Cystic fibrosis epithelial cells are primed for apoptosis as a result of increased Fas (CD95)

Background

Previous work suggests that apoptosis is dysfunctional in cystic fibrosis (CF) airways with conflicting results. We evaluated the relationship between dysfunctional cystic fibrosis transmembrane conductance regulator (CFTR) and apoptosis in CF airway epithelial cells.

Proapoptotic Fas ligand is expressed by normal kidney tubular epithelium and injured glomeruli

Fas ligand (FasL) is a cell membrane cytokine that can promote apoptosis through activation of Fas receptors. Fas receptor activation induces glomerular cell apoptosis in vivo and participates in tubular cell death during acute renal failure. However, there is little information on the expression of FasL in the kidney. This study reports that FasL mRNA and protein are present in normal mouse and rat kidney. In situ hybridization and immunohistochemistry showed that proximal tubular epithelium is the main site of FasL expression in the normal kidney. In addition, increased total kidney FasL mRNA and de novo FasL protein expression by glomerular cells were observed in two different models of glomerular injury : rat immune-complex proliferative glumerulonephritis and murine lupus nephritis. Both full-length and soluble FasL were increased in the kidneys of the mice with nephritis. Cultured murine proximal tubular epithelial MCT cells and primary cultures of murine tubular epithelial cells expressed FasL mRNA and protein. Tubular epithelium-derived FasL induced apoptosis in Fassensitive lymphoid cell lines but not in Fas-resistant lymphoid cell lines. By contrast, MCT cells grown in the presence of the survival factors of serum were resistant to FasL, and only became partially sensitive to apoptosis induced by high concentrations (100 ng/ml) of FasL upon serum deprivation. However, MCT cells stimulated with inflammatory mediators (tumor necrosis factor-alpha, interferon-gamma, and lipopolysaccharide) increased cell surface Fas expression and were sensitized to apoptosis induced by FasL (FasL 55 +/- 5% versus control 8.3 +/- 4.1% apoptotic cells at 24 h, P < 0.05). Cytokine-primed primary cultures of tubular epithelial cells also acquired sensitivity to FasL-induced apoptosis. These results suggest that FasL expression by intrinsic renal cells may play a role in cell homeostasis in the normal kidney and during renal injury.     

Fas and Fas-ligand expression in human pancreatic cancer

OBJECTIVE: To investigate Fas and FasL expression in pancreatic tissues and cultured pancreatic cancer cell lines, and to assess the ability of anti-Fas antibodies to induce apoptosis. SUMMARY BACKGROUND DATA: Activation of the Fas receptor by Fas-ligand (FasL) results in apoptosis, and dysregulation of this pathway may contribute to abnormal cell proliferation. METHODS: Northern blotting and immunohistochemistry were used to compare Fas and FasL expression in normal and cancerous tissues. DNA 3'-OH end labeling was used to detect apoptotic cells. The effects of Fas activation on cell growth and signaling pathways were investigated in culture. RESULTS: Pancreatic cancers exhibited increased Fas RNA levels, whereas FasL mRNA levels were similar in both groups. Despite the colocalization of Fas and FasL in the cancer cells, an apoptotic signal was present in approximately 10% of these cells in only 2 of 16 cancer samples. Fas and FasL were coexpressed in all four cell lines, whereas Fas-associated phosphatase 1 was below the level of detection in all cell lines. Only COLO-357 cells underwent apoptosis after Fas activation. Apoptosis was associated with enhanced activation of jun kinase (JNK) and p38 mitogen-activated protein kinase (MAPK). In the presence of actinomycin D, Fas antibody also induced apoptosis in the other three cell lines. CONCLUSIONS: These results suggest that pancreatic cancer cells are resistant to Fas-mediated apoptosis by mechanisms excluding receptor downregulation or Fas-associated phosphatase upregulation and raise the possibility that Fas-mediated apoptosis may be dependent on the activation of the JNK/p38 MAPK pathway in these cells.     

Fas配体在泌尿生殖肿瘤细胞系及肾癌组织中的表达

目的 明确Ｆａｓ配体在泌尿生殖肿瘤细胞系及肾癌组织中的表达情况。方法 采用免疫细胞化学和反转录ＰＣＲ（ＲＴ－ＰＣＲ）法检测膀胱癌（Ｔ２４、ＢＩＵ－８７、ＥＪ）、肾癌（ＧＲＣ－１、ＲＣＣ－９４９）、前列腺癌（ＰＣ－３Ｍ）及１０例肾癌组织上Ｆａｓ配体的表达。结果 免疫细胞化学方法检测细胞系中Ｆａｓ配体表达于ＢＩＵ－８７、ＲＣＣ－９４９和ＧＲＣ－１细胞,而以ＢＩＵ－８７和ＲＣＣ－９４９细胞系表达较强,在     

p53基因、 Fas/FasL在提高肝癌细胞化疗药物敏感性中的作用

目的：探讨野生型p53(wtp53)、Fas/FasL在提高肝癌细胞化疗药物敏感性中的作用及其机制。方法：用化疗药物争光霉素600mg/L分别处理人肝癌细胞株HepG2、Hep3B和PLC／PRF／5，观察争光霉素对肝癌细胞Fas/FasL表达的影响；预先将携带wtp53基因的重组腺病毒分别感染人肝癌细胞株24h，再用争光霉素进行诱导，观察感染前后肝癌细胞Fas/FasL的表达变化，并对经上述处理前后的肝癌细胞进行凋亡检测。结果：单纯争光霉素600mg/L诱导虽可提高肝癌细胞FasL的表达，但对其Fas的表达并无明显作用；感染wtp53基因后再应用争光霉素（600mg/L），则肝癌细胞Fas/FasL的表达水平不仅显著高于单纯争光霉素组，同时自身也发生了明显凋亡。结论：wtp53基因可能是通过上调肝癌细胞Fas/FasL的表达来降低其自身的凋亡阈值，进而提高肝癌细胞对化疗药物的敏感性，Fas/FasL在wtp53基因逆转肝癌细胞耐药性中具有一定的作用。     

In vitro 3D culture lung model from expanded primary cystic fibrosis human airway cells

BackgroundIn vitro cystic fibrosis (CF) models are crucial for understanding the mechanisms and consequences of the disease. They are also the gold standard for pre-clinical efficacy studies of current and novel CF drugs. However, few studies have investigated expansion and differentiation of primary CF human bronchial epithelial (CF-HBE) cells. Here we describe culture conditions to expand primary CF airway cells while preserving their ability to differentiate into 3D epithelial cultures expressing functional cystic fibrosis transmembrane conductance regulator (CFTR) ion channels that responds to CFTR modulators.MethodsPrimary CF airway cells were expanded using PneumaCult^TM-Ex Plus (StemCell Technologies) medium with no feeder cells or added Rho kinase (ROCK) inhibitor. Differentially passaged CF-HBE cells at the air-liquid interface (ALI) were characterized phenotypically and functionally in response to the CFTR corrector drug VX-661 (Tezacaftor).ResultsCF-HBE primary cells, expanded up to six passages (~25 population doublings), differentiated into 3D epithelial cultures as evidenced by trans-epithelial electrical resistance (TEER) of >400 Ohms∙cm² and presence of pseudostratified columnar ciliated epithelium with goblet cells. However, up to passage five cells from most donors showed increased CFTR-mediated short-circuit currents when treated with the corrector drug, VX-661. Ciliary beat frequency (CBF) also increased with the corrector VX-661.ConclusionsCF donor-derived airway cells can be expanded without the use of feeder cells or additional ROCK inhibitor, and still achieve optimal 3D epithelial cultures that respond to CFTR modulators. The study of rare CF mutations could benefit from cell expansion and could lead to the design of personalized medicine/treatments.     

Renal Tubular Epithelial Cell Self-Injury Through Fas/Fas Ligand Interaction Promotes Renal Allograft Injury

Tubular epithelial cells (TECs) coexpress Fas and Fas ligand (FasL), which could influence renal allograft injury. While TECs can resist apoptosis by Fas antibody, TEC apoptosis by contact with adjacent TECs has not been studied. Fas expression increased in TECs with cytokine treatment (IFN-gamma, TNF-alpha) while abundant FasL levels were not altered. Apoptosis (Annexin-V, DNA fragmentation) occurred in cytokine-treated TECs monolayers from C3H-HeJ mice by 24 h, but was absent in similarly treated TECs from Fas-deficient (lpr) or FasL-mutant (gld) mice, suggesting that 'self injury' occurred through Fas/FasL. Membrane labeling of TECs in cocultures confirmed that FasL-bearing TECs induced apoptosis when in contact with Fas-bearing TECs. Culturing TECs with allogeneic C57BL/6 (H-2b) splenocytes resulted in apoptosis and elimination of C3H-HeJ TECs by 48 h, with enhanced survival and reduced apoptosis using lpr or gld TECs. In a renal allograft model, survival of C57BL/6 recipients was greater (p < 0.05) and renal function improved (p < 0.001) using C3H-lpr or C3H-gld (H-2 k) donor kidneys compared with C3H-HeJ kidneys. These data demonstrate for the first time that cytokine-activated TECs can injure TECs through expression of functional FasL and Fas. We suggest that inhibition of TEC-TEC 'self injury' may be a novel strategy to augment renal allograft survival.     

狼疮肾炎患者外周血单核细胞表达有功能的Fas

目的 探讨狼疮肾炎（ＬＮ）患者单核细胞凋亡加速的机制。方法 对灯例ＬＮ患者进行观察及以 １５例正常人为对照。采用流式细胞仪检测单核细胞 ＦａＳ和 Ｆａｓ Ｌｉｇａｎｄ（ＦａｓＬ）的表达；单核细胞与重组人ＦａＳＬ共孵育，碘化丙啶染色、流式细胞仪检测单核细胞凋亡，四甲基偶氮唑蓝（ＭＴＴ）法观察单核细胞体外存活率。结果ＬＮ患者单核细胞Ｆａｓ的表达较正常人明显上调（Ｐ＜０．０５）；处于狼疮活动期的ＬＮ患者与狼疮静止期的ＬＮ患者之间Ｆａｓ的表达差异无显著性意义（Ｐ＞０．０５）。正常人和ＬＮ患者的单核细胞表面均未检测出ＦａｓＬ的表达。单核细胞与重组人ＦａｓＬ在体外共同培养２ｈ后，ＬＮ者单核细胞的凋亡较正常人明显增加（Ｐ＜０．０５），单核细胞与重组人 ＦａｓＬ在体外共同培养６ｈ后，ＬＮ患者单核细胞的存活率较正常人明显低下（Ｐ＜０．０５）。结论 ＬＮ患者单核细胞表面功能性Ｆａｓ表达上调是ＬＮ患者单核细胞凋亡加速的可能机制。     

The Fas ligand/Fas system in renal injury.

The FasL-Fas system regulates renal cell apoptosis, as well as the immune and inflammatory responses. Evidence that FasL and Fas participate in renal injury may be summarized along modified Koch's postulates (Table 1): (i) FasL is expressed by renal cells and during renal injury, (ii) activation of the Fas receptor promotes apoptosis of cultured renal cells, (iii) Fas agonists induce glomerular injury but they may also decrease renal injury by limiting injurious immunological responses, (iv) mice with disrupted FasL/Fas systems are protected from tubular cell injury during ischaemia reperfusion, although they develop autoimmune glomerulonephritis if other genetic predisposing factors are present. FasL/Fas must be considered a new target for therapeutic intervention in renal injury. Therapeutic modulation of Fas should aim not only at protecting intrinsic glomerular or tubular epithelial cells from death, but also at modulating the immune, inflammatory, and fibrogenic responses. Possible therapeutic interventions include Fas agonists, soluble Fas receptors, or other antagonists, and targetting of Fas to undesired cells, such as fibroblasts, in order to decrease their numbers in a physiological manner through apoptosis. Any therapeutic attempt should carefully take into account the possible effects of interference with Fas in other 1833 cell systems. Given the complexities of the FasL/Fas system, further studies are warranted.     

A non-cleavable mutant of Fas ligand does not prevent neutrophilic destruction of islet transplants

BACKGROUND: Fas ligand (FasL) mediates apoptosis of susceptible Fas-expressing lymphocytes, and may contribute to the maintenance of peripheral tolerance. In transplantation models, however, artificial expression of FasL on cellular as well as islet transplants results in accelerated rejection by neutrophils. The mechanism of the neutrophilic response to FasL expression is unknown. FasL, like other members of the tumor necrosis factor family, is cleaved to a soluble form by metalloproteases. We tested the hypothesis that soluble FasL (sFasL) was responsible for neutrophil migration by creating a non-cleavable mutant of FasL. METHODS: Three mutants of FasL with serial deletions in the putative proteolytic cleavage site of human FasL were made using inverse polymerase chain reaction. The relative fractions of sFasL and membrane-bound FasL were assessed by Western blot and immunoprecipitation, as well as by cytotoxicity assay using Fas-expressing target cells. The fully non-cleavable mutant was transduced into murine islets as well as myoblasts and tumor cell lines, and tested in a murine transplantation model. RESULTS: Serial deletions in the putative metalloprotease site of FasL resulted in a fully non-cleavable mutant of FasL (ncFasL). Expression of ncFasL in tumor lines induced higher levels of apoptosis in Fas bearing targets than wild-type FasL. Transplantation of ncFasL-expressing islets under the kidney capsule of allogenic mice resulted in accelerated rejection identical to that seen with wild-type Fas ligand-expressing islets. Myoblasts and tumor cell lines expressing ncFasL also induced neutrophil infiltration. CONCLUSIONS: Membrane-bound Fas ligand is fully capable of inducing a neutrophilic response to transplants, suggesting an activation by Fas ligand of neutrophil chemotactic factors.     

Transitional cell carcinoma expresses high levels of Fas ligand in vivo

OBJECTIVE: To characterize the Fas-Fas ligand system, a main apoptotic pathway, in transitional cell carcinoma (TCC) of the urinary bladder, by analysing the expression of Fas and Fas ligand (FasL) in TCC samples. MATERIALS AND METHODS: Archival paraffin-embedded tissues from 37 patients with TCC were analysed by immunohistochemistry to determine Fas and FasL expression. RESULTS: Fas and FasL were detected on the cell surface and cytoplasm of respectively 34 (92%) and all cases analysed. The expression of Fas and FasL did not differ with the cytological grade of TCC. CONCLUSION: The high expression of FasL in TCC, reported for the first time in the present study, suggests that FasL may contribute to the immune escape of TCC through killing Fas-bearing lymphocytes. Co-expression of Fas with FasL also suggests that TCC may have pathways resistant to Fas-mediated autocrine cell suicide.     

Expression of Fas and Fas ligand in human testicular germ cell tumours

In the present study, we analysed the expression of Fas ligand (FasL) and its cognate receptor Fas in 14 seminomatous testicular germ cell tumours (TGCT) and six normal testicular tissues obtained following orchiectomy. Tissue samples have been processed to prepare either total RNA or protein extracts or fixed and embedded in paraffin for immunohistochemistry (IHC) experiments. Quantitative RT-PCR experiments demonstrated in TGCT a significant ( p  < 0.01) increase of the FasL mRNA expression of 21.1 ± 5.4 fold, with respect to normal tissues. On the contrary, in the same cancer tissues, the levels of Fas mRNA were significantly ( p  < 0.01) reduced to 0.27 ± 0.06 fold. These observations were confirmed in western blot experiments showing a significant increase of FasL and a concomitant decrease of Fas proteins in testicular cancer tissues, with respect to normal testis. Moreover, IHC experiments showed a strong FasL immuno-reactivity in six out of eight TGCT samples analysed, while Fas immuno-positivity was found in cancer cells of only two TGCT tissues. In addition, in all tumour samples, infiltrating lymphocytes were Fas positive. However, no correlation could be observed between Fas or FasL mRNA variations and clinical parameters such as patient's age, TNM stage or tumour size. We also compared the serum levels of soluble FasL (sFasL) of 15 patients affected by seminomatous TGCT, of four patients with non-seminomatous TGCT and six age-matched healthy males. No significant differences in sFasL serum level could be identified. In conclusion, our data demonstrated that the majority of seminomas are characterized by an increased expression of FasL and a concomitant reduction of Fas, with respect to human normal testis, and that sFasL serum level is not a tumour marker for patients affected by TGCT.     

Fas和FasL蛋白在肾癌组织中的表达及意义

目的　探讨凋亡相关基因产物Fas和FasL蛋白在肾癌发生中的作用以及与转移、预后的关系。方法　采用免疫组织化学方法对46例肾癌组织和15例正常肾组织Fas和FasL蛋白的表达进行检测。结果　肾癌组织Fas表达率为18.14%,低于正常肾组织（46.15%,P<0.05）,随肾癌分级的增加,表达强度下降。肾癌组织FasL蛋白表达率为70.26%,高于正常肾组织（10.32%,P<0.05）,随肾癌分级的增加,表达强度增高。正常肾组织Fas与FasL的表达有相关性（r=0.689,P<0.05）,肾癌组织无相关性（r=0.143,P>0.05）,有淋巴结转移组FasL(89.42%)与无淋巴结转移组(60.39%)比较,差别有显著性意义(P<0.01)。生存率>5年组Fas(25.39%)和FasL(61.26%)与生存率<5年组Fas(15.24%)和FasL(85.35%)的差别均有显著性意义(P均<0.05)。结论　Fas和FasL蛋白相互作用失衡在肾癌的发生、发展中起重要作用,表达情况与肾癌病理分级及转移、预后有一定关系。     

Fas ligand expression in Hodgkin lymphoma

Because previous investigations suggested involvement of the Fas ligand (FasL) in the selection process in the follicular dendritic cell (FDC)-associated cell cluster of the germinal center, we investigated the expression of FasL in Hodgkin lymphoma (HL) on protein and RNA level, while considering the Epstein-Barr virus status of the Hodgkin and Reed-Sternberg (HRS) cells. Tumor tissue from 47 patients with classic HL (32 nodular sclerosis [NS], 11 mixed cellularity [MC], and 4 lymphocyte-rich [LR]) was analyzed by immunohistochemistry for FasL, Fas, CD21, and CD23 and by Western blotting for FasL. FasL mRNA was detected by an exon 4-specific oligonucleotide and Epstein-Barr virus infection by in situ hybridization for Epstein-Barr virus early RNAs (EBER). Western blotting showed soluble and membrane-bound forms of FasL. Immunohistochemistry showed FasL expression in virtually all HRS of 94% of NS cases and 82% of MC cases. FasL expression did not correlate with the Epstein-Barr virus status of the HRS. Low FasL protein expression was found in some HRS of LR cases. FasL mRNA was detected in 39% of NS, 46% of MC, and 33% of LR cases. Seventy percent to 90% of the HRS cells expressed Fas. CD21 immunohistochemistry showed disrupted FDC networks in the tumor tissue with reduced and virtually absent expression of CD23 and FasL. These observations suggest that FasL expression in HRS cells and the absence of FasL in the FDC cluster represent a disturbed microenvironment that may be involved in the pathogenesis of HL.     

Molecular characterization of gene regulatory networks in primary human tracheal and bronchial epithelial cells

Background

Robust methods to culture primary airway epithelial cells were developed several decades ago and these cells provide the model of choice to investigate many diseases of the human lung. However, the molecular signature of cells from different regions of the airway epithelium has not been well characterized.

Loss of ciliated cells and altered airway epithelial integrity in cystic fibrosis

BackgroundIn cystic fibrosis, the respiratory epithelium is the target tissue of both the genetic abnormality of the disease and of external aggressions, notably by pathogens (Pseudomonas aeruginosa). A detailed characterisation of the cystic fibrosis bronchial epithelium is however lacking, as most previous studies focused on the nasal epithelium or on cell lines. This study aimed to characterise the abnormal phenotype and epithelial-to-mesenchymal transition in cystic fibrosis bronchial epithelium and to evaluate in cell cultures whether abnormalities persist ex vivo.MethodsExplant lung tissues (n = 44) were assessed for bronchial epithelial cell phenotyping by immunostaining. Human bronchial epithelial cells were derived from basal cells isolated from cystic fibrosis patients or control donors and cultured in air-liquid interface for 2, 4 or 6 weeks.ResultsEnhanced mucin 5AC and decreased β-tubulin expression were observed in cystic fibrosis airways reflecting a decreased ciliated/goblet cell ratio, associated with increased number of vimentin-positive cells, indicating epithelial-to-mesenchymal transition process. These features were recapitulated in vitro, in cystic fibrosis-derived reconstituted epithelium. However, they were not induced by CFTR inhibition or Pseudomonas infection, and most abnormalities tended to disappear in long-term culture (6 weeks) except for increased fibronectin release, an epithelial-to-mesenchymal transition marker.ConclusionsThis study provides new insights into airway epithelial changes in cystic fibrosis, which are imprinted through an acquired mechanism that we could not relate to CFTR function.     

FasL、抗DR5单克隆抗体对结肠癌细胞株HT29的杀伤作用及其机制

目的 探讨FasL、抗DR5单克隆抗体(Anti-DR5 mAb)对结肠癌细胞株HT29的杀伤作用及机制.方法 采用逆转录-聚合酶链反应(RT-PCR)、噻唑蓝(MTT)比色法、DNA倍体分析,Western blot等.结果 HT29细胞表面Fas mRNA的表达低于DIL5 mRNA的表达.50 mg/L FasL和Anti-DR5 mAb对HT29细胞的杀伤率分别为(25.49±0.90)%和(48.90±3.15)%,这种作用呈剂量依赖性.流式细胞术分析细胞周期和凋亡实验表明FasL和Anti-DR5 mAb能够抑制HT29细胞的生长,并且诱导它的凋亡.25 mg/L FasL和Anti-DR5 mAb对HT29细胞的凋亡指数分别为(13.8±1.5)%和(22.6±1.1)%.FasL和Anti-DR5 mAb作用HT29细胞后,Caspase-3蛋白表达上升,bcl-2蛋白表达水平下降.结论 FasL、Anti-DR5 mAb能不同程度的诱导结肠癌细胞株HT29凋亡,其机制与其受体和Caspase-3、bcl-2的表达有关.     

Expression of apoptosis-related genes after fetal tracheal occlusion in rabbits

Background/purpose

Late-gestation lung remodeling is associated with alveolar type II cell apoptosis early in the saccular stage (day 28 in fetal rabbits). Intrauterine tracheal occlusion (TO), a potent stimulus of fetal lung growth and maturation, significantly increases type II cell apoptosis. The aim of this study was to determine the effect of fetal TO on the spatiotemporal expression of key apoptosis-related signaling molecules.

Methods

Tracheal occlusion of fetal rabbits was performed at gestational day 25 (term, 31 days), and apoptotic gene expression was studied between days 26 and 28.

Results

At days 26 and 27, the protein levels of Fas and Fas-ligand (FasL) in lung lysates were similar in TO fetuses and sham-operated controls. At day 28, however, synchronous with the onset of TO-induced pulmonary distension and type II cell apoptosis, the FasL protein content was 8-fold higher in TO lungs compared with controls (P < .01), whereas Fas levels were comparable. In contrast, Bax and Bcl-2 protein levels were similar in TO and control fetuses at all time-points. TO significantly increased the cellular concentration of immunoreactive FasL in type II cells and bronchial epithelial Clara cells. Furthermore, bronchoalveolar lavage fluid (BAL) from TO fetuses at day 28 induced significantly more type II cell apoptosis in vitro compared with control BAL, an effect that was inhibited by neutralizing anti-FasL antibody.

Conclusions

Our findings show that TO results in time-specific increase of both cellular and soluble FasL in fetal lungs and implicate the Fas/FasL pathway as a pivotal autocrine and/or paracrine regulator of TO- induced type II cell apoptosis.     

The evaluation of Fas/Fas ligand system in renal cell carcinoma--the effect of preoperative interferon-alpha therapy

OBJECTIVES: In order to investigate the effect of preoperative interferon (IFN)-alpha on Fas/Fas ligand (FasL) system, we examined Fas and FasL expression and the occurrence of apoptotic cell death in a preoperative therapy group, and in a control group using surgically resected renal cell carcinoma (RCC) tissues. METHODS: Ten cases were served as the preoperative therapy group, and sixteen cases as the control group. IFN-alpha was administered at five megaunits daily intramuscularly for two weeks in the preoperative therapy group. Immunohistochemistry for Fas and FasL, and terminal-deoxynucleotidyl-transferase (TdT)-mediated digoxigenin-dUTP nick end-labeling (TUNEL) were employed. We defined the labeling index (LI) as percentage of Fas- or FasL-positive cells in carcinomatous cells, and apoptotic index (AI) as percentage of TUNEL-positive cells in carcinomatous cells. RESULTS: Significant correlations were found between the LIs of Fas and AIs in all 26 cases. LIs of Fas and AIs of the preoperative therapy group were significantly higher than those of the control group. FasL expression was detected in nine out of ten cases in the preoperative therapy group, and in fourteen out of sixteen cases in the control group. There were no significant differences in LIs of FasL between two groups. CONCLUSION: These data suggest that apoptosis via the Fas/FasL system is functional, and that preoperative IFN-alpha treatment may up-regulate the Fas/FasL system in RCC. On the other hand, we need to investigate about an immune-escape mechanism through the FasL expression considering the relatively frequent expression of FasL in our results in RCC from now.     

Induction of cathelicidin in normal and CF bronchial epithelial cells by 1,25-dihydroxyvitamin D3

BACKGROUND: Antimicrobial peptides (AMPs) such as cathelicidins contribute to initial defense of the airway against inhaled pathogens. Recent studies have shown that the hormonally active form of vitamin D(3), 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) up-regulates AMP gene expression in several established cell lines. Furthermore, serum levels of vitamin D are often deficient in cystic fibrosis (CF) patients. METHODS: We investigated the effect of 1,25(OH)(2)D(3) on AMP mRNA levels in primary cultures of normal human bronchial epithelial (NHBE) cells by real-time PCR, and protein levels by Western blot. Antimicrobial activity of airway surface fluid from these cells was measured by in vitro assay against laboratory strains of bacteria. RESULTS: Treatment of NHBE cells with 1,25(OH)(2)D(3) (10(-8)M), resulted in a 10-fold up-regulation of cathelicidin mRNA levels after 12 h, which was augmented 2-fold with co-incubation of 1 mM Calcium. Moreover, 1,25(OH)(2)D(3) induced antimicrobial activity against the airway pathogens Bordetella bronchiseptica and Pseudomonas aeruginosa. 1,25(OH)(2)D(3) induced cathelicidin mRNA expression equally in both normal and CF bronchial epithelial cells. CONCLUSIONS: Elucidation of the effect of 1,25(OH)(2)D(3) on cathelicidin expression in NHBE cells and CF bronchial epithelial cells will aid in the development of novel therapeutic agents for treatment of airway infections in CF.