iNOS is essential to maintain a protective Th1/Th2 response and the production of cytokines/chemokines against Schistosoma japonicum infection in rats.

Humans and a wide range of mammals are generally susceptible to Schistosoma infection, while some rodents such as Rattus rats and Microtus spp are not. We previously demonstrated that inherent high expression levels of nitric oxide (NO), produced by inducible nitric oxide synthase (iNOS), plays an important role in blocking the growth and development of Schistosoma japonicum in wild-type rats. However, the potential regulatory effects of NO on the immune system and immune response to S. japonicum infection in rats are still unknown. In this study, we used iNOS-knockout (KO) rats to determine the role of iNOS-derived NO in the immune system and immunopathological responses to S. japonicum infection in rats. Our data showed that iNOS deficiency led to weakened immune activity against S. japonicum infection. This was characterized by the impaired T cell responses and a significant decrease in S. japonicum-elicited Th2/Th1 responses and cytokine and chemokine-producing capability in the infected iNOS-KO rats. Unlike iNOS-KO mice, Th1-associated cytokines were also decreased in the absence of iNOS in rats. In addition, a profile of pro-inflammatory and pro-fibrogenic cytokines was detected in serum associated with iNOS deficiency. The alterations in immune responses and cytokine patterns were correlated with a slower clearance of parasites, exacerbated granuloma formation, and fibrosis following S. japonicum infection in iNOS-KO rats. Furthermore, we have provided direct evidence that high levels of NO in rats can promote the development of pulmonary fibrosis induced by egg antigens of S. japonicum, but not inflammation, which was negatively correlated with the expression of TGF-ß3. These studies are the first description of the immunological and pathological profiles in iNOS-KO rats infected with S. japonicum and demonstrate key differences between the responses found in mice. Our results significantly enhance our understanding of the immunoregulatory effects of NO on defensive and immunopathological responses in rats and the broader nature of resistance to pathogens such as S. japonicum.

Inhibition of inducible nitric oxide synthase protects against the deleterious effects of sub-lethal sepsis and ethanol in the cardiorenal system.

We tested the hypothesis that ethanol would aggravate the deleterious effects of sub-lethal cecal ligation and puncture (SL-CLP) sepsis in the cardiorenal system and that inhibition of inducible nitric oxide synthase (iNOS) would prevent such response. Male C57BL/6 mice were treated with ethanol for 12 weeks. One hour before SL-CLP surgery, mice were treated with N6-(1-iminoethyl)-lysine (L-NIL, 5 mg/kg, i.p.), a selective inhibitor of iNOS. A second dose of L-NIL was administered 24 h after SL-CLP surgery. Mice were killed 48 h post surgery and the blood, the renal cortex, and the left ventricle (LV) were collected for biochemical analysis. L-NIL attenuated the increase in serum creatinine levels induced by ethanol, but not by SL-CLP. Ethanol, but not SL-CLP, increased creatine kinase (CK)-MB activity and L-NIL did not prevent this response. In the renal cortex, L-NIL prevented the redox imbalance induced by ethanol and SL-CLP. Inhibition of iNOS also decreased lipoperoxidation induced by ethanol and SL-CLP in the LV. L-NIL prevented the increase of pro-inflammatory cytokines and reactive oxygen species induced by ethanol and (or) SL-CLP in the cardiorenal system, suggesting that iNOS modulated some of the molecular mechanisms that underlie the deleterious effects of both conditions in the cardiorenal system.

Transforming growth factor-ß1 and inducible nitric oxide synthase signaling were involved in effects of prostaglandin E2 on progression of lower limb varicose veins.

OBJECTIVE: The vital pathogenesis of varicose veins includes remodeling of the extracellular matrix and decreased vascular tone. Prostaglandin E2 (PGE2), a small molecule substance and inflammatory medium that belongs to the arachidonic acid derivatives, has the capacity to influence the expression of metalloproteinase and the vascular tone of the venous wall. The purpose of the present study was to investigate the role of PGE2 in the development of varicose veins in lower limbs. METHODS: The collected venous specimens were analyzed using hematoxylin and eosin, Masson's trichrome, and immunohistochemical staining. Transforming growth factor (TGF)-ß1, PGE2, CD31, and α-smooth muscle actin antibody were used to detect the expression and distribution of these proteins. The effect of PGE2 on the proliferation, migration, and tube formation capacity of human umbilical vein endothelial cells (HUVECs) was detected in vitro. The effect of TGF-ß1 on the expression of PGE2 and matrix metalloproteinases (MMPs) was assessed using Western blotting. Quantitative reverse transcription polymerase chain reaction was used to evaluate the effect of PGE2 on the expression of nitric oxide synthase (NOS) and other genes. RESULTS: The expression of PGE2 and TGF-ß1 in varicose veins was upregulated in the media tunica and intima tunica, and a strong positive correlation was found between PGE2 and TGF-ß1 expression in both varicose veins (95% confidence interval, 0.5207-0.9582; R = 0.848; P = .0005) and normal veins (95% confidence interval, 0.2530-0.8532; R = 0.643; P = .003). PGE2 promoted the migration and tube formation ability of HUVECs. Moreover, PGE2 also upregulated the expression of MMP-1 and TGF-ß1 in HUVECs and increased the mRNA level of inducible NOS. CONCLUSIONS: PGE2 can affect the remodeling of the extracellular matrix and reduce the elasticity of the vascular walls by promoting the synthesis of TGF-ß1 and MMP-1. PGE2 can also reduce the tension of the great saphenous vein by promoting the expression of inducible NOS, thus aggravating the blood stasis.

IFNγ and iNOS-Mediated Alterations in the Bone Marrow and Thymus and Its Impact on Mycobacterium avium-Induced Thymic Atrophy.

Disseminated infection with the high virulence strain of Mycobacterium avium 25291 leads to progressive thymic atrophy. We previously showed that M. avium-induced thymic atrophy results from increased glucocorticoid levels that synergize with nitric oxide (NO) produced by interferon gamma (IFNγ) activated macrophages. Where and how these mediators act is not understood. We hypothesized that IFNγ and NO promote thymic atrophy through their effects on bone marrow (BM) T cell precursors and T cell differentiation in the thymus. We show that M. avium infection cause a reduction in the percentage and number of common lymphoid progenitors (CLP). Additionally, BM precursors from infected mice show an overall impaired ability to reconstitute thymi of RAGKO mice, in part due to IFNγ. Thymi from infected mice present an IFNγ and NO-driven inflammation. When transplanted under the kidney capsule of uninfected mice, thymi from infected mice are unable to sustain T cell differentiation. Finally, we observed increased thymocyte death via apoptosis after infection, independent of both IFNγ and iNOS; and a decrease on active caspase-3 positive thymocytes, which is not observed in the absence of iNOS expression. Together our data suggests that M. avium-induced thymic atrophy results from a combination of defects mediated by IFNγ and NO, including alterations in the BM T cell precursors, the thymic structure and the thymocyte differentiation.

Inhibition of mitochondrial fission and iNOS in the dorsal vagal complex protects from overeating and weight gain.

OBJECTIVES: The dorsal vagal complex (DVC) senses insulin and controls glucose homeostasis, feeding behaviour and body weight. Three-days of high-fat diet (HFD) in rats are sufficient to induce insulin resistance in the DVC and impair its ability to regulate feeding behaviour. HFD-feeding is associated with increased dynamin-related protein 1 (Drp1)-dependent mitochondrial fission in the DVC. We investigated the effects that altered Drp1 activity in the DVC has on feeding behaviour. Additionally, we aimed to uncover the molecular events and the neuronal cell populations associated with DVC insulin sensing and resistance. METHODS: Eight-week-old male Sprague Dawley rats received DVC stereotactic surgery for brain infusion to facilitate the localised administration of insulin or viruses to express mutated forms of Drp1 or to knockdown inducible nitric oxide synthase (iNOS) in the NTS of the DVC. High-Fat diet feeding was used to cause insulin resistance and obesity. RESULTS: We showed that Drp1 activation in the DVC increases weight gain in rats and Drp1 inhibition in HFD-fed rats reduced food intake, weight gain and adipose tissue. Rats expressing active Drp1 in the DVC had higher levels of iNOS and knockdown of DVC iNOS in HFD-fed rats led to a reduction of food intake, weight gain and adipose tissue. Finally, inhibiting mitochondrial fission in DVC astrocytes was sufficient to protect rats from HFD-dependent insulin resistance, hyperphagia, weight gain and fat deposition. CONCLUSION: We uncovered new molecular and cellular targets for brain regulation of whole-body metabolism, which could inform new strategies to combat obesity and diabetes.

Inducible nitric oxide synthase plays a role in depression- and anxiety-like behaviors chronically induced by lipopolysaccharide in rats: Evidence from inflammation and oxidative stress.

OBJECTIVE: The effects of aminoguanidine (AG) were investigated in a rat model of lipopolysaccharide (LPS)-induced anxiety- and depression-like behaviors. MATERIALS AND METHODS: The animals were allocated to five groups (n = 10 in each) and treated by: (1) saline as a control group, (2) LPS 1 mg/kg injected two hours before behavioral tests, (3-5) AG 50, 100 or 150 mg/kg before LPS. The open-field test (OFT), elevated plus maze test (EPT), and forced swimming (FS) tests were performed. The brains and blood were then collected to examine oxidative stress and inflammation criteria. RESULTS: LPS increased the immobility while decreased the active time in the FS test. In EPT, LPS decreased the time spent in the open arms, whereas it increased the time spent in the closed arms. In OFT, LPS decreased the time spent in the central zone compared with the controls. A higher dose of selenium improved the performances of the rats in behavioral tests. LPS injection also increased malondialdehyde (MDA) while it decreased thiol, superoxide dismutase (SOD), and catalase. LPS also increased interleukin (IL)-6 and tumor necrosis factor-alpha (TNF-α), but decreased IL-10 in the LPS group. AG protected the brain from inflammation and oxidative damage. CONCLUSION: It was demonstrated that AG improves the behaviors of depression and anxiety in a rat model of LPS-induced anxiety- and depression-like behaviors. Moreover, the effects of AG were accompanied by improved inflammation and oxidative damage biomarkers in brain tissues.

CpG Oligonucleotides Protect Mice From Alphavirus Encephalitis: Role of NK Cells, Interferons, and TNF.

Arboviruses including alphavirus are responsible for most emerging infectious diseases worldwide. Recent outbreaks of chikungunya virus serve as a stark reminder to their pathogenic potential. There are no vaccines or therapeutics currently available to contain alphavirus outbreaks. In this study we evaluated the effect of immunomodulatory CpG ODN on the clinical progression of neurotropic Sindbis virus infection. Neonatal C57Bl-6 mice challenged with Sindbis virus AR339 (25 PFU Subcutaneous) infect neurons in the CNS leading to the development of ataxia, seizures, paralysis, and death. We show that systemic administration of CpG ODN modulates the cytokine and chemokine gene expression levels in the CNS and ultimately protects neonatal mice from lethal neurotropic infection. The protection conferred by CpG ODN is controlled by innate immune response and T and B cells were dispensable. Further, protection required Type I, Type II interferons, and TNF as well as functional NK cells, but did not involve iNOS. This study confirms that administration of innate immune modulators can be used as a strategy to boost host innate immune responses and protect against neurotropic viruses reducing their pathogenic footprint.

Redox lipid reprogramming commands susceptibility of macrophages and microglia to ferroptotic death.

Ferroptotic death is the penalty for losing control over three processes-iron metabolism, lipid peroxidation and thiol regulation-that are common in the pro-inflammatory environment where professional phagocytes fulfill their functions and yet survive. We hypothesized that redox reprogramming of 15-lipoxygenase (15-LOX) during the generation of pro-ferroptotic signal 15-hydroperoxy-eicosa-tetra-enoyl-phosphatidylethanolamine (15-HpETE-PE) modulates ferroptotic endurance. Here, we have discovered that inducible nitric oxide synthase (iNOS)/NO•-enrichment of activated M1 (but not alternatively activated M2) macrophages/microglia modulates susceptibility to ferroptosis. Genetic or pharmacologic depletion/inactivation of iNOS confers sensitivity on M1 cells, whereas NO• donors empower resistance of M2 cells to ferroptosis. In vivo, M1 phagocytes, in comparison to M2 phagocytes, exert higher resistance to pharmacologically induced ferroptosis. This resistance is diminished in iNOS-deficient cells in the pro-inflammatory conditions of brain trauma or the tumour microenvironment. The nitroxygenation of eicosatetraenoyl (ETE)-PE intermediates and oxidatively truncated species by NO• donors and/or suppression of NO• production by iNOS inhibitors represent a novel redox mechanism of regulation of ferroptosis in pro-inflammatory conditions.

Potential role of NF-κB pathway in the immuno-inflammatory responses during human cystic echinococcosis.

Cystic echinococcosis (CE) induces in the human host innate and adaptive immune response that plays an important role in controlling the immunopathogenesis. Due to the crucial role of nuclear factor kappa B (NF-κB) in regulating immuno-inflammatory processes, we investigated its potential contribution in systemic and local immuno-inflammatory responses in primary CE patients and relapsed patients. The expression of NF-κB and inducible nitric oxide synthase (iNOS) was analyzed in peripheral blood mononuclear cells (PBMC) as well as in pericystic layer of pulmonary hydatid cysts from Algerian primary CE patients and relapsed patients. Tumor necrosis factor alpha (TNF-α) and nitric oxide (NO) production was evaluated in plasma samples. Our results showed high iNOS and NF-κB expression in both PBMCs and pericystic histiocytes from primary CE patients. In addition, substantial amounts of systemic NO and TNF-α were detected in the same patients. Remarkably, relapsed patients exhibited a low NF-κB and iNOS expression associated with low amounts of plasmatic TNF-α and NO. Collectively, NF-κB/iNOS pathway is involved in the host defense mechanisms at the systemic and local level during primary CE. Our results indicate that the inhibition of this pathway in relapsed patients will attenuate protective immunity and promote parasite escape. This study allowed to identify a novel predictive biomarkers of hydatidosis.

Inducible Nitric Oxide Synthase is required for parasite restriction and inflammatory modulation during Neospora caninum infection.

Neospora caninum infection is an important cause of neuromuscular disease in dogs and abortion in cattle, leading to significant economic losses in beef and dairy industries. The protective immunity against apicomplexan parasites, specifically Toxoplasma gondii and N. caninum, is typically achieved by inducing an IL-12-driven Th1 immune response. IL-12 stimulates IFN-γ production, which activates Inducible Nitric Oxide Synthase (iNOS) and promotes consequent Nitric Oxide (NO) synthesis, classically described as one of the main effector mechanisms for parasite elimination. Here, we aimed to evaluate the role played by iNOS during N. caninum infection. Our results show that N. caninum infection in C57BL/6 wild type (WT) mice induce NO production in vivo and in vitro. In agreement, iNOS deficient mice, as well as WT mice treated with iNOS inhibitor aminoguanidine, succumbed during acute infection with a dose lethal to 50 % of the WT mice, and presented significant increase in parasite load when submitted to sub-lethal infection protocols. Interestingly, the lack of control of parasite proliferation observed in iNOS-/- mice was associated with notable CNS inflammation and increased production of the main systemic proinflammatory cytokines (IL-12, IFN-γ, IL-6, TNF and IL-17A). Taken together, our findings show that iNOS plays an important role in restricting N. caninum replication, while also modulates the inflammatory process induced by the infection.

Comparing the preventive effect of sodium hydrosulfide, leptin, and curcumin against L-arginine induced acute pancreatitis in rats: role of corticosterone and inducible nitric oxide synthase.

OBJECTIVES: Acute pancreatitis (AP) is a life-threatening condition. Using antioxidants in AP is insufficient and conflicting. Therefore, this study compared the effect of hydrogen sulfide (H2S) donor, sodium hydrosulfide (NaHS), leptin or curcumin pretreatment on AP induced by L-arginine. METHODS: Forty adult male rats were used and classified into: 1) control; 2) AP group [each rat was intraperitoneally (i.p.) injected with 2 doses of L-arginine of 250 mg/100 g body weight (b.w.) with an interval of 1 h]; 3) NaHS+AP group (each rat was i.p. injected with 10 mg/kg b.w. of NaHS 1 h before induction of AP); 4) leptin+AP group (each rat was pretreated with 10 µg/kg b.w. of leptin 30 min before induction of AP; and 5) curcumin+AP group (in which rats were i.p. injected with 150 mg/kg b.w. of curcumin 30 min before induction of AP). Serum amylase, lipase, nitric oxide (NO), tumor necrosis factor alpha (TNF-α), and corticosterone (CORT) levels were assayed. In addition, pancreatic tissues were obtained for histopathological examination and malondialde-hyde (MDA), total antioxidant capacity (TAC), and inducible nitric oxide synthase (iNOS) levels were measured. RESULTS: All AP treated groups showed significant decrease in serum levels of pancreatic enzymes, NO, and TNF-α, and pancreatic MDA and iNOS levels, while TAC levels were significantly increased. NaHS caused more limitation of inflammation than leptin and curcumin by affecting iNOS. Leptin was more potent than curcumin due to the stimulatory effect of leptin on glucocorticoid release to counteract inflammation. CONCLUSIONS: NaHS was more effective in AP amelioration than the leptin and curcumin.

Regulation of mycobacterial infection by macrophage Gch1 and tetrahydrobiopterin.

Inducible nitric oxide synthase (iNOS) plays a crucial role in controlling growth of Mycobacterium tuberculosis (M.tb), presumably via nitric oxide (NO) mediated killing. Here we show that leukocyte-specific deficiency of NO production, through targeted loss of the iNOS cofactor tetrahydrobiopterin (BH4), results in enhanced control of M.tb infection; by contrast, loss of iNOS renders mice susceptible to M.tb. By comparing two complementary NO-deficient models, Nos2-/- mice and BH4 deficient Gch1fl/flTie2cre mice, we uncover NO-independent mechanisms of anti-mycobacterial immunity. In both murine and human leukocytes, decreased Gch1 expression correlates with enhanced cell-intrinsic control of mycobacterial infection in vitro. Gene expression analysis reveals that Gch1 deficient macrophages have altered inflammatory response, lysosomal function, cell survival and cellular metabolism, thereby enhancing the control of bacterial infection. Our data thus highlight the importance of the NO-independent functions of Nos2 and Gch1 in mycobacterial control.

Interferon-ß inhibits inflammatory responses mediators via suppression of iNOS signaling pathway in PBMCs from patients with primary Sjögren's syndrome.

BACKGROUND: Primary Sjögren's syndrome (pSS) represents a chronic, systemic autoimmune disorder, characterized by lymphocytic infiltration of exocrine glands, inducing compromised secretory function and tissue destruction. Increasing evidence had revealed that inflammatory mediators, such as nitric oxide (NO) and pro-inflammatory cytokines, are critical in the development and perpetuation of pSS systemic manifestations. In our current study, we aimed to investigate the ex vivo immunomodulatory effect of interferon (IFN)-ß on iNOS expression, as well as on pro-inflammatory (tumor necrosis factor (TNF)-α, interleukin (IL)-6) and immunoregulatory (IL-10) cytokine production. Furthermore, we examined potential associations between the influence of IFN-ß treatment on NO production, and pSS clinical and serological manifestations. METHODS: In 41 pSS patients documented for their clinical and serological features, NO and cytokines levels were measured by the Griess method and enzyme-linked immunosorbent assay, respectively. Inducible nitric oxide synthase expression was analyzed by fluorescence immunostaining assay, using peripheral blood mononuclear cells (PBMCs) isolated from healthy controls and pSS patients. RESULTS: Our results revealed a strong down-modulating effect of IFN-ß in the secretion of pro-inflammatory mediators including TNF-α, IL-6, and NO production. Interestingly, IFN-ß exerts an increase in IL-10 levels. The most suppressive effect exerted by IFN-ß on NO production was importantly reported for patients with neurological manifestation. This immunomodulatory effect of IFN-ß on NO production is highly related to the decrease of inducible nitric oxide synthase (iNOS) expression. CONCLUSION: Our findings highlight a consistent ex vivo inhibitory effect of IFN-ß on pro-inflammatory cytokine production and NO pathway in pSS patients. Our data suggest that IFN-ß could represent a potential candidate for targeting inflammation during pSS.

Extra-Virgin Olive Oil with Natural Phenolic Content Exerts an Anti-Inflammatory Effect in Adipose Tissue and Attenuates the Severity of Atherosclerotic Lesions in Ldlr-/-.Leiden Mice.

SCOPE: The present study investigates the effect of olive oils with different phenolic content in high-fat diets (HFDs) on hypertrophy and inflammation in adipose tissue and associated atherosclerosis, in the context of obesity. METHODS AND RESULTS: Ldlr-/-.Leiden mice were fed three different HFDs for 32 weeks and were compared with mice fed the standard low-fat diet (LFD). The different fats provided in the HFDs were lard (HFD-L), extra-virgin olive oil (EVOO; 79 mg kg-1 of phenolic compounds, HFD-EVOO), or EVOO rich in phenolic compounds (OL, 444 mg kg-1 of phenolic compounds, HFD-OL). All HFD-fed mice became obese, but only HFD-L-induced adipocyte hypertrophy. HFD-EVOO mice exhibited the greatest levels of Adiponectin in adipose tissue and presented atherosclerotic lesions similar to the LFD group, with a very low count of monocyte/macrophage compared with HFD-L and HFD-OL mice. Enrichment of the phenolic content of olive oil reduced the secretion of nitrites/nitrates in the aorta, but atherosclerosis was not attenuated in HFD-OL mice compared to other HFD mice. CONCLUSION: Consumption of olive oil with a natural content of phenolic compounds attenuates adipose tissue hypertrophy and inflammation and exerts antiatherosclerotic effects in mice. A higher phenolic content of olive oil did not provide further benefits in the prevention of atherosclerosis.

Inducible nitric oxide synthase during the late phase of sepsis is associated with hypothermia and immune cell migration.

Hypothermia is a significant sign of sepsis, which is associated with poor prognosis, but few mechanisms underlying the regulation of hypothermia are known. Inducible nitric oxide synthase (iNOS) is a key inflammatory mediator of sepsis. However, the therapeutic benefit of iNOS inhibition in sepsis is still controversial, and requires elucidation in an accurate model system. In this study, wild-type (WT) mice showed temperature drops in a biphasic manner at the early and late phase of sepsis, and all mice died within 48 h of sepsis. In contrast, iNOS-knockout (KO) mice never showed the second temperature drop and exhibited improved mortality. Plasma nitric oxide (NO) levels of WT mice increased in the late phase of sepsis and correlated to hypothermia. The results indicate that iNOS-derived NO during the late phase of sepsis caused vasodilation-induced hypothermia and a lethal hypodynamic state. The expression of the iNOS mRNA was high in the lung of WT mice with sepsis, which reflects the pathology of acute respiratory distress syndrome (ARDS). We obtained the results in a modified keyhole-type cecal ligation and puncture model of septic shock induced by minimally invasive surgery. In this accurate and reproducible model system, we transplanted the bone marrow cells of GFP transgenic mice into WT and iNOS-KO mice, and evaluated the role of increased pulmonary iNOS expression in cell migration during the late phase of sepsis. We also investigated the quantity and type of bone marrow-derived cells (BMDCs) in the lung. The number of BMDCs in the lung of iNOS-KO mice was less than that in the lung of WT mice. The major BMDCs populations were CD11b-positive, iNOS-negative cells in WT mice, and Gr-1-positive cells in iNOS-KO mice that expressed iNOS. These results suggest that sustained hypothermia may be a beneficial guide for future iNOS-targeted therapy of sepsis, and that iNOS modulated the migratory efficiency and cell type of BMDCs in septic ARDS.

Oral submucous fibrosis: an etiological dilemma.

OBJECTIVE: Oral Submucous Fibrosis (OSF), is a well-recognized, oral potentially malignant disorder predominantly affecting the South- Asian countries. OSF causes unique generalized fibrosis of the submucosal oral soft tissues, resulting in marked rigidity of the oral mucosa leading to progressive inability to open the mouth, rigidity of lips and difficulty in protruding the tongue. In this review we have discussed the multifactorial etiology of this potentially malignant disorder, including Chillies, Nutritional Deficiencies, Inducible nitric oxide synthsis (iNOS), genetic and immunological predisposition; and most importantly the role of areca nut and the effect of copper content in it.

The role of nitric oxide in melanoma.

Nitric oxide (NO) is a small gaseous signaling molecule that mediates its effects in melanoma through free radical formation and enzymatic processes. Investigations have demonstrated multiple roles for NO in melanoma pathology via immune surveillance, apoptosis, angiogenesis, melanogenesis, and on the melanoma cell itself. In general, elevated levels of NO prognosticate a poor outcome for melanoma patients. However, there are processes where the relative concentration of NO in different environments may also serve to limit melanoma proliferation. This review serves to outline the roles of NO in melanoma development and proliferation. As demonstrated by multiple in vivo murine models and observations from human tissue, NO may promote melanoma formation and proliferation through its interaction via inhibitory immune cells, inhibition of apoptosis, stimulation of pro-tumorigenic cytokines, activation of tumor associated macrophages, alteration of angiogenic processes, and stimulation of melanoma formation itself.

Mycobacterium tuberculosis is protected from NADPH oxidase and LC3-associated phagocytosis by the LCP protein CpsA.

Mycobacterium tuberculosis' success as a pathogen comes from its ability to evade degradation by macrophages. Normally macrophages clear microorganisms that activate pathogen-recognition receptors (PRRs) through a lysosomal-trafficking pathway called "LC3-associated phagocytosis" (LAP). Although Mtuberculosis activates numerous PRRs, for reasons that are poorly understood LAP does not substantially contribute to Mtuberculosis control. LAP depends upon reactive oxygen species (ROS) generated by NADPH oxidase, but Mtuberculosis fails to generate a robust oxidative response. Here, we show that CpsA, a LytR-CpsA-Psr (LCP) domain-containing protein, is required for Mtuberculosis to evade killing by NADPH oxidase and LAP. Unlike phagosomes containing wild-type bacilli, phagosomes containing the ΔcpsA mutant recruited NADPH oxidase, produced ROS, associated with LC3, and matured into antibacterial lysosomes. Moreover, CpsA was sufficient to impair NADPH oxidase recruitment to fungal particles that are normally cleared by LAP. Intracellular survival of the ΔcpsA mutant was largely restored in macrophages missing LAP components (Nox2, Rubicon, Beclin, Atg5, Atg7, or Atg16L1) but not in macrophages defective in a related, canonical autophagy pathway (Atg14, Ulk1, or cGAS). The ΔcpsA mutant was highly impaired in vivo, and its growth was partially restored in mice deficient in NADPH oxidase, Atg5, or Atg7, demonstrating that CpsA makes a significant contribution to the resistance of Mtuberculosis to NADPH oxidase and LC3 trafficking in vivo. Overall, our findings reveal an essential role of CpsA in innate immune evasion and suggest that LCP proteins have functions beyond their previously known role in cell-wall metabolism.

Mechanism of salutary effects of melatonin-mediated liver protection after trauma-hemorrhage: p38 MAPK-dependent iNOS/HIF-1α pathway.

Although melatonin attenuates the increases in inflammatory mediators and reduces organ injury during trauma-hemorrhage, the mechanisms remain unclear. This study explored whether melatonin prevents liver injury after trauma-hemorrhage through the p38 mitogen-activated protein kinase (MAPK)-dependent, inducible nitrite oxide (iNOS)/hypoxia-inducible factor (HIF)-1α pathway. After a 5-cm midline laparotomy, male rats underwent hemorrhagic shock (mean blood pressure ~40 mmHg for 90 min) followed by fluid resuscitation. At the onset of resuscitation, rats were treated with vehicle, melatonin (2 mg/kg), melatonin plus p38 MAPK inhibitor SB203580 (2 mg/kg), or melatonin plus the melatonin receptor antagonist luzindole (2.5 mg/kg). At 2 h after trauma-hemorrhage, histopathology score of liver injury, liver tissue myeloperoxidase activity, malondialdehyde, adenosine triphosphate, serum alanine aminotransferase, and asparate aminotransferase levels were significantly increased compared with sham-operated control. Trauma-hemorrhage resulted in a significant decrease in the p38 MAPK activation compared with that in the sham-treated animals. Administration of melatonin after trauma-hemorrhage normalized liver p38 MAPK phosphorylation and iNOS and HIF-1α expression and attenuated cleaved caspase 3 and receptor interacting protein kinase-1 levels. Coadministration of SB203580 or luzindole abolished the melatonin-mediated attenuation of the trauma-hemorrhage-induced increase of iNOS/HIF-1α protein expression and liver injury markers. Taken together, our results suggest that melatonin prevents trauma-hemorrhage-induced liver injury in rats, at least in part, through melatonin receptor-related, p38 MAPK-dependent iNOS/HIF-1α pathway.NEW & NOTEWORTHY Trauma-hemorrhage resulted in a significant decrease in liver p38 MAPK activation and increase in nitrite oxide synthase (iNOS) and hypoxia-inducible factor (HIF)-1α expression. Administration of melatonin after trauma-hemorrhage normalized liver p38 MAPK phosphorylation and iNOS and HIF-1α expression, which was abolished by coadministration of SB203580 or luzindole. Melatonin prevents trauma-hemorrhage-induced liver injury in rats via the melatonin receptor-related, p38 MAPK-dependent iNOS/HIF-1α pathway.

Effects of soybean isoflavone on intestinal antioxidant capacity and cytokines in young piglets fed oxidized fish oil.

To investigate the effect of glycitein, a synthetic soybean isoflavone (ISF), on the intestinal antioxidant capacity, morphology, and cytokine content in young piglets fed oxidized fish oil, 72 4-d-old male piglets were assigned to three treatments. The control group was fed a basal diet containing fresh fish oil, and the other two groups received the same diet except for the substitution with the same dosage of oxidized fish oil alone or with ISF (oxidized fish oil plus ISF). After 21 d of feeding, supplementation of oxidized fish oil increased the levels of malondialdehyde (MDA), oxidized glutathione (GSSG), interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α), interleukin-2 (IL-2), nuclear factor κ B (NF-κB), inducible nitric oxide synthase (iNOS), NO, and Caspase-3 in jejunal mucosa, and decreased the villous height in duodenum and the levels of secretory immunoglobulin A (sIgA) and IL-4 in the jejunal mucosa compared with supplementation with fresh oil. The addition of oxidized fish oil plus ISF partially alleviated this negative effect. The addition of oxidized fish oil plus ISF increased the villous height and levels of sIgA and IL-4 in jejunal mucosa, but decreased the levels of IL-1ß and IL-2 in jejunal mucosa (P<0.05) compared with oxidized fish oil. Collectively, these results show that dietary supplementation of ISF could partly alleviate the negative effect of oxidized fish oil by improving the intestinal morphology as well as the antioxidant capacity and immune function in young piglets.