内脏脂肪素对巨噬细胞MMP-9的作用及其机制探讨

目的 研究内脏脂肪素（visfatin）对巨噬细胞基质金属蛋白酶-9（MMP-9）的作用及其机制。方法体外诱导THP-1单核细胞转化为巨噬细胞。为明确visfatin对MMP-9的作用,细胞分为两组：①巨噬细胞+visfatin 12 h组;②巨噬细胞+visfatin24 h组,两组的visfatin的质量浓度均为：0（对照组）、50、100、200、400 ng/mL。采用RT-PCR和Western blotting测定MMP-9基因和蛋白表达,明胶酶谱法检测MMP-9的活性。为明确visfatin对MMP-9的作用机制,细胞分为五组：①巨噬细胞未加刺激组（对照组）;②巨噬细胞+ MAPK p38、ERK1/2、JNK信号通路抑制剂预处理1 h后加visfatin（200 ng/mL）24 h组;③巨噬细胞+过氧化物酶体增殖剂活化受体（PPARγ）天然及人工配体/ RXR配体预处理1 h后加visfatin（200 ng/mL）24 h组;④巨噬细胞+visfatin（200 ng/mL）24 h组（Vis200组）;⑤巨噬细胞+visfatin（200 ng/mL）刺激不同时间组（5、10、15、30、60 min）。Western blotting检测MMP-9蛋白和PPARγ蛋白表达及visfatin刺激下巨噬细胞p38、ERK1/2、JNK MAPK磷酸化水平。结果 Visfatin能促进MMP-9基因及蛋白表达（P<0.05,P<0.01）,同时增强了MMP-9的活性（P<0.01）。p38 MAPK、ERK1/2 MAPK通路抑制剂及RXR配体抑制visfatin对MMP-9表达具有上调作用;visfatin能促进p38 MAPK和ERK1/2 MAPK的磷酸化,但不影响PPARγ蛋白的表达。结论 Visfatin增加了巨噬细胞炎症因子的表达,该作用与p38 MAPK和ERK1/2MAPK信号通路有关;RXR可能参与了该过程。     

Tagging single nucleotide polymorphisms in the PPAR-γ and RXR-α gene and type 2 diabetes risk:a case-control study of a Chinese Han population

Peroxisome proliferator-activated receptor (PPAR-γ),which is mainly involved in adipocyte differentiation, has been suggested to play an important role in the pathogenesis of insulin resistance and atherosclerosis. We investigated the frequencies of two common tagging polymorphisms of the PPAR-γ gene and two of PPAR-α with minor allele frequency (MAF)≥ 0.05 in the Chinese Han population and analyzed the correlation between the different genotypes and the risk of type 2 diabetes mellitus (T2DM). TaqMan assay was performed to test the genotypes in T2DM patients (n = 1,105) and normal controls (n = 1,107). Serum adiponectin concentration was measured by ELISA kit. The variant genotypes rs17817276GG, rs3856806CT and rs3856806CT/TT of PPAR-γ were associated with T2DM, P = 0.023,0.037 and 0.018, respectively. Furthermore, the prevalence of haplotype GT in PPAR-γ was less frequent in the case subjects (0.3%) than in the controls (1.9%) [P < 0.001,OR(95%CI)=0.13 (0.06-0.31)]. Patients with genotype TT of rs3856806 had a higher serum level of adiponectin than those with the genotype CC and CT (P = 0.031 and 0.038, respectively). There was no statistically significant difference between patients and controls in genotype distribution of rs6537944 and rs1045570 of the RXR-α gene. The present study suggests that the variant genotypes in the PPAR-γ gene could decrease the risk for the development of T2DM in the Chinese Han population.     

RXRγ、RARβ在9-cis-RA抑制人胃癌SGC7901细胞生长中的作用

目的:探讨维甲类X受体(RXR)γ、RARβ在RXR激动剂9-顺维甲酸(9-cis-RA)抑制人胃癌SGC7901细胞生长中的作用.方法:体外培养SGC7901细胞给予9-cis-RA干预,四甲基偶氮唑蓝(MTT)法、流式细胞术、HE染色、免疫组化染色、Western-blot检测9-cis-RA作用后SGC7901细胞生长情况、凋亡率、细胞周期的改变、RXRγ及RARβ表达情况.结果:SGC7901细胞与9-cis-RA共同培养48 h后,肿瘤细胞生长受到抑制,其作用具有浓度及时间依赖性.流式细胞仪检测显示处于G0/G1期的细胞增多,凋亡率增高,免疫组化及Western-blot 检测显示20 μmol/L 的9-cis-RA 作用72 h后,RXRγ、RARβ蛋白表达增加.结论:9-cis-RA可通过上调RXRγ、RARβ蛋白表达诱导细胞凋亡从而抑制人胃癌SGC7901细胞生长.     

Gene profiles of a human bronchial epithelial cell line after in vitro exposure to respiratory (non-)sensitizing chemicals: Identification of discriminating genetic markers and pathway analysis

Respiratory sensitization is a concern for occupational and environmental health in consumer product development. Despite international regulatory requirements there is no established protocol for the identification of chemical respiratory sensitizers. New tests should be based on mechanistic understanding and should be preferentially restricted to in vitro assays. The major goal of this study was to investigate the alterations in gene expression of human bronchial epithelial (BEAS-2B) cells after exposure to respiratory sensitizers and respiratory non-sensitizing chemicals, and to identify genes that are able to discriminate between both groups of chemicals. BEAS-2B cells were exposed during 6, 10, and 24 h to the respiratory sensitizers ammonium hexachloroplatinate IV, hexamethylene diisocyanate, and trimellitic anhydride, the irritants acrolein and methyl salicylate, and the skin sensitizer 1-chloro-2,4-dinitrobenzene. Overall changes in gene expression were evaluated using Agilent Whole Human Genome 4× 44K oligonucleotide arrays. Fisher Linear Discriminant Analysis was used to obtain a ranking of genes that reflects their potential to discriminate between respiratory sensitizing and respiratory non-sensitizing chemicals. The 10 most discriminative genes were BC042064, A_24_P229834, DOCK11, THC2544911, DLGAP4, NINJ1, PFKM, FLJ10986, IL28RA, and CASP9. Based on the differentially expressed genes, pathway analysis was used to identify possible underlying mechanisms of respiratory sensitization. We demonstrated that in bronchial epithelial cells the canonical PTEN signaling pathway is probably the most specific pathway in the context of respiratory sensitization. Results are indicative that the BEAS-2B cell line can be used as an alternative cell model to screen chemical compounds for their respiratory sensitizing potential.     

口服异维A酸治疗痤疮的临床疗效及实验室研究

目的 :　研究口服异维A酸对痤疮患者体内雄激素受体的影响及临床疗效观察 ,进一步为维A酸类药物治疗痤疮提供理论依据。方法 :　采用放射配体方法测定实验组 (A组 )与对照组 (B组 )外周血雄激素受体 (AR)水平及痤疮患者服药后AR水平。临床疗效与传统常规治疗疗效对比。结果 :　服药后雄激素受体水平 6 0 8± 4 6位点 /细胞 ,较服药前的 72 9± 5 3位点 /细胞明显降低 (P <0 .0 5 ) ,但受体与雄激素的亲和力无改变 ,血清睾酮水平也无明显差异。治疗组与对照组临床疗效观察有显著差异(P <0 .0 1)。结论 :　口服异维A酸能降低AR水平 ,从而影响痤疮发病的各个环节     

RNA和蛋白合成抑制剂对RXR基因转录表达的影响

目的：了解ＲＮＡ和蛋白质合成抑制剂对维甲酸Ｘ受体表达的影响。方法：常规培养人真皮成纤维细胞，用ａｃｔｉｎｏｍｙｃｉｎ Ｄ及ｃｙｃｌｏｈｅｘｉｍｉｄｅ共同作用于细胞２，４，８ｈ，然后分离总ＲＮＡ，用Ｎｏｒｔｈｅｒｎ ｂｌｏｔ方法，与标记的ＲＸＲα、β探针进行杂交。结果：这些抑制剂对ＲＸＲα均无影响。虽然ａｃｔｉｎｏｍｙｘｉｎ Ｄ对ＲＸＲβ的表达无影响，但ａｃｔｉｎｏｍｙｃｉｎ Ｄ和ｃｙｃｌｏ－ｈｅｘ     

Influenza A whole virion vaccine induces a rapid reduction of peripheral blood leukocytes via interferon-α-dependent apoptosis

Infection with single strand RNA (ssRNA) viruses, such as influenza A virus, is known to induce protective acquired immune responses, including the production of neutralizing antibodies. Vaccination also causes a reduction in the number of peripheral blood leukocytes (PBL) shortly after inoculation, a result which may have undesirable adverse effects. The cellular mechanisms for this response have not been elucidated so far. Here we report that formalin-inactivated influenza A whole virus vaccine (whole virion) induces a significant decrease in PBL in mice 5–16 h after administration, whereas an ether-split vaccine (HA split) made from the same influenza virus strain does not induce a similar loss of PBL. Concordant with this reduction in the number of PBL, a rapidly induced and massive production of interferon (IFN)-α is observed when mice are injected with whole virion, but not with HA split vaccines. The role of Toll-like receptors (TLR), which are involved in signal transduction of influenza virus, and the subsequent induction of IFNα were confirmed using mice lacking TLR7, MyD-88, or IFNα/β receptor. We further demonstrated that the observed PBL loss is caused by apoptosis in an IFNα-dependent manner, and not by leukocyte redistribution due to chemokine signaling failure. These findings indicate that RNA-encapsulated whole virion vaccines can rapidly induce a loss of leukocytes from peripheral blood by apoptosis, which may modulate the subsequent immune response.     

Synthetic retinoid fenretinide in breast cancer chemoprevention

Preclinical models suggest that retinoids inhibit mammary carcinogenesis. The induction of apoptosis is a unique feature of fenretinide, the most-studied retinoid in clinical trials of breast cancer chemoprevention, owing to its selective accumulation in breast tissue and its favorable toxicological profile. In a Phase III breast cancer prevention trial, fenretinide showed a strong trend of reduction of incidence of second breast malignancies in premenopausal women, which was confirmed by 15 years of follow-up. This warrants further research on the mechanisms of action and potential efficacy of fenretinide and provides the rationale for a Phase III primary prevention trial in young women at high risk for breast cancer. This review will highlight the role of fenretinide in breast cancer chemoprevention.     

The synthetic retinoid ST1926 attenuates prostate cancer growth and potentially targets prostate cancer stem‐like cells

Retinoids are vitamin A derivatives that regulate crucial biological processes such as cellular proliferation, apoptosis, and differentiation. The use of natural retinoids in cancer therapy is limited due to their toxicity and the acquired resistance by cancer cells. Therefore, synthetic retinoids were developed, such as the atypical adamantyl retinoid ST1926 that provides enhanced bioavailability and reduced toxicity. We have assessed the in vitro and in vivo antitumor properties and mechanism of action of ST1926 in targeting cancer stem‐like cells population of human prostate cancer (PCa) cell lines, DU145 and PC3, and mouse PCa cell lines, PLum‐AD and PLum‐AI. We demonstrated that ST1926 substantially reduced proliferation of PCa cells and induced cell cycle arrest, p53‐independent apoptosis, and early DNA damage. It also decreased migration and invasion of PCa cells and significantly reduced prostate spheres formation ability in vitro denoting sufficient eradication of the self‐renewal ability of the highly androgen‐resistant cancer stem cells. Importantly, ST1926 potently inhibited PCa tumor growth and progression in vivo. Our results highlight the potential of ST1926 in PCa therapy and warrant its clinical development.