A novel bystander effect involving tumor cell-derived Fas and FasL interactions following Ad.HSV-tk and Ad.mIL-12 gene therapies in experimental prostate cancer

To enhance the NK population induced by Herpes Simplex virus thymidine kinase (HSV-tk) gene transduction and ganciclovir (GCV) treatment, adenovirus-mediated (Ad) expression of IL-12 was added to Ad.HSV-tk + GCV as combination gene therapy. This approach resulted in improved local and systemic growth suppression in a metastatic model of mouse prostate cancer (RM-1). In vitro assay of tumor infiltrating lymphocytes noted superior lysis of both RM-1 and Yac-1 targets with combination therapy, but in vivo depletion of NK cells only negatively impacted on systemic growth inhibition. TUNEL assay of primary tumors noted induction of apoptosis between two and four times higher than controls lasting for 6-8 days post-vector injection. After demonstrating that Ad.HSV-tk/GCV and Ad.mIL-12-induced IFN-gamma independently up-regulated expression of FasL and Fas, respectively, studies examined tumor cell-mediated death through Fas/FasL-induced apoptosis as a mechanism of primary tumor growth suppression. In vitro, combination therapy at low vector doses resulted in synergistic growth suppression, which could be negated by the addition of anti-FasL antibody. In vivo co-inoculation of an adenovirus expressing soluble Fas resulted in combination therapy-treated tumors, which were three times larger than expected, and a reduction in apoptosis to baseline levels. In FasL knockout mice, combination therapy maintained the superior results experienced in wild-type mice, indicating that tumor cell, not host cell FasL, was responsible for Fas transactivation. Therefore, the combination of Ad.HSV-tk/GCV + Ad.mIL-12 results in enhanced local growth control via apoptosis due to tumor cell expression of Fas and FasL and improved anti-metastatic activity secondary to a strong NK response.     

干扰素α对慢性髓系白血病来源的树突状细胞表达Fas／FasL的影响

本研究探讨干扰素α对慢性髓系白血病（CML）来源的树突状细胞（DC）表达Fas／FasL的影响。在CML—DCs的培养液中除加入SCF，GM—CSF，TNF—α及IL-4外，还加入IFN—α。培养10-14天，除了鉴定细胞免疫表型和Ph^1染色体比例外，还应用流式细胞仪检测细胞表达Fas／FasL比例，用PI染色分析细胞凋亡，ELISA法检测上清液sFas含量。结果表明：加入IFN-α后，CML—DC共刺激分子的表达显著改善，Ph^1（＋）细胞比例随IFN—α浓度增加而减低；培养细胞Fas的表达上调，sFas含量却下降，FasL表达阴性，细胞凋亡比例增加。结论：IFN—α在改善CML-DC表型同时，可通过Fas途径促进Ph^1（＋）细胞凋亡，使Ph^1（-）细胞数量相对增加。     

Roles of Fas and Fas ligand during mammary gland remodeling

Mammary involution is associated with degeneration of the alveolar structure and programmed cell death of mammary epithelial cells. In this study, we evaluated the expression of Fas and Fas ligand (FasL) in the mammary gland tissue and their possible role in the induction of apoptosis of mammary cells. FasL-positive cells were observed in normal mammary epithelium from pregnant and lactating mice, but not in nonpregnant/virgin mouse mammary tissue. Fas expression was observed in epithelial and stromal cells in nonpregnant mice but was absent during pregnancy. At day 1 after weaning, high levels of both Fas and FasL proteins and caspase 3 were observed and coincided with the appearance of apoptotic cells in ducts and glands. During the same period, no apoptotic cells were found in the Fas-deficient (MRL/lpr) and FasL-deficient (C3H/gld) mice. Increase in Fas and FasL protein was demonstrated in human (MCF10A) and mouse (HC-11) mammary epithelial cells after incubation in hormone-deprived media, before apoptosis was detected. These results suggest that the Fas-FasL interaction plays an important role in the normal remodeling of mammary tissue. Furthermore, this autocrine induction of apoptosis may prevent accumulation of cells with mutations and subsequent neoplastic development. Failure of the Fas/FasL signal could contribute to tumor development.     

Transmission of apoptosis in human colorectal tumor cells exposed to capecitabine,Xeloda, is mediated via Fas

We developed an original in vitro model dedicated to the exploration of molecular pharmacology of the new oral fluoropyrimidine capecitabine (Xeloda). More specifically, in this report, we investigated whether apoptosis induced by capecitabine was mediated by the Fas/FasL system. To achieve this goal, a specific in vitro coculture model mixing hepatoma and human colorectal cell line was used. A bystander effect was observed between HepG2 and LS174T cells treated with capecitabine. Besides this, Xeloda showed a 7-fold higher cytotoxicity and markedly stronger apoptotic potential in thymidine phosphorylase (TP)-transfected LS174T-c2 cells. The striking enhancement of thymidylate synthase inhibition that we observed in cells with high TP activity was most probably at the origin of the potentiation of capecitabine antiproliferative efficacy. In addition, this increase of sensitivity was accompanied by a strong overexpression of the CD95-Fas receptor on the cell surface. Both Fas and FasL mRNA expression were triggered after exposing TP+ cells to the drug. This implication of Fas in Xeloda-induced apoptosis was next confirmed by using antagonistic anti-Fas and anti-FasL antibodies that proved to reverse capecitabine antiproliferative activity, thus highlighting the key role that Fas could play in the optimization of an antitumor response to fluoropyrimidine drugs. Our data, therefore, show that TP plays a key role in the capecitabine activity and that the Fas/FasL system could be considered as a new determinant for Xeloda efficacy.     

Inflammation,Apoptosis, and Necrosis Induced by Neoadjuvant Fas Ligand Gene Therapy Improves Survival of Dogs With Spontaneous Bone Cancer

Fas ligand (FasL) gene therapy for cancer has shown promise in rodents; however, its efficacy in higher mammals remains unknown. Here, we used intratumoral FasL gene therapy delivered in an adenovirus vector (Ad-FasL) as neoadjuvant to standard of care in 56 dogs with osteosarcoma. Tumors from treated dogs had greater inflammation, necrosis, apoptosis, and fibrosis at day 10 (amputation) compared to pretreatment biopsies or to tumors from dogs that did not receive Ad-FasL. Survival improvement was apparent in dogs with inflammation or lymphocyte-infiltration scores >1 (in a 3-point scale), as well as in dogs that had apoptosis scores in the top 50th percentile (determined by cleaved caspase-3). Survival was no different than that expected from standard of care alone in dogs with inflammation scores ≤1 or apoptosis scores in the bottom 50th percentile. Reduced Fas expression by tumor cells was associated with prognostically advantageous inflammation, and this was seen only in dogs that received Ad-FasL. Together, the data suggest that Ad-FasL gene therapy improves survival in a subset of large animals with naturally occurring tumors, and that at least in some tumor types like osteosarcoma, it is most effective when tumor cells fail to express Fas.     

中性粒细胞凋亡调控基因表达异常在全身炎症反应综合征中的作用

目的观察全身炎症反应综合征（SIRS）时中性粒细胞（PMN）凋亡的异常变化及其凋亡调控基因的表达情况，评价其临床意义。方法8例SIRS患者（均为急性胰腺炎患者）作为SIRS组。6名健康献血者作为正常对照组。分别观察两组外周血PMN凋亡率、凋亡调控基因Fas／FasL和凋亡信号转导分子天冬氨酸特异性半胱氨酸蛋白酶-3（caspase-3）及血清白细胞介素-6（IL-6）、IL8的水平。结果SIRS组外周血血清IL-6和IL-8水平均明显高于正常对照组（P均＜0．01）。SIRS组患者外周血PMN细胞凋亡率较正常对照组明显减少（P＜0．01）；两组PMN在体外培养24h后，用蛋白质免疫印迹法（Western blotting）没有检测到FasL表达；SIRS组患者外周血PMN的Fas、caspase-3表达水平与正常对照组比较明显降低（P均＜0．01）。结论SIRS患者存在PMN的凋亡异常和Fas、caspase-3表达水平下调，PMN凋亡延迟在SIRS的发生发展中有着重要意义。     

雷公藤内酯醇诱导T淋巴细胞凋亡时Fas/FasL的表达

目的 检测Fas/FasL在雷公藤内酯醇诱导的T淋巴细胞凋亡中的表达。 方法 培养人T淋巴细胞，10、20、30μg/L的雷公藤内酯醇分别刺激细胞4、8、16 h，流式细胞仪DNA分析、FITC-Annexin Ⅴ binding/PI染色检测细胞凋亡，Western blot分析检测Fas/FasL蛋白的表达。 结果 雷公藤内酯醇以剂量和时间依赖的形式诱导T细胞凋亡，雷公藤内酯醇诱导T细胞凋亡的同时伴随有Fas和FasL表达的上调，同样，雷公藤内酯醇诱导Fas和FasL表达呈现剂量和时间依赖性。结论 雷公藤内酯醇以剂量和时间依赖的形式诱导人T细胞凋亡，雷公藤内酯醇诱导T细胞凋亡的信号通路可能是通过Fas/FasL途径激活的。     

Differential expression of Fas (CD95) and Fas ligand on normal human phagocytes: implications for the regulation of apoptosis in neutrophils

Human neutrophils, monocytes, and eosinophils are known to undergo apoptotic cell death. The Fas/Fas ligand pathway has been implicated as an important cellular pathway mediating apoptosis in diverse cell types. We conducted studies to examine the importance of the Fas/FasL system in normal human phagocytes. Although Fas expression was detected on neutrophils, monocytes, and eosinophils, constitutive expression of FasL was restricted to neutrophils. The three types of phagocytes demonstrated differential sensitivity to Fas-induced apoptosis. Only neutrophils were highly susceptible to rapid apoptosis in vitro after stimulation with activating anti-Fas IgM (mAb CH-11). Fas-mediated neutrophil apoptosis was suppressed by incubation with G-CSF, GM-CSF, IFN-gamma, TNF-alpha, or dexamethasone, as well as the selective tyrosine kinase inhibitors, herbimycin A and genistein. Spontaneous neutrophil death in vitro was partially suppressed by Fas-Ig fusion protein or antagonistic anti-Fas IgG1 (mAb ZB4). In coculture experiments, neutrophils released a soluble factor inducing death in Fas-susceptible Jurkat cells via a mechanism sensitive to the presence of Fas-Ig or anti-Fas IgG1. Immunoblot analysis using specific anti- human FasL IgG1 (mAb No. 33) identified a 37-kD protein in lysates of freshly isolated neutrophils and a 30-kD protein in the culture supernatant of neutrophils maintained in vitro. Our results suggest that mature neutrophils may be irrevocably committed to autocrine death by virtue of their constitutive coexpression of cell-surface Fas and FasL via a mechanism that is sensitive to proinflammatory cytokines, glucocorticoids, and inhibitors of tyrosine kinase activity. Furthermore, neutrophils can serve as a source of soluble FasL, which may function in a paracrine pathway to mediate cell death.     

小鼠急性粒-单核白血病WEHI-3细胞表面免疫应答分子的表达与Fas配体功能研究

为了研究小鼠急性粒-单核白血病细胞株WEHI-3细胞表面免疫应答分子Fas、Fas配体(FasL)、CD80分子表达以及FasL的功能,应用流式细胞术检测WEHI-3细胞表面Fas、FasL和CD80分子表达情况,同时采用氚胸腺嘧啶核苷(3H-TdR)掺入法检测FasL功能。结果表明:WEHI-3细胞表面CD80和Fas表达率分别为(5.06±0.41)%、(6.75±2.31)%(n=5),但FasL表达率高达(63.73±5.23)%(n=5),当WEHI-3(效应细胞,E)和Fas+YAC-1细胞(靶细胞,T)以3∶1、10∶1和30∶1混合培养时,YAC-1细胞的凋亡率分别为(26±4.5)%,(35±3.2)%和(43±2.7)%(n=5)。结论:WEHI-3细胞高表达FasL,低表达Fas和CD80,并能诱导Fas+YAC-1细胞凋亡。     

特发性肺纤维化患者支气管/肺泡上皮细胞凋亡和Fas/FasL基因表达

目的：检测细胞凋亡、Fas/FasL mRNA及其蛋白在特发性肺纤维化患者肺泡/支气管上皮细胞的表达,探讨细胞凋亡和促凋亡信号在此疾病中的意义。方法：应用末端原位杂交（TUNEL）、原位杂交、免疫组化技术,对12例特发性肺纤维化患者的肺活检组织（IPF组）及10例正常肺组织（对照组）检测了细胞凋亡、Fas/FasL mRNA及其蛋白表达的变化。结果：特发性肺纤维化组肺泡/支气管上皮细胞凋亡指数上调,明显高于对照组（P〈0.01）;IPF组肺泡/支气管上皮细胞中Fas/FasL mRNA及其蛋白表达上调,高于对照组（P〈0.01）;IPF组肺泡/支气管上皮细胞凋亡指数与其Fas/FasL mRNA及蛋白表达之间均无明显相关（P〉0.05）。结论：肺纤维化时肺泡/支气管上皮细胞凋亡上调,Fas/FasL mRNA及其蛋白表达增强,在肺纤维化发生、发展中起重要作用。     

反转录病毒载体介导可溶性Fas的体外表达

将含全长FascDNA的质粒利用PCR技术进行特定片段删除 ,获得sFascDNA。通过DNA重组技术 ,将sFascDNA插入到反转录病毒载体 pLXIN ,构建了重组表达载体pLXIN sFas。经酶切鉴定及测序 ,表明成功地构建了重组表达载体 pLXIN sFas。该载体经PA317细胞包装后 ,感染靶细胞COS 7,分别采用ELISA及凋亡抑制实验检测其蛋白表达量为 (2 .2± 0 .7) μg/ml,且具有良好的生物学活性 ,能明显抑制抗 Fas(CH 11)介导的T淋巴瘤细胞株Jurkat的凋亡。这一结果为探讨Fas和FasL途径在白血病发生中的作用奠定了基础     

Eradication of breast cancer xenografts by hyperthermic suicide gene therapy under the control of the heat shock protein promoter

To investigate the usefulness of heat shock protein (HSP) promoter for breast cancer gene therapy, hyperthermia and HSV thymidine kinase (tk) suicide gene combination therapy was examined with mouse mammary cancer cell line FM3A. HSP promoter activity was markedly increased after heat shock (41-45 degrees C), with maximum activation (about 400-fold) at 3 hr. An in vitro cytotoxic assay showed that HSP-tk-transduced FM3A cells became more sensitive (more than 50,000 times) to ganciclovir (GCV) with heat shock, but untreated cells showed no increased cytotoxic sensitivity to GCV compared with control FM3A cells. In addition to promoter-oriented selective cell killing, a "chemosensitization effect" as a bystander effect was demonstrated by hyperthermia and suicide gene combination therapy, using a non-heat-inducible promoter. Immunohistochemical analysis revealed that this synergistic killing effect was dependent on apoptotic cell death with upregulation of both Fas and FasL (Fas ligand) expression. We also examined the efficacy of HSP-tk gene therapy in vivo by implanting breast cancer in subcutaneous and intraperitoneal models of BALB/c nude mice targeted by the HVJ-anionic liposome method. Significant tumor regression was observed in HSP-tk-transduced tumors followed by hyperthermia therapy, but no such inhibition was noted in either the mock vector transfection or hyperthermia group compared with control tumor-bearing mice. Our results demonstrate that this combination system is synergistically effective in mediating Fas-dependent apoptosis for a specific gene therapy targeting HSP-expressing mammary carcinomas, even in advanced and heat-resistant breast cancer.     

FAS,FASL及Bcl-2在化疗药物诱导RMA细胞凋亡过程中的表达

本研究通过测定RMA细胞Fas,FasL和Bcl-2表达的变化，探讨其在细胞凋亡过程中的作用。在培养的小鼠T淋巴瘤RMA细胞系中加化疗药物地塞米松（DEX）、足叶乙甙（VP－16）、三氧化二砷（As2O3)及维甲酸（ATRA）以及培养细胞中先分别与细胞国子IL－2，IL－6或GM－CSF共同培养后再加入上述药物，观察对细胞凋亡的影响及细胞凋亡过程中Fas,FasL mRNA,Fas及Bcl-2抗原的表达。DEX和VP－16能上调Fas和FasL表达，促进细胞凋亡，Bcl-2表达无变化。ATRA可下调Bcl-2表达，但不影响Fas和FasL系统，也未观察到有细胞凋亡。As2O3可以诱导细胞凋亡,但Fas,FasL及Bcl-2表达均无变化。提示不同药物对一种细胞可能通过不同的信号途径诱导调亡，而Fas系统诱导的细胞凋亡需要Fas和FasL共同参与。单独用IL－2，IL－6或GM－CSF虽然使Fas蛋白增加，但不引起细胞凋亡；如同时并用IL－2和IL－6则Fas和FasL表达均上升，并诱导细胞凋亡。上述细胞因子与化疗药物并用时可减低药物量，促进药物的凋亡诱导作用。在无FasL表达情况下，抗Fas单克隆抗体能诱导RMA细胞凋亡。实验结果表明，细胞因子与化疗药物可协同作用诱导细胞凋亡，Fas-FasL系统参与DEX和VP－16诱导的RMA细胞凋亡过程，不同的药物可以通过不同的信号途径诱导细胞凋亡。     

Nonviral genetic transfer of Fas ligand induced significant growth suppression and apoptotic tumor cell death in prostate cancer in vivo

To accomplish efficient nonviral gene therapy against prostate cancer (PC), Epstein-Barr virus (EBV)-based plasmid vectors containing EBNA1 gene and oriP were employed and combined with a cationic polymer or cationic lipid. When EBV-plasmid/poly-amidoamine dendrimer complex was injected into PC-3-derived tumors established in severe combined immunodeficiency mice, a considerable expression of marker gene was obtained in the tumors, and the expression level was more than eight-fold higher than that achieved by conventional plasmid vector/dendrimer. Since most PC cells express the apoptotic signal molecule Fas (Apo-1/CD95) on their surface, Fas ligand (FasL) gene was transferred into PC cells to kill the tumor cells. In vitro transfection with pGEG.FasL (an EBV-plasmid with the FasL gene) significantly reduced the viability of PC cells, which subsequently underwent apoptosis. Intratumoral injections of pGEG.FasL into PC induced significant growth suppression of the xenograft tumors, in which typical characteristics of apoptosis were demonstrated by TUNEL staining and electron microscopic observations. When pGEG.FasL transfer was accompanied by systemic administrations of cisplatin, the tumors were inhibited even more remarkably, leading to prolonged survival of the animals. FasL gene transfection by means of EBV-based plasmid/cationic macromolecule complexes may provide a practical therapeutic strategy against PC.     

白血病细胞对Fas/FasL途径介导凋亡的抵抗及其应对策略

从细胞凋亡的角度看，造血细胞凋亡过少是造血细胞堆积的原因，Fas／FasL系统作为诱导细胞凋亡的一条重要途径，参与了白血病的发生发展。白血病细胞普遍存在对Fas／FasL途径介导的凋亡不敏感或抵抗，而这也是造成白血病细胞免疫逃逸和对化疗不敏感的重要原因之一。近年来，国内外对白血病Fas／FasL途径介导的凋亡抵抗的机制．诸如Fas／FasL突变及表达异常Fas信号传导途径异常，凋亡调控基因对Fas／FasL系统的调控（NF—KB、XiAP膜受体CD28和基质金属蛋白酶7等）和应对策略的相关研究取得了一些进展，现对上述有关问题作一综述。     

New disease-modifying antirheumatic drug 2 acetylthiomethyl-4-(4-methylphenyl)-4-oxobutanoic acid (KE-298) selectively augments activation-induced T cell death.

We examined in this study whether the newly developed disease-modifying antirheumatic drug (DMARD) 2-acetylthiomethyl-4-(4-methylphenyl)-4-oxobutanoic acid (KE-298) augments activation-induced T cell death. Peripheral blood (PB) T cells, isolated from healthy donors, were activated by incubation with interleukin-2 (IL-2) followed by further culture with 12-0-tetradecanoyl phorbol 13-acetate (PMA) and ionomycin in the presence or absence of KE-298. The apoptosis of activated T cells was examined by flow cytometric determination of hypodiploid DNA. Fas expression and caspase-3 activity in activated T cells were also examined by flow cytometry, and expression of Fas ligand (FasL), Bcl-2-related proteins, and X chromosome-linked inhibitor of apoptosis protein (XIAP) was determined by Western blot analysis. Apoptosis was not obvious in resting T cells and was not augmented by KE-298. In contrast, apoptosis was clearly detected in activated T cells (activation-induced T cell death) with the increment of caspase-3 activity, and incubation of these cells with KE-298 further enhanced apoptosis. Treatment of activated T cells with KE-298 increased Bax expression but decreased XIAP expression without affecting the expression of Fas/FasL. Thus caspase-3 activity in activated T cells appeared to be increased by KE-298. Our results suggest that the newly developed DMARD, KE-298, selectively augmented activation-induced T cell death. This finding may contribute to the therapeutic efficacy of KE-298 in rheumatoid arthritis (RA) patients and provide new insight into the pharmacologic action of DMARDs.     

依曲替酸上调Fas、FasL诱导皮肤鳞癌细胞凋亡的实验研究

目的：探讨依曲替酸通过上调Fas、FasL基因表达诱导皮肤鳞状细胞癌（鳞癌）细胞系SCC13细胞凋亡的作用。方法：以体外培养的人皮肤鳞癌细胞系SCC13细胞为研究对象,采用酶联免疫分析法（ELISA）、AnnxinV-FITC/PI法检测凋亡的诱导情况。用实时荧光定量RT-PCR方法检测Fas、FasL mRNA的表达。用Fas中和抗体ZB4检测Fas、FasL在依曲替酸诱导SCC13细胞凋亡中的作用。结果：依曲替酸能诱导SCC13细胞凋亡,并具有浓度及时间依赖性。依曲替酸能上调肿瘤细胞内Fas、FasL mRNA表达水平。单独应用依曲替酸的早期凋亡率为（16.76±1.04）%,与ZB4共同处理SCC13后,早期凋亡率下降为（7.12±0.85）%,ZB4显著阻断依曲替酸诱导的凋亡（P〈0.05）。结论：依曲替酸能诱导皮肤鳞状细胞癌细胞凋亡,其机制可能与Fas死亡受体信号转导途径有关。     

Functional expression of Fas and Fas ligand on human colonic intraepithelial T lymphocytes

The expression of Fas, a cell surface receptor directly responsible for triggering cell death by apoptosis, and its ligand (FasL) was investigated on both human colonic intraepithelial T lymphocytes (IELs) and peripheral blood mononuclear lymphocytes (PBMLs). FACS analysis indicated that IELs have increased expression of Fas compared with PBMLs, together with the progress activation marker, CD45RO. A discrete fraction of freshly isolated IELs also constitutively expressed FasL, perhaps as a result of recent in vivo activation. Using monoclonal antibody APO2.7, which detects mitochondrial 7A6 antigen specifically expressed by cells undergoing apoptosis, we further investigated the apoptosis-inducing effect of anti-Fas monoclonal antibody (CH11) on both IELs and PBMLs. FACS analysis revealed that CH11 increased the percentage of apoptotic cells, in IELs but not in PBMLs. Culture with anti-FasL monoclonal antibody (4H9) significantly recovered cell viability in IELs, but not in PBMLs. These results indicate that IELs constitutively express both Fas and FasL and that Fas crosslinking generates signals resulting in apoptosis, outlining a potential mechanism involved in intestinal tolerance.     

Matrix metalloproteinase inhibitors cause cell cycle arrest and apoptosis in glomerular mesangial cells

Inflammation is characterized by an excess of cell proliferation often leading to fibrosis and sclerosis with subsequent loss of organ function. We hypothesized that these features may be ameliorated by induction of cell cycle arrest and apoptosis as result of therapy with matrix metalloproteinase (MMP) inhibitors. In our study, mesangial cells and experimental mesangial proliferative glomerulonephritis provided the model of inflammation. First, we investigated the effect of the MMP inhibitor BB-1101 in anti-Thy1.1 nephritis. The numbers of apoptotic glomerular cells in nephritic rats increased about 4 and 6 times as a result of BB-1101 therapy, observed 11 and 14 days after induction of disease, respectively. Subsequently, rat mesangial cells were exposed to an MMP inhibitor in vitro. Fluorescence-activated cell sorter analyses of cells exposed to RO111-3456 demonstrated a dose-dependent cell cycle arrest in the G(0)/G(1) phase associated with increased expression of statin. The cell cycle arrest was followed by apoptosis as investigated by terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) biotin nick-end labeling (TUNEL) and acridine orange/ethidium bromide stainings, as well as by annexin V binding. The induction of p53, p21, and bax, but not the Fas/FasL pathway appeared to play an important pathogenetic role. In summary, MMP inhibitors induce cell cycle arrest followed by apoptosis in mesangial cells. These features help to explain the anti-inflammatory effects of these compounds, such as reduction of mesangial cell proliferation and attenuation of extracellular matrix accumulation. In conclusion, induction of cell cycle arrest with subsequent apoptosis may offer new perspectives in the therapy of inflammation even beyond kidney diseases.