Tear Film Immunological Profile in Patients with Ocular Graft versus Host Disease.

PURPOSE: To analyze and compare the tear immunological profile in ocular GVHD (oGVHD) patients with that in non-oGVHD patients and to correlate them with ocular surface parameters based on the International Chronic Ocular GVHD Consensus Group (ICCGVHD) diagnostic criteria. METHODS: Tear samples from 20 individuals who underwent allo-hematopoietic stem cell transplantation and were grouped according the presence or absence of oGVHD were analyzed using Bio-Plex assay. RESULTS: IL-8 and MIP-1α levels were significantly higher in tears from oGVHD patients compared with those in tears from non-oGVHD patients (p<0.001 and p=0.001, respectively). Tear IL-8 levels correlated significantly with OSDI criteria (ρ=0.5159, p=0.001), ocular hyperemia (ρ=0.469, p=0.002), and corneal staining (ρ=0.339, p=0.032), whereas tear Mip-1α levels correlated with OSDI score (ρ=0.358, p=0.023). CONCLUSION: We demonstrated higher tear levels of IL-8 and MIP-1α in oGVHD patients and significant correlations between theses cytokines and ocular surface parameters based on the ICCGVHDCG criteria.

The dual effect of acetate on microglial TNF-α production.

INTRODUCTION: Short-Chain Fatty Acids (SCFA) are products of intestinal microbial metabolism that can reach the brain and alter microglia in health and disease contexts. However, data are conflicting on the effect of acetate, the most abundant SCFA in the blood, in these cells. OBJECTIVE: The authors aimed to investigate acetate as a modulator of the inflammatory response in microglia stimulated with LPS. METHOD: The authors used an immortalized cell line, C8-B4, and primary cells for in vitro treatments with acetate and LPS. Cell viability was analyzed by MTT, cytokine by RT-PCR, ELISA, and flow cytometry. The authors also performed in vivo and in silico analyses to study the role of acetate and the TNF-α contribution to the development of Experimental Autoimmune Encephalomyelitis (EAE). RESULTS: Acetate co-administered with LPS was able to exacerbate the production of pro-inflammatory cytokines at gene and protein levels in cell lines and primary culture of microglia. However, the same effects were not observed when acetate was administered alone or as pretreatment, prior to the LPS stimulus. Additionally, pharmacological inhibition of histone deacetylase concomitantly with acetate and LPS led to decreased TNF-α production. In silico analysis showed a crucial role of the TNF-α pathway in EAE development. Moreover, acetate administration in vivo during the initial phase of EAE led to a better disease outcome and reduced TNF-α production. CONCLUSION: Treatment with acetate was able to promote the production of TNF-α in a concomitant LPS stimulus of microglia. However, the immune modulation of microglia by acetate pretreatment may be a component in the generation of future therapies for neurodegenerative diseases.

The dual effect of acetate on microglial TNF-α production

Abstract Introduction: Short-Chain Fatty Acids (SCFA) are products of intestinal microbial metabolism that can reach the brain and alter microglia in health and disease contexts. However, data are conflicting on the effect of acetate, the most abundant SCFA in the blood, in these cells. Objective: The authors aimed to investigate acetate as a modulator of the inflammatory response in microglia stimulated with LPS. Method: The authors used an immortalized cell line, C8-B4, and primary cells for in vitro treatments with acetate and LPS. Cell viability was analyzed by MTT, cytokine by RT-PCR, ELISA, and flow cytometry. The authors also performed in vivo and in silico analyses to study the role of acetate and the TNF-α contribution to the development of Experimental Autoimmune Encephalomyelitis (EAE). Results: Acetate co-administered with LPS was able to exacerbate the production of pro-inflammatory cytokines at gene and protein levels in cell lines and primary culture of microglia. However, the same effects were not observed when acetate was administered alone or as pretreatment, prior to the LPS stimulus. Additionally, pharmacological inhibition of histone deacetylase concomitantly with acetate and LPS led to decreased TNF-α production. In silico analysis showed a crucial role of the TNF-α pathway in EAE development. Moreover, acetate administration in vivo during the initial phase of EAE led to a better disease outcome and reduced TNF-α production. Conclusion: Treatment with acetate was able to promote the production of TNF-α in a concomitant LPS stimulus of microglia. However, the immune modulation of microglia by acetate pretreatment may be a component in the generation of future therapies for neurodegenerative diseases. HIGHLIGHTS Acetate was able to exacerbate the production of TNF-α in microglia. Acetate administered as pre-treatment to LPS acts as an anti-inflammatory. Histone deacetylase decreased TNF-α production in Acetate- and LPS-treated cells. Depending on the time of administration, Acetate modulates microglia's activation. Acetate may threaten neurodegenerative and neuropsychiatric diseases.

Acute Kidney Injury Model Induced by Cisplatin in Adult Zebrafish.

Cisplatin is commonly used as chemotherapy. Although it has positive effects in cancer-treated individuals, cisplatin can easily accumulate in the kidney due to its low molecular weight. Such accumulation causes the death of tubular cells and can induce the development of Acute Kidney Injury (AKI), which is characterized by a quick decrease in kidney function, tissue damage, and immune cells infiltration. If administered in specific doses cisplatin can be a useful tool as an AKI inducer in animal models. The zebrafish has appeared as an interesting model to study renal function, kidney regeneration, and injury, as renal structures conserve functional similarities with mammals. Adult zebrafish injected with cisplatin shows decreased survival, kidney cell death, and increased inflammation markers after 24 h post-injection (hpi). In this model, immune cells infiltration and cell death can be assessed by flow cytometry and TUNEL assay. This protocol describes the procedures to induce AKI in adult zebrafish by intraperitoneal cisplatin injection and subsequently demonstrates how to collect the renal tissue for flow cytometry processing and cell death TUNEL assay. These techniques will be useful to understand the effects of cisplatin as a nephrotoxic agent and will contribute to the expansion of AKI models in adult zebrafish. This model can also be used to study kidney regeneration, in the search for compounds that treat or prevent kidney damage and to study inflammation in AKI. Moreover, the methods used in this protocol will improve the characterization of tissue damage and inflammation, which are therapeutic targets in kidney-associated comorbidities.

Sensing soluble uric acid by Naip1-Nlrp3 platform.

Uric acid (UA), a product of purine nucleotide degradation able to initiate an immune response, represents a breakpoint in the evolutionary history of humans, when uricase, the enzyme required for UA cleavage, was lost. Despite being inert in human cells, UA in its soluble form (sUA) can increase the level of interleukin-1ß (IL-1ß) in murine macrophages. We, therefore, hypothesized that the recognition of sUA is achieved by the Naip1-Nlrp3 inflammasome platform. Through structural modelling predictions and transcriptome and functional analyses, we found that murine Naip1 expression in human macrophages induces IL-1ß expression, fatty acid production and an inflammation-related response upon sUA stimulation, a process reversed by the pharmacological and genetic inhibition of Nlrp3. Moreover, molecular interaction experiments showed that Naip1 directly recognizes sUA. Accordingly, Naip may be the sUA receptor lost through the human evolutionary process, and a better understanding of its recognition may lead to novel anti-hyperuricaemia therapies.

Increased lacrimal inflammatory mediators in patients with keratoconus.

Purpose: This study aimed to characterize the tear film immunologic profile in keratoconus (KC) patients compared with healthy individuals (control group) and to investigate the correlation between the tear film immunologic profile and atopy, disease severity, and disease status over time. Methods: The study involved 30 KC patients and 18 healthy individuals. Tear collection was obtained using microcapillary tubes. Tear film levels of fractalkine, granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon (IFN)-γ, interleukin (IL)-1ß, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13, IL-17A, IL-21, IL-23, interferon-inducible T-cell alpha chemoattractant (ITAC), macrophage inflammatory protein-1 alpha (MIP-1α), MIP-1ß, MIP-3α, and tumor necrosis factor (TNF)-α were detected. Keratometric measurements and topographic patterns were used to diagnose and define disease progression. Tear immunologic profiles were compared, emphasizing the presence or absence of ocular allergy. Correlations between the cytokine profile, disease severity, and disease status were also analyzed longitudinally in the KC patients. Results: Lacrimal cytokine concentrations were higher in the KC patients than they were in the controls in 14 of 21 cytokines analyzed. IL-6 was the most relevant cytokine found in KC patients, especially when associated with ocular allergy. There was no correlation between KC progression and the level of inflammatory cytokines when analyzed longitudinally. KC severity correlated with IL-6 concentration, where the more severe KC presented a higher IL-6 concentration in tears. Conclusions: Inflammatory activity seems to be involved in the pathogenesis of KC. Out of 21 cytokines, 14 were more concentrated in the tears of KC patients than healthy subjects. IL-6 was significantly higher in KC patients' tears and was related to disease severity. Disease progression did not correlate with cytokine levels when analyzed longitudinally.

Host dysbiosis negatively impacts IL-9-producing T-cell differentiation and antitumour immunity.

BACKGROUND: Host-microbiota interactions shape T-cell differentiation and promote tumour immunity. Although IL-9-producing T cells have been described as potent antitumour effectors, their role in microbiota-mediated tumour control remains unclear. METHODS: We analysed the impact of the intestinal microbiota on the differentiation of colonic lamina propria IL-9-producing T cells in germ-free and dysbiotic mice. Systemic effects of the intestinal microbiota on IL-9-producing T cells and the antitumour role of IL-9 were analysed in a model of melanoma-challenged dysbiotic mice. RESULTS: We show that germ-free mice have lower frequency of colonic lamina propria IL-9-producing T cells when compared with conventional mice, and that intestinal microbiota reconstitution restores cell frequencies. Long-term antibiotic treatment promotes host dysbiosis, diminishes intestinal IL-4 and TGF-ß gene expression, decreases the frequency of colonic lamina propria IL-9-producing T cells, increases the susceptibility to tumour development and reduces the frequency of IL-9-producing T cells in the tumour microenvironment. Faecal transplant restores intestinal microbiota diversity, and the frequency of IL-9-producing T cells in the lungs of dysbiotic animals, restraining tumour burden. Finally, recombinant IL-9 injection enhances tumour control in dysbiotic mice. CONCLUSIONS: Host-microbiota interactions are required for adequate differentiation and antitumour function of IL-9-producing T cells.

Physical exercise contributes to cisplatin-induced nephrotoxicity protection with decreased CD4+ T cells activation.

Cisplatin is a chemotherapy used to treat different types of cancer, such as testicular, bladder and head and neck. Physical exercise has been shown to improve cancer therapy and recently, it was demonstrated to be able to diminish side effects such as acute kidney injury (AKI), a common side effect in cisplatin treatment. In both cases, the modulation of inflammatory cytokines seems to be one of the mechanisms, but little is known about the immune cells in this process. Here, we investigated the role of CD4 + T cells in the AKI protection by physical exercise. We subjected C57Bl6 mice to long-term physical exercise (EX) before cisplatin treatment. Sedentary groups were used as control (CT). We confirmed that physical exercise decreased AKI by evaluating creatinine and Kim-1 levels, in the serum and kidney respectively. Analyzing the organs weight, we noticed a decrease in sedentary (CIS) and exercised (CIS-EX) cisplatin treated groups. Epididymal and brown adipose tissue weight were decreased in cisplatin treated subjects in comparison to untreated groups, as well as liver and spleen. We then investigated the profile of CD4 + T cells in the spleen and we observed increased levels of Tregs and CD4+CD25+ cells in CIS group, while CIS-EX presented similar amounts as control groups. Analyzing the kidney lymph nodes, we noticed a decrease of CD4+ cells in both CIS and CIS-EX group. However, a more activated phenotype (CD69+ and CD25+) was observed in CIS groups in comparison to CIS-EX group, as well as the presence of Tregs. We then investigated the production of cytokines by these cells and no difference among the groups was observed in cytokines production in splenic CD4 + T cells. However, a clear increase in TNF and IL-10 production was observed in CD4 + T cells from lymph nodes, while CIS-EX group presented similar levels as the control groups. We confirmed that physical exercise was able to diminish cisplatin-induced AKI with concomitant decrease in CD4 + T cell activation.

CCR2 contributes to the recruitment of monocytes and leads to kidney inflammation and fibrosis development.

Chemokines are a large family of proteins that, once associated to its receptor on leukocytes, stimulate their movement and migration from blood to tissues. Once in the tissue, immune cells trigger inflammation that, when uncontrolled, leads to fibrosis development. Among the immune cells, macrophages take a special role in fibrosis formation, since macrophage depletion reflects less collagen deposition. The majority of tissue macrophages is derived from monocytes, especially monocytes expressing the chemokine receptor CCR2. Here, we investigated the role of infiltrating CCR2+ cells in the development of fibrosis, and specifically, the dynamic of infiltration of these cells into kidneys under chronic obstructive lesion. Using liposome-encapsulated clodronate, we observed that macrophage depletion culminated in less collagen deposition and reduced chemokines milieu that were released in the damaged kidney after obstructive nephropathy. We also obstructed the kidneys of CCL3-/-, CCR2-/-, CCR4-/-, CCR5-/-, and C57BL/6 mice and we found that among all animals, CCR2-/- mice demonstrated the more robust protection, reflected by less inflammatory and Th17-related cytokines and less collagen formation. Next we evaluated the dynamic of CCR2+/rfp cell infiltration and we observed that they adhere onto the vessels at early stages of disease, culminating in increased recruitment of CCR2+/rfp cells at later stages. On the other hand, CCR2rfp/rfp animals exhibited less fibrosis formation and reduced numbers of recruited cells at later stages. We have experimentally demonstrated that inflammatory CCR2+ cells that reach the injured kidney at initial stages after tissue damage are responsible for the fibrotic pattern observed at later time points in the context of UUO.

Dectin-1 Activation Exacerbates Obesity and Insulin Resistance in the Absence of MyD88.

The underlying mechanism by which MyD88 regulates the development of obesity, metainflammation, and insulin resistance (IR) remains unknown. Global deletion of MyD88 in high-fat diet (HFD)-fed mice resulted in increased weight gain, impaired glucose homeostasis, elevated Dectin-1 expression in adipose tissue (AT), and proinflammatory CD11c+ AT macrophages (ATMs). Dectin-1 KO mice were protected from diet-induced obesity (DIO) and IR and had reduced CD11c+ AT macrophages. Dectin-1 antagonist improved glucose homeostasis and decreased CD11c+ AT macrophages in chow- and HFD-fed MyD88 KO mice. Dectin-1 agonist worsened glucose homeostasis in MyD88 KO mice. Dectin-1 expression is increased in AT from obese individuals. Together, our data indicate that Dectin-1 regulates AT inflammation by promoting CD11c+ AT macrophages in the absence of MyD88 and identify a role for Dectin-1 in chronic inflammatory states, such as obesity. This suggests that Dectin-1 may have therapeutic implications as a biomarker for metabolic dysregulation in humans.

Soluble Uric Acid Activates the NLRP3 Inflammasome.

Uric acid is a damage-associated molecular pattern (DAMP), released from ischemic tissues and dying cells which, when crystalized, is able to activate the NLRP3 inflammasome. Soluble uric acid (sUA) is found in high concentrations in the serum of great apes, and even higher in some diseases, before the appearance of crystals. In the present study, we sought to investigate whether uric acid, in the soluble form, could also activate the NLRP3 inflammasome and induce the production of IL-1ß. We monitored ROS, mitochondrial area and respiratory parameters from macrophages following sUA stimulus. We observed that sUA is released in a hypoxic environment and is able to induce IL-1ß release. This process is followed by production of mitochondrial ROS, ASC speck formation and caspase-1 activation. Nlrp3-/- macrophages presented a protected redox state, increased maximum and reserve oxygen consumption ratio (OCR) and higher VDAC protein levels when compared to WT and Myd88-/- cells. Using a disease model characterized by increased sUA levels, we observed a correlation between sUA, inflammasome activation and fibrosis. These findings suggest sUA activates the NLRP3 inflammasome. We propose that future therapeutic strategies for renal fibrosis should include strategies that block sUA or inhibit its recognition by phagocytes.

Adipose Tissue-Derived Stem Cells Reduce Acute and Chronic Kidney Damage in Mice.

Acute and chronic kidney injuries (AKI and CKI) constitute syndromes responsible for a large part of renal failures, and are today still associated with high mortality rates. Given the lack of more effective therapies, there has been intense focus on the use stem cells for organ protective and regenerative effects. Mesenchymal stem cells (MSCs) have shown great potential in the treatment of various diseases of immune character, although there is still debate on its mechanism of action. Thus, for a greater understanding of the role of MSCs, we evaluated the effect of adipose tissue-derived stem cells (AdSCs) in an experimental model of nephrotoxicity induced by folic acid (FA) in FVB mice. AdSC-treated animals displayed kidney functional improvement 24h after therapy, represented by reduced serum urea after FA. These data correlated with cell cycle regulation and immune response modulation via reduced chemokine expression and reduced neutrophil infiltrate. Long-term analyses, 4 weeks after FA, indicated that AdSC treatment reduced kidney fibrosis and chronic inflammation. These were demonstrated by reduced interstitial collagen deposition and tissue chemokine and cytokine expression. Thus, we concluded that AdSC treatment played a protective role in the framework of nephrotoxic injury via modulation of inflammation and cell cycle regulation, resulting in reduced kidney damage and functional improvement, inhibiting organ fibrosis and providing long-term immune regulation.

Simvastatin ameliorates experimental autoimmune encephalomyelitis by inhibiting Th1/Th17 response and cellular infiltration.

AIM: Experimental autoimmune encephalomyelitis (EAE) is a CD4(+)-mediated autoimmune pathology of the central nervous system (CNS) that is used as a model for the study of the human neuroinflammatory disease, multiple sclerosis. During the development of EAE, auto-reactive Th1 and Th17 CD4(+) T cells infiltrate the CNS promoting inflammatory cells recruitment, focal inflammation and tissue destruction. In this sense, statins, agents used to lower lipid levels, have recently shown to exert interesting immunomodulatory function. In fact, statins promote a bias towards a Th2 response, which ameliorates the clinical outcome of EAE. Additionally, simvastatin can inhibit Th17 differentiation. However, many other effects exerted on the immune system by statins have yet to be clarified, in particular during neuroinflammation. Thus, the aim of this study was to investigate the effects of simvastatin on the development of experimental autoimmune encephalomyelitis. METHODS: Mice were immunized with MOG(35-55) and EAE severity was assessed daily and scored using a clinical scale. Cytokine secretion by mononuclear cells infiltrating the CNS was evaluated by flow cytometry. RESULTS: Simvastatin (5 mg/kg/day) improved clinical outcome, induced an increase in TGF-ß mRNA expression and inhibited IL-6, IL-12p40, IL-12p70, RANTES and MIP-1ß secretion (p < 0.05). This was accompanied by a significant decrease in CNS inflammatory mononuclear cell infiltration, with reduced frequencies of both Th1 and Th17 cells. Simvastatin inhibited the proliferation of T lymphocytes co-cultured with primary microglial cells. CONCLUSIONS: Simvastatin treatment promotes EAE clinical amelioration by inhibiting T cell proliferation and CNS infiltration by pathogenic Th1 and Th17 cells.

The role of dexamethasone in scorpion venom-induced deregulation of sodium and water transport in rat lungs.

BACKGROUND: Severe scorpion envenomation can evolve to lung injury and, in some cases, death. The lung injury could be attributed to acute left ventricular failure and increased pulmonary vascular permeability secondary to the release of inflammatory mediators. In clinical practice, corticosteroids have been administered to reduce the early side effects of the anti-venom. We propose to study the effects of Tityus serrulatus venom and dexamethasone on pulmonary expression of sodium and water transporters, as well as on the inflammatory response. METHODS: Wistar rats were injected intraperitoneally with saline (control group), dexamethasone, and saline (2.0 mg/kg body weight-60 min before saline injection; dexamethasone + saline group), venom (T. serrulatus venom-3.8 mg/kg body weight), or dexamethasone and venom (2.0 mg/kg body weight-60 min before venom injection; dexamethasone + venom group). At 60 min after venom/saline injection, experiments were performed in ventilated and non-ventilated animals. We analyzed sodium transporters, water transporters, and Toll-like receptor 4 (TLR4) by Western blotting, macrophage infiltration by immunohistochemistry, and serum interleukin (IL) by cytokine assay. RESULTS: In the lung tissue of non-ventilated envenomed animals, protein expression of the epithelial sodium channel alpha subunit (α-ENaC) and aquaporin 5 (AQP5) were markedly downregulated whereas that of the Na-K-2Cl cotransporter (NKCC1) and TLR4 was elevated although expression of the Na,K-ATPase alpha 1 subunit was unaffected. Dexamethasone protected protein expression of α-ENaC, NKCC1, and TLR4 but not that of AQP5. We found that IL-6, IL-10, and tumor necrosis factor alpha were elevated in the venom and dexamethasone + venom groups although CD68 expression in lung tissue was elevated only in the venom group. Among the ventilated animals, both envenomed groups presented hypotension at 50 min after injection, and the arterial oxygen tension/fraction of inspired oxygen ratio was lower at 60 min than at baseline. CONCLUSIONS: Our results suggest that T. serrulatus venom and dexamethasone both regulate sodium transport in the lung and that T serrulatus venom regulates sodium transport via the TLR4 pathway.

Long-term aerobic exercise protects against cisplatin-induced nephrotoxicity by modulating the expression of IL-6 and HO-1.

Nephrotoxicity is substantial side effect for 30% of patients undergoing cancer therapy with cisplatin and may force them to change or even abandon the treatment. Studies regarding aerobic exercise have shown its efficacy for the treatment of many types of diseases and its capacity to reduce tumors. However, little is known about the impact of physical exercise on cisplatin-induced acute kidney injury (AKI). In the present study, our aim was to investigate the role of physical exercise in AKI induced by cisplatin. We submitted C57Bl6 male mice to seven weeks of chronic exercise on a training treadmill and treated them with single i.p. injection of cisplatin (20 mg/kg) in the last week. Exercise efficacy was confirmed by an increased capillary-to-fiber ratio in the gastrocnemius muscle of exercised groups (EX and CIS-EX). The group submitted to exercise before cisplatin administration (CIS-EX) exhibited less weight loss and decreased serum urea levels compared to the cisplatin group (CIS). Exercise also showed a protective role against cisplatin-induced cell death in the kidney. The CIS-EX group showed a lower inflammatory response, with less TNF and IL-10 expression in the kidney and serum. In the same group, we observed an increase of IL-6 and HO-1 expression in the kidney. Taken together, our results indicate that chronic aerobic exercise is able to attenuate AKI by inducing IL-6 and HO-1 production, which results in lower inflammatory and apoptotic profiles in the kidney.

Macrophage trafficking as key mediator of adenine-induced kidney injury.

Macrophages play a special role in the onset of several diseases, including acute and chronic kidney injuries. In this sense, tubule interstitial nephritis (TIN) represents an underestimated insult, which can be triggered by different stimuli and, in the absence of a proper regulation, can lead to fibrosis deposition. Based on this perception, we evaluated the participation of macrophage recruitment in the development of TIN. Initially, we provided adenine-enriched food to WT and searched for macrophage presence and action in the kidney. Also, a group of animals were depleted of macrophages with the clodronate liposome while receiving adenine-enriched diet. We collected blood and renal tissue from these animals and renal function, inflammation, and fibrosis were evaluated. We observed higher expression of chemokines in the kidneys of adenine-fed mice and a substantial protection when macrophages were depleted. Then, we specifically investigated the role of some key chemokines, CCR5 and CCL3, in this TIN experimental model. Interestingly, CCR5 KO and CCL3 KO animals showed less renal dysfunction and a decreased proinflammatory profile. Furthermore, in those animals, there was less profibrotic signaling. In conclusion, we can suggest that macrophage infiltration is important for the onset of renal injury in the adenine-induced TIN.