaron en forma espontánea, con agudeza visual de 10/10. Se describen dos pacientes de 16 y 12 años con disminución de agudeza visual tras el uso indebido de punteros láser. En el fondo de ojo, presentaron alteraciones maculares. La agudeza visual de ambos se recuperó completamente sin tratamiento.

Novel Multitarget Hybrid Compounds for the Treatment of Alzheimer's Disease.

Alzheimer's disease (AD) is the most prevalent among the aging diseases known as neurodegenerative disorders. Drug design programs over the last two decades were mainly based on the cholinergic, the amyloid or the tau hypothesis. However, none of the new drugs have a real impact on the outcome of the disease. The complex nature of AD has led to new approaches for drug development programs, the multitarget drug design hypothesis. Based on this hypothesis, the generation of multitarget hybrid compounds from previously known active molecules has been one of the most widely used to obtain new candidates for the future treatment of AD. Here, we summarize recent developments based on the hybridization hypothesis to obtain a potential clinical candidate for AD.

Drusas papilares asociadas a pérdida de campo visual / Optic disc drusen associated to visual field loss

Paciente de 14 años remitida para valorar fondo de ojo por cefalea. Presenta agudeza visual de 8/10 en ambos ojos y en fundoscopia se visualizan papilas de contornos escasamente definidos. Se solicita Autofluorescencia identificando lesiones autofluorescentes compatibles con drusas (Figura 1A,B). La OCT de fibras revela afectación sectorial bilateral sin papiledema (Figura 1C,D) y el campo visual mostró una afectación del hemicampo nasal bilateral (Figura 1E,F). Las drusas en el nervio óptico representan habitualmente un hallazgo casual. Pueden progresar paulatinamente generando gran deterioro campimétrico. No existe un tratamiento eficaz. Solo en casos donde aparezca neovascularización asociada, puede estar indicado el tratamiento con fármacos antiangiogénicos.