FasL Expression Research Articles

Matrix metalloproteinase 9 induces keratinocyte apoptosis through FasL/Fas pathway in diabetic wound.

Apoptosis is a mechanism to remove unwanted cells in the tissue. In diabetic wound, which is characterized by delayed healing process, excessive apoptosis is documented and plays a crucial role. Matrix metalloproteinase 9 (MMP9), which is elevated in non-healed diabetic wound, is necessary for healing process but its abnormality resulted in a delayed healing. The classical function of MMP9 is the degradation of extracellular matrix (ECM). However, there is some literature evidence that MMP9 triggers cell apoptosis. Whether the excessive MMP9 contributes to epidermis cell apoptosis in delayed healing diabetic wound and the underlying mechanisms is not clear. In this study, we aimed to explore whether MMP9 induced keratinocyte apoptosis and investigate the plausible mechanisms. Our in vitro study showed that advanced glycation end products (AGEs) induced keratinocyte apoptosis and enhanced MMP9 level. Besides, MMP9, both intra-cellular expressions and extra-cellular supplement, promoted cell apoptosis. Further, MMP9 resulted in an increased expression of FasL, other than Fas and p53. These findings identified a novel effect that MMP9 exerted in delayed diabetic wound healing, owing to a pro-apoptotic effect on keratinocyte, which was mediated by an increase of FasL expression. This study increases understanding of elevated MMP9 which is involved in diabetic wound repair and offers some insights into novel future therapies.

Long non-coding RNA XIST modulates cisplatin resistance by altering PDCD4 and Fas-Lexpressions in human nasopharyngeal carcinoma HNE1 cells in vitro

To explore the role of long non-coding RNA (lncRNA) X inactive specific transcript (XIST) in modulating cisplatin (DDP) resistance of human nasopharyngeal carcinoma cells and investigate the possible mechanism. Realtime PCR was performed to detect the expression of XIST in cisplatin-resistant human nasopharyngeal carcinoma cell line HNE1/DDP. The effects of up-regulation and down-regulation of XIST on DDP resistance, proliferation and apoptosis of HNE1/ DDP cells were assessed using MTT assay, EdU assay and flow cytometry. Western blotting was used to detect the changes in the expressions of programmed cell death 4 (PDCD4) and Fas ligand (Fas-L) proteins in the cells in response to up-regulation or down-regulation of XIST. The expression of XIST was significantly up-regulated in HNE1/DDP cells in comparison with HNE1 cells (0.57±0.06 vs 0.1±0.02, P < 0.05). Down-regulation of XIST significantly decreased while up-regulation of XIST obviously increased DDP resistance of HNE1/DDP cells (P < 0.05). Down-regulation of XIST significantly reduced the proliferation (6.17 ± 1.93 vs 16.59 ± 4.86, P < 0.05) and enhanced apoptosis [(18.04 ± 4.72)% vs (4.22 ± 1.65)%, P < 0.05], while upregulating XIST enhanced the proliferation (25.40±7.21 vs 13.16±3.95, P < 0.05) and inhibited apoptosis [(2.82±0.88)% vs (6.46± 1.75)%, P < 0.05] in HNE1/DDP cells. Down-regulation of XIST significantly increased the protein expressions of PDCD4 and Fas-L (P < 0.05) in HNE1/DDP cells, and up-regulation of XIST resulted in reverse changes in PDCD4 and Fas-L expressions (P < 0.05). XIST is up-regulated in HNE1/DDP cells, and down-regulation and up-regulation of XIST expression reduce and increase DDP resistance of the cells, respectively, possibly as a result of changes in the expressions of PDCD4 and Fas-L.

FasL on decidual macrophages mediates trophoblast apoptosis: A potential cause of recurrent miscarriage.

Macrophages can induce Fas ligand (FasL)-mediated apoptosis, and the deregulation of apoptosis is known to be associated with recurrent miscarriage (RM). The aim of the present study was to investigate the possible involvement of FasL in macrophage-mediated trophoblast apoptosis and its potential role in RM. Human decidual and placental villous tissues were collected from 81 women (21 for the RM group, 26 for the spontaneous abortion group and 34 for the control group) at 7-9 weeks of gestation. The distribution changes of macrophages and the expression of FasL on macrophages were evaluated by immunohistochemical, immunofluorescence and western blot analyses. A macrophage and trophoblast co-culture model was used to determine the effects of FasL on the apoptosis of trophoblasts. The results indicated that CD86+ macrophage populations in decidual tissues were significantly increased, accompanied by reduced CD163+ macrophages in the abortion and RM groups. Furthermore, the distribution of CD68+ macrophages was also significantly altered in specimens from the abortion and RM groups, and they were observed to have infiltrated into the trophoblast cells. In addition, elevated expression of FasL on CD68+ and CD86+ macrophages in the decidua was observed in the spontaneous abortion and RM groups of patients, and FasL was demonstrated to mediate the induction of trophoblast apoptosis by macrophages in co-culture. These results indicate that the aberration of macrophage-induced FasL-mediated apoptosis may represent one of the causes of RM.

Baicalin protects mouse testis from injury induced by heat stress.

Heat stress has been documented to reduce reproductive performance of female animals through injury to germ cells, with few studies available in male animals. The objectives of this study were to evaluate protective effects of baicalin on testicular tissue damage of mice subjected to heat stress and its related mechanisms. In this experiment, A total of forty mice were divided into four groups, including control group (C), baicalin group (B), heat stressed group (H) and heat stress with baicalin treatment (H+B) group. Morphological changes, activities of antioxidant enzymes and apoptosis-related parameters in the mice testes tissue were monitored. The results showed that the process of spermatogenesis in mice testis was impaired and the cellular apoptosis increased due to acute heat stress at 41°C. Interestingly, the tissue damage was alleviated with the significant (P < 0.05) increase in the activities of SOD, CAT and GSH-Px enzymes, decrease (P<0.05) in MDA content and number of cellular apoptosis recorded in mice of H+B group compared with those in mice from H group. In addition, the Fas, FasL and P-JNK protein expressions were significantly (P<0.05) increased; and apaf-1, caspase-3, -9 were slightly expressed in the H group, while there was no difference in Bcl-2 expression, compared with C, B and H+B groups. The above results clearly indicate that heat stress induces macroscopic/apoptotic and oxidative changes in the testicular tissue of mice; these changes are alleviated by Baicalin through increasing anti-oxidative enzyme activities and possibly through blocking Fas/FasL pathway.

Matrix metalloproteinase-7 protects against acute kidney injury by priming renal tubules for survival and regeneration

Matrix metalloproteinase-7 (MMP-7) is a secreted endopeptidase that degrades a broad range of substrates. Recent studies have identified MMP-7 as an early biomarker to predict severe acute kidney injury (AKI) and poor outcomes after cardiac surgery; however, the role of MMP-7 in the pathogenesis of AKI is unknown. In this study, we investigated the expression of MMP-7 and the impact of MMP-7 deficiency in several models of AKI. MMP-7 was induced in renal tubules following ischemia/ reperfusion injury or cisplatin administration, and in folic acid-induced AKI. MMP-7 knockout mice experienced higher mortality, elevated serum creatinine, and more severe histologic lesions after ischemic or toxic insults. Tubular apoptosis and interstitial inflammation were more prominent in MMP-7 knockout kidneys. These histologic changes were accompanied by increased expression of FasL and other components of the extrinsic apoptotic pathway, as well as increased expression of pro-inflammatory chemokines. Inarescue experiment, exogenous MMP-7 ameliorated kidney injury in MMP-7 knockout mice after ischemia/reperfusion. Invitro, MMP-7 protected tubular epithelial cells against apoptosis by directly degrading FasL. In isolated tubules exvivo, MMP-7 promoted cell proliferation by degrading E-cadherin and thereby liberating β-catenin, priming renal tubules for regeneration. Taken together, these results suggest that induction of MMP-7 is protective in AKI by degrading FasL and mobilizing β-catenin, thereby priming kidney tubules for survival and regeneration.

The influence of melatonin on apoptosis of human neutrophils

Aim: Melatonin (Mel) besides its main role in circadian and seasonal rhythm coordination, plays a role in immunoregulation and inflammatory responses. The melatonin’s ability to modulate apoptosis is one of its important roles related to its effect on immune system but the exact effect of its action and the mechanisms of apoptosis control by melatonin remain still unclear. The goal of our study was to examine the involvement of melatonin in the apoptosis of human neutrophils in vitro and possible mechanisms of this action. Material/Methods: We measured the effect of melatonin on the spontaneous and TNF-α-induced apoptosis of human neutrophils using propidium iodide and Annexin-V and on caspase-3 activation, apoptosis-related surface antigen expressions, intracellular reactive oxygen species (ROS) generation and cytochrome c release using flow cytometry and commercial reagents. Results: Melatonin does not affect spontaneous apoptosis of human neutrophils and mitochondrial cytochrome c release but protects the cells from the significant rise of TNF-α-induced apoptosis and cytochrome c release. Intracellular ROS generation in PMA-stimulated neutrophils did not change after the influence of melatonin but the significant drop of ROS generation in neutrophils stimulated with TNF- α was upregulated to the control level after preincubation of the neutrophils with melatonin. Melatonin did not change significantly Fas, Fas-L and active caspase-3 expressions in neutrophils. Conclusions: Melatonin does not affect the spontaneous apoptosis, however, inhibits TNF-α-induced apoptosis of human neutrophils. Our findings suggest that the intrinsic pathway of the process is a result of the melatonin induced mitochondrial alterations.

Survivin induces defects in apoptosis in eosinophils in intestine with food allergy.

Survivin is an anti-apoptosis protein that may be associated with the development of eosinophilia; the latter is associated with the pathogenesis of many immune disorders. Here we report that less apoptotic eosinophils (Eos) were induced in those isolated from mice suffering from food allergy (FA) than those from naive mice after treating with cisplatin in vitro. Exposure to cisplatin induced more Fas ligand (FasL) expression in Eos isolated from naive mice than in those of FA mouse. Survivin was detected in the intestinal tissue extracts in much higher amounts in the FA group than in the naive group. Immunohistochemistry showed that epithelial cells were the major source of survivin in the intestine. Exposure to IL-4 or IL-13 up-regulated the expression of survivin in intestinal epithelial cells. Survivin interfered with the expression of FasL in Eos. Inhibition of survivin attenuated the eosinophilia-related inflammation in the intestine. In conclusion, intestinal epithelial cell-produced survivin induced defects in apoptosis in Eos to contribute to eosinophilia in the intestine. Inhibition of survivin can suppress the eosinophilia-related intestinal inflammation. The data suggest that survivin may be a novel target for the treatment of FA.

Cyclooxygenase-2 Inhibition Potentiates the Efficacy of Vascular Endothelial Growth Factor Blockade and Promotes an Immune Stimulatory Microenvironment in Preclinical Models of Pancreatic Cancer.

Resistance to standard therapy remains a major challenge in the treatment of pancreatic ductal adenocarcinoma (PDA). Although anti-VEGF therapy delays PDA progression, therapy-induced hypoxia results in a less differentiated mesenchymal-like tumor cell phenotype, which reinforces the need for effective companion therapies. COX-2 inhibition has been shown to promote tumor cell differentiation and improve standard therapy response in PDA. Here, we evaluate the efficacy of COX-2 inhibition and VEGF blockade in preclinical models of PDA. In vivo, the combination therapy was more effective in limiting tumor growth and metastasis than single-agent therapy. Combination therapy also reversed anti-VEGF-induced epithelial-mesenchymal transition and collagen deposition and altered the immune landscape by increasing tumor-associated CD8+ T cells while reducing FoxP3+ T cells and FasL expression on the tumor endothelium. IMPLICATIONS: Together, these findings demonstrate that COX-2 inhibition enhances the efficacy of anti-VEGF therapy by reducing hypoxia-induced epithelial plasticity and promoting an immune landscape that might facilitate immune activation.Visual Overview: http://mcr.aacrjournals.org/content/molcanres/17/2/348/F1.large.jpg.

Interleukin-5 induces apoptotic defects in CD4+ T cells of patients with allergic rhinitis.

T helper (Th)2 polarization plays an important role in the pathogenesis of allergic diseases; the underlying mechanism remains to be further investigated. B cell lymphoma protein-2 like protein-12 (Bcl2L12) has the anti-apoptotic function. This study aims to elucidate the contribution of Bcl2L12 to Th2 polarization in patients with allergic rhinitis (AR). In this study, human CD4+ T cells were isolated from blood samples collected from AR patients and healthy control (HC) subjects. The immune response profiles of CD4+ T cells were analyzed by immunologic approaches. The results showed that AR CD4+ T cells (CD4+ T cells collected from AR patients) showed defects of apoptosis. The expression of FasL in AR CD4+ T cells was lower than that of HC CD4+ T cells. Serum IL-5 levels were negatively correlated with the expression of FasL in AR CD4+ T cells. Exposure of CD4+ T cells to IL-5 in the culture suppressed the expression of FasL and increased the expression of Bcl2L12. IL-5 increased the levels of Bcl2L12 in CD4+ T cells, the latter bound to the FasL promoter to prevent FasL gene transcription. Inhibition of Bcl2L12 restored the apoptosis machinery in AR CD4+ T cells. In conclusion, overexpression of Bcl2L12 in CD4+ T cells compromises the apoptosis machinery; the latter can be restored by inhibition of Bcl2L12. BcL2L12 in CD4+ T cells may be a novel target for the treatment of AR and other allergic disorders.

Effect of erythropoietin on Fas/FasL expression in brain tissues of neonatal rats with hypoxic-ischemic brain damage.

Hypoxic-ischemic brain damage (HIBD) occurs due to intrauterine hypoxia ischemia influencing the energy supply for fetal brain cells, which affects the metabolism of the brain to make the brain suffer a severe damage. Erythropoietin (EPO), which regulates hemacytopoiesis, is a kind of cytokine. EPO is sensitive to hypoxia ischemia. In this study, we aimed to investigate the effect of EPO on the expression of Fas/FasL in brain tissues of neonatal rats with HIBD. Neonatal rats were assigned randomly to sham, HIBD, and EPO groups. Five time points for observation were 6, 12, 24, 48, and 72 h after the HIBD rat model had been established, respectively. In the HIBD group, Fas/FasL expression began to rise at 6 h, reached the peak at 12–24 h, and dropped from 24 h. In the EPO group, the expression of Fas/FasL was lower than those in HIBD group at 12, 24, and 48 h (P<0.05). Our findings suggest that EPO may reduce cell apoptosis after hypoxic-ischemic damage through reduction of the expression of Fas and FasL, and that optimal therapeutic time window is 6–24 h after HIBD.

Titanium Surface Properties Influence the Biological Activity and FasL Expression of Craniofacial Stromal Cells.

Mesenchymal stromal cells (MSCs) can be easily isolated form craniofacial bones during routine dentistry procedures. Due to their embryological origin from neural crest, they represent a suitable cell population to study cell-biomaterial interaction in the craniofacial field, including osteoinductive/osteointegrative processes. The biological and immunomodulatory properties of MSCs may be influenced by chemistry and topography of implant surfaces. We investigated if and how three different titanium surfaces, machined (MCH), sandblasted with resorbable blasting medium (RBM), and Ca++-nanostructured (NCA), may affect biological activity, osseointegration, and immunomodulatory properties of craniofacial MSCs. Cell proliferation, morphology, osteogenic markers, and FasL were evaluated on MSCs isolated from the mandibular bone after seeding on these three different surfaces. No statistically significant differences in cell proliferation were observed whereas different morphologies and growth patterns were detected for each type of surface. No difference in the expression of osteogenic markers was revealed. Interestingly, FasL expression, involved in the immunomodulatory activity of stem cells, was influenced by surface properties. Particularly, immunofluorescence analysis indicated that FasL expression increased on MCH surface compared to the others confirming the suggested role of FasL in promoting osteogenic differentiation. Titanium surface treatments and topography might reflect different biological behaviours of craniofacial MSCs and influence their osseointegration/immunomodulation properties.

Chlorogenic acid potentiates antitumor effect of doxorubicin through upregulation of death receptors in solid Ehrlich carcinoma model in mice

ABSTRACTThis study aimed to evaluate the antitumor effect of chlorogenic acid (CGA) alone and in combination with doxorubicin (DOX) in solid Ehrlich carcinoma (SEC) model in mice. In addition, we investigated the possible cardioprotective effect of CGA against DOX-induced cardiotoxicity. CGA, DOX and their combination were given for 21 days in mice bearing SEC. Tumor volume and weight were measured, and serum CRP was determined by latex immunoassay. Moreover, mRNA expressions of TRAIL, TRAILR2, FasL, Fas, caspase-3 and Bcl-2 were measured using RT-PCR. Histopathological examination of tumor and cardiac tissues was carried out using hematoxylin and eosin. Active caspase-3 was detected by immunohistochemistry. CGA and/or DOX treatment showed a remarkable decrease in solid tumor volume and weight. CGA and/or DOX groups revealed upregulation in gene expressions of TRAIL/TRAILR2, FasL/Fas and caspase-3 genes and downregulation of Bcl-2 gene expression, as well as a marked increase in active caspase-3 expression. Moreover, CGA and DOX combination significantly decreased MDA and increased GSH levels in tumor tissues and also reduced the level of serum CRP, CK-MB and LDH as compared to DOX group. In conclusion, CGA has the ability not only to enhance the anti-tumor activity of DOX but also protects against DOX-induced cardiotoxicity.

Fas, FasL and Foxp3 gene expression in post-liver transplant autoimmune hepatitis patients with and without acute rejection.

Aim of the studyIn this study we investigated Fas, FasL and Foxp3 expression in relation to liver graft rejection and its severity in autoimmune hepatitis (AIH) patients.Material and methodsTwenty-three AIH patients including five post-transplant patients with acute rejection (AR) and 18 patients without AR (non-AR) were studied for Fas, FasL and Foxp3 gene expression in peripheral blood mononuclear cells on days 1, 3 and 7 after transplantation by real-time PCR. The relationships between gene expression and clinical features were determined.ResultsReal-time PCR showed various Fas gene expression levels with no significant difference between the days in AR patients (p = 0.52). In non-AR patients, Fas level increased from 0.98 ±0.24 fold on the first day to 1.89 ±0.42 fold on day 3 after transplantation (p < 0.01). In this group of patients, we also found a significant increase in FasL expression on day 7 (29.91 ±6.89 fold) compared to day 1 (13.50 ±7.44 fold, p < 0.05). Foxp3 gene expression in both groups showed decreased levels during the first week after transplantation. The decreased Foxp3 expression in AR patients was correlated with rejection activity index (r = 0.86, p < 0.0001).ConclusionsIncreased Fas and FasL gene expression levels in non-AR patients and decreased Foxp3 gene expression in both groups suggested the important role of these molecules in the alloreactive response after liver transplantation in AIH patients. Foxp3 expression might be useful for monitoring rejection severity.

Proapoptotic activities of Oroxylum indicum leave extract in HeLa cells

Objective: To examine the proapoptotic properties of Oroxylum indicum methanol extract on cervical cancer cells. Methods: Methylene blue assay was used to determine the IC50 value of the extract. Western blotting assays were done to analyze the expression of HPV oncoproteins (HPV18 E6 and E7) and apoptotic molecules (caspase-3 and caspase-8). Reverse transcriptase PCR assays were performed to determine genetic alteration of tumor suppressors p53 and pRb and apoptosis markers Fas and FasL. Enzyme-linked immunosorbent assay (ELISA) was done to determine the expression of cytokine levels (IL-6 and IL-12). Results: The determination of IC50 value indicated a higher anti-proliferative activity of the extract compared to cisplatin. After 24 hours of treatment, Western blot analysis showed that treated HeLa cells exhibited a significant down-regulation of HPV18 oncoproteins E6 and E7, and a significant induction of caspase-8 and caspase-3 activation level. Meanwhile, the mRNA expressions of p53, pRb, Fas and FasL were significantly upregulated in treated cells. Moreover, ELISA showed an increased IL-12 and decreased IL-6 production after Oroxylum indicum treatment. Conclusions: The methanol extract of Oroxylum indicum has an anti-proliferative activity and proapoptotic potential. It induces localized-immunity improvements by altering cytokine production in HPV-positive cervical cancer cells.

Regulating Bcl2L12 expression in mast cells inhibits food allergy.

Rationale: Mast cells play a crucial role in allergic diseases. Yet, the regulation of mast cell bioactivities is not fully understood. This study aims to elucidate the role of B cell lymphoma 2 like protein 12 (Bcl2L12), one of the anti-apoptosis proteins, in regulating mast cell apoptosis.Methods: A food allergy (FA) mouse model was developed to establish mast cell over population in the intestinal tissue. Either compound 48/80 (C48/80) or specific antigens were used to activate mast cells in the intestinal mucosa.Results: After treating with C48/80, apoptosis was induced in mast cells of the intestine of naive control mice, but not in FA mice. The expression of Fas ligand (FasL) was lower in the mast cells of FA mice. Interleukin (IL)-5 was responsible for the suppression of FasL by upregulating the expression of Bcl2L12 in mast cells. Bcl2L12 prevented c-Myc, the major transcription factor of FasL, from binding the FasL promoter to inhibit the expression of FasL in mast cells. Inhibition of Bcl2L12 restored the apoptosis machinery of mast cells in the FA mouse intestine.Conclusions: The apoptosis machinery in mast cells is impaired in an allergic environment. Inhibition of Bcl2L12 restores the apoptosis machinery in mast cells in the FA mouse intestine.

Quercetin Enhances Ligand-induced Apoptosis in Senescent Idiopathic Pulmonary Fibrosis Fibroblasts and Reduces Lung Fibrosis In Vivo

Although cellular senescence may be a protective mechanism in modulating proliferative capacity, fibroblast senescence is now recognized as a key pathogenic mechanism in idiopathic pulmonary fibrosis (IPF). In aged mice, abundance and persistence of apoptosis-resistant senescent fibroblasts play a central role in nonresolving lung fibrosis after bleomycin challenge. Therefore, we investigated whether quercetin can restore the susceptibility of senescent IPF fibroblasts to proapoptotic stimuli and mitigate bleomycin-induced pulmonary fibrosis in aged mice. Unlike senescent normal lung fibroblasts, IPF lung fibroblasts from patients with stable and rapidly progressing disease were highly resistant to Fas ligand (FasL)-induced and TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis. Senescent IPF fibroblasts exhibited decreased expression of FasL and TRAIL receptors and caveolin-1, as well as increased AKT activation, compared with senescent normal lung fibroblasts. Although quercetin alone was not proapoptotic, it abolished the resistance to FasL- or TRAIL-induced apoptosis in IPF fibroblasts. Mechanistically, quercetin upregulated FasL receptor and caveolin-1 expression and modulated AKT activation. In vivo quercetin reversed bleomycin-induced pulmonary fibrosis and attenuated lethality, weight loss, and the expression of pulmonary senescence markers p21 and p19-ARF and senescence-associated secretory phenotype in aged mice. Collectively, these data indicate that quercetin reverses the resistance to death ligand-induced apoptosis by promoting FasL receptor and caveolin-1 expression and inhibiting AKT activation, thus mitigating the progression of established pulmonary fibrosis in aged mice. Therefore, quercetin may be a viable therapeutic option for IPF and other age-related diseases that progress with the accumulation of senescent fibroblasts.

Anti-tumour Effect and Pharmacokinetics of an Active Ingredient Isolated from Inonotus hispidus.

Inonotus hispidus is an anti-tumour drug used in folk medicine. (4S,5S)-4-Hydroxy-3,5-dimethoxycyclohex-2-enone (HDE) is a compound isolated from Inonotus hispidus for the first time. However, the mechanisms underlying its therapeutic effects have not been elucidated. In this study, the in vitro screening, in vivo anti-tumour effects, mechanism of action, pharmacokinetics, and tissue distribution of HDE were investigated. HDE could inhibit the proliferation of HepG2 cells. Additionally, its half-maximal inhibitory concentration was 7.9 µg/mL. Increasing HDE concentrations significantly increased apoptosis rate in a dose-dependent manner. Furthermore, HDE was rapidly absorbed into mouse plasma, reaching a maximum concentration at 30 min. The area under the plasma HDE concentration-time curves for the studied organs were as follows: spleen > liver > lung > kidney > muscle > thymus > heart > brain. HDE also inhibited tumour growth up to 69%. The weights of organs harvested from HDE-treated mice were not significantly different from those harvested from control mice. Furthermore, HDE upregulated Fas expression and downregulated FasL expression in HepG2 cells. HDE significantly increased caspase-3 and caspase-8 activity. The anti-tumour effect of HDE might be realized by activating the Fas-mediated apoptotic pathway. We also found that HDE undergoes enterohepatic circulation or is quickly absorbed by the body, and the drug is released back into systemic circulation. In conclusion, HDE significantly inhibited H22 hepatocarcinoma cells (H22)tumour growth in mice without damaging organs; therefore, it may be suitable for treating liver cancer.

L-arginine inhibited apoptosis of fish leukocytes via regulation of NF-κB-mediated inflammation, NO synthesis, and anti-oxidant capacity

The increased apoptosis plays an important role in bacterial invasion. In addition, LPS can induce inflammation and apoptosis of leukocytes via the production of reactive oxygen and nitrogen species. In the present study, we investigated the potential protective role of l-arginine (L-Arg) against the apoptosis of fish leukocytes in vitro. The results of Annexin V-FITC/PI staining and TUNEL assay indicated that L-Arg significantly alleviated the apoptosis of fish leukocytes induced by LPS at 24 h and 72 h post incubation (hpi). High caspase-3 activities induced by LPS at 72 hpi were significantly inhibited by L-Arg. Moreover, L-Arg supplementation also significantly decreased the mRNA expression levels of caspases at most time points, which contributed to the anti-apoptotic roles of L-Arg. Further analysis showed that L-Arg significantly inhibited the expression of several pro-inflammatory cytokines including IL-8 and TNF-α, partially via the down-regulation of the genes involved in NF-κB/MyD88 including NF-κB, IKKα and IKKγ. The down-regulation of these pro-inflammatory cytokines by L-Arg supplementation led to the further decrease in the expression of death receptor FasL, contributing to the anti-apoptotic effect of L-Arg. In addition, L-Arg supplementation increased both iNOS mRNA expression and NO production. The mRNA expressions of several anti-oxidant enzymes including SOD, CAT and GSHPx were also significantly increased after L-Arg supplementation, which accelerated the clearance of reactive oxygen species. In all, L-Arg inhibited apoptosis of fish leukocytes both via the increased NO production and antioxidant capacity and via the inhibition of inflammation mediated by NF-κB/MyD88 pathway.

B-cell-specific-peroxisome proliferator-activated receptor γ deficiency augments contact hypersensitivity with impaired regulatory B cells.

Nuclear receptor peroxisome proliferator-activated receptor γ (PPAR-γ) activation can prevent immunoinflammatory disorders and diabetes. B cells play protective roles during inflammation as well. However, the roles of endogenous PPAR-γ in the regulatory properties of B cells to relieve inflammation remain unknown. Here, we developed B-cell-specific PPAR-γ knockout (B-PPAR-γ-/- ) mice and found that the conditional deletion of PPAR-γ in B cells resulted in exaggerated contact hypersensitivity (CHS). Meanwhile, interferon-γ (IFN-γ) of CD4+ CD8+ T cells was up-regulated in B-PPAR-γ-/- mice in CHS. This showed that the regulatory function of B cells in B-PPAR-γ-/- mice declined in vivo. Whereas splenic CD5+ CD1dhi regulatory B-cell numbers and peripheral regulatory T-cell numbers were not changed in naive B-PPAR-γ-/- mice. Loss of PPAR-γ in B cells also did not affect either CD86 or FasL expression in splenic CD5+ CD1dhi regulatory B cells after activation. Notably, interleukin-10 (IL-10) production in CD5+ CD1dhi regulatory B cells reduced in B-PPAR-γ-deficient mice. In addition, functional IL-10-producing CD5+ CD1dhi regulatory B cells decreased in B-PPAR-γ-/- mice in the CHS model. These findings were in accordance with augmented CHS. The current work indicated the involvement of endogenous PPAR-γ in the regulatory function of B cells by disturbing the expansion of IL-10-positive regulatory B cells.

Autoimmune response in lung cancer patients with neurological paraneoplastic syndromes.

The aim of this study was to evaluate granzyme B, perforin and FasL expression in peripheral blood mononuclear cells (PBMCs) in lung cancer patients and in paraneoplastic neurological syndromes (PNS). Cellular immune response is activated as part of anti-tumour reaction of the malignancy-bearing host. Paraneoplastic neurological syndromes (PNS) are defined as indirect effects of cancer on the nervous system and are considered immune-mediated. Such stimulation of the immune system may limit the aggressiveness of cancer and the development of metastasis, and thereby improve survival. Granzyme B and perforin pathway, and Fas ligand (FasL) - Fas receptor interaction play an important role in cytotoxic response. Fifty-two patients were included in the study: 28 subjects with PNS and 24 subjects with lung cancer. PNS cases were diagnosed according to the Graus criteria. The presence of onconeural antibodies (anti-Hu/anti-Ri/anti-Yo/anti-Ma/Ta/anti-CV2/anti-amphiphysin/anti-myelin/anti-neuroendothelium/anti-MAG/anti-GAD) was detected with indirect immunofluorescence and confirmed with Line Blotting. The expression of granzyme B, perforin and FasL was detected in PBMCs with ELISA. PPBMC-FasL expression was increased in lung cancer compared to other patient groups. The granzyme to FasL ratio was significantly higher in lung cancer patients with peripheral than with central PNS involvement. In a multiple regression model, sex was an independent factor influencing PBMC expression of granzyme and perforin. FasL expression in PBMCs is up-regulated in lung cancer patients. The interplay between granzyme B and FasL may be involved in the development of PNS at the level of the peripheral and the central nervous systems in different manners. Gender is associated with PBMC expression of granzyme B and perforin in lung cancer patients. The novel findings that we report broaden the current knowledge on PNS pathomechanism, with aspects that have not been previously explored. Our findings provide a rationale for further exploration of the granzyme B/FasL pathway with regards to its potential diagnostic value. However, our study is preliminary and needs further research, especially in the context of the prognostic value of the proposed markers.