全反式维甲酸对酒精性肝损伤大鼠肝脏retinoids含量和CYP2E1表达的影响

目的:研究补充小剂量全反式维甲酸(ATRA)对酒精喂养大鼠肝脏维生素A类物质(reti- noids,主要是维生素A和RA)含量、维生素A类物质极性代谢产物(PRMs)形成,细胞色素P4502E1(CYP2E1)表达和肝细胞损伤的影响。方法:将30只SD大鼠随机分为A组(正常对照组),B组(单纯乙醇组)、C组(无水乙醇8 g/kg ig8wk+150μg/kg ATRA)、D组(无水乙醇8 g/kg ig 8 wk+1.5 mg/kg ATRA ig 4 wk)四组.光镜下观察肝组织病理变化,高效液相色谱(HPLC)技术测定肝组织中Vitamin A类物质(retinoids)的含量,Western blotting检测肝脏CYP2E1的表达.结果:B组大鼠肝脏RA、维生素A(Retinol)和维生素A棕榈酸酯(retinyl palmitate)与A组相比含量显著降低(0.077±0.029 nmol/g vs 0.183±0.037 nmol/g,8.13±1.379 nmol/g vs 21.43±2.944 nmol/g,132.6±6.472 nmol/g vs 221.1±10.35 nmol/g,P<0.01),且肝脏中出现明显的PRMs.C组RA和Retinol含量恢复至A组水平,retinyl palmitate含量也部分恢复.D组RA和retinyl Dalmilate完全恢复至正常水平,而Retinol水平较A组升高(27.26±3.149 nmol/g vs 21.43±2.944 nmol/g,P<0.05).两种剂量的ATRA均可完全阻止PRMs形成.病理组织学检查显示补充ATRA可明显减轻肝细胞肿胀、脂肪变性,但对CYP2E1的表达没有明显影响。结论:小剂量ATRA能恢复酒精性肝病(ALD)大鼠肝脏retinoids含量,阻止PRMs产生,从而减轻肝细胞损伤.

Study on 3D-QSAR of Retinoids 3D-Interaction between Retinoids and their Receptor **

Fast and precise prediction of the receptor-ligand binding constant is an important aspect of structure-based drug design. Almost all de novo design methods or 3D database search methods tend to structure generation instead of structure evaluation. In this article, epididymal retinoic acid binding protein (ERABP) was used as a template to simulate the interaction between retinoids and their receptor. We deduced an equation predicting the drug-receptor binding constant. Furthermore, the conformers after docking were used in CoMFA analysis to get a pharmacophore model of this series of compounds.

Study on the Equivalent Conformation of Retinoids

N-(4-Carboxy-phenyl)-3,5-di-t-butyl-4-hydroxy-benzamide (2) possesses structural prerequisite for cell differentiation inducing activity, which constitutes the therapeutic basis of all trans retinoic acid (ATRA) and analogues for the treatment of cancer and dermatosis. In addition to the similarity of the disposition of functional groups with ATRA, 2 shows a conformational equivalence to ATRA in terms of molecular shape, size, as well as the spatial arrangement of functional groups. However, the N methylated compound (3) is devoid of the activity. It owes the biological behavior to the conformational difference, because of the steric interference between N methyl group and the hydrogen atom of a phenyl ring. X ray crystallography, UV, and NMR were performed to investigate the difference.

Potential therapeutic roles of retinoids for prevention of neuroinflammation and neurodegeneration in Alzheimer’s disease

All retinoids, which can be natural and synthetic, are chemically related to vitamin A. Both natural and synthetic retinoids use specific nuclear receptors such as retinoic acid receptors and retinoid X receptors to activate specific signaling pathways in the cells. Retinoic acid signaling is extremely important in the central nervous system. Impairment of retinoic acid signaling pathways causes severe pathological processes in the central nervous system, especially in the adult brain. Retinoids have major roles in neural patterning, differentiation, axon outgrowth in normal development, and function of the brain. Impaired retinoic acid signaling results in neuroinflammation, oxidative stress, mitochondrial malfunction, and neurodegeneration leading to progressive Alzheimer’s disease, which is pathologically characterized by extra-neuronal accumulation of amyloid plaques(aggregated amyloid-beta) and intra-neurofibrillary tangles(hyperphosphorylated tau protein) in the temporal lobe of the brain. Alzheimer’s disease is the most common cause of dementia and loss of memory in old adults. Inactive cholinergic neurotransmission is responsible for cognitive deficits in Alzheimer’s disease patients. Deficiency or deprivation of retinoic acid in mice is associated with loss of spatial learning and memory. Retinoids inhibit expression of chemokines and neuroinflammatory cytokines in microglia and astrocytes, which are activated in Alzheimer’s disease. Stimulation of retinoic acid receptors and retinoid X receptors slows down accumulation of amyloids, reduces neurodegeneration, and thereby prevents pathogenesis of Alzheimer’s disease in mice. In this review, we described chemistry and biochemistry of some natural and synthetic retinoids and potentials of retinoids for prevention of neuroinflammation and neurodegeneration in Alzheimer’s disease.

Effect of ATRA on Contents of liver Retinoids, Oxidative Stress and Hepatic Injury in Rat Model of Extrahepatic Cholestasis

The effects of all-trans-retinoic acid （ATRA） administration on the concentration of retinoids （RA and vitamin A） in liver, oxidative stress and the hepatic injury in a rat model of common bile duct ligation （CBDL）-induced liver injury were investigated. Female rats were subjected to a sham （n=5） or CBDL （n=48）. Two weeks after operation, rats undergoing CBDL were randomized to receive treatment with either ATRA at three different doses （0.1, 1.5, 7.5 mg/kg） dissolved in bean oil or only bean oil every day over a 4-week experimental period. Rats were killed and blood samples were collected from the heart for determination of the serum transaminase. The contents of retinoids in rat liver were detected by using HPLC. Malondialdehyde （MDA）, glutathione （GSH） and superoxide dismutase （SOD） levels in liver were determined by a spectrophotometric method according to the instruction of the kits. Liver pathologic changes were observed under the light microscopy and electron microscopy. The results showed that compared with sham-operated group, the levels of retinoids in the liver tissue were significantly decreased in the CBDL group （P〈0.01）. ATRA （0.1 mg/kg） administration in CBDL rats partially restored the contents of retinoids （P〈0.05）. Liver RA and vita- min A contents in CBDL group were significantly increased after ATRA （1.5 and 7.5 mg/kg） supplementation as compared with sham-operated group （P〈0.05）. However, in ATRA-treated CBDL group, hepatic GSH level and SOD activity, depressed by CBDL, and hepatic MDA level, increased by CBDL were returned to those in sham-operated group （P〈0.05）. The histologic observation of liver tissues indicated that ATRA treatment notably alleviated hepatocellular swelling, steatosis, the. swelling of mitochondria and proliferation of smooth endoplasmic reticulum （SER）. Treatment with ATRA could reduce levels of serum transaminase as compared with sham-operated group, more greatly in 1.5 and 7.5 mg/kg ATRA-treated groups than in 0.1 mg/kg ATRA-treated group. It was concluded that ATRA treatment can recover MDA and GSH levels and SOD activity in CBDL rat liver through restoring RA and vitamin A contents, and eventually ameliorate liver injury.

Involvement of serum retinoids and Leiden mutation in patients with esophageal, gastric, liver, pancreatic, and colorectal cancers in Hungary

AIM: To analyze the serum levels of retinoids and Leiden mutation in patients with esophageal, gastric, liver,pancreatic, and colorectal cancers.METHODS: The changes in serum levels of retinoids (vitamin A, α- and β-carotene, α- and β-cryptoxanthin,zeaxanthin, lutein) and Leiden mutation were measured by high liquid performance chromatography (HPLC)and polymerase chain reaction (PCR) in 107 patients (70 males/37 females) with esophageal (0/8), gastric (16/5), liver (8/7), pancreatic (6/4), and colorectal (30/21including 9 patients suffering from in situ colon cancer)cancer. Fifty-seven healthy subjects (in matched groups)for controls of serum retinoids and 600 healthy blood donors for Leiden mutation were used.RESULTS: The serum levels of vitamin A and zeaxanthin were decreased significantly in all groups of patients with gastrointestinal (GI) tumors except for vitamin A in patients with pancreatic cancer. No changes were obtained in the serum levels of α- and β-carotene,α- and β-cryptoxanthin, zeaxanthin, lutein in patients with GI cancer. The prevalence of Leiden mutation significantly increased in all groups of patients with GI cancer.CONCLUSION: Retinoids (as environmental factors)are decreased significantly with increased prevalence of Leiden mutation (as a genetic factor) in patients before the clinical manifestation of histologically different (planocellular and hepatocellular carcinoma, and adenocarcinoma) GI cancer.

Combination therapies improve the anticancer activities of retinoids in neuroblastoma

Most therapeutic protocols for child cancers use cytotoxic agents which have a narrow therapeutic index,and resulting in severe acute and chronic toxicities to normal tissues. Despite the fact that most child cancer patients achieve complete remission after chemotherapy,death still occurs due to relapse of persistent minimal residual disease(MRD) which remaining after initial cytotoxic chemotherapy. Advanced neuroblastoma(NB) is a leading cause of cancer deaths in young children. Retinoids are an important component of advanced NB therapy at the stage of MRD,yet half of all patients treated with 13-cis-retinoic acid still relapse and die. More effective combination therapies,with a lower side-effect profile,are required to improve outcomes for NB. Fenretinide or N-4-hydroxyphenyl retinamide is a synthetic derivative of retinoic acid which works on cancer cells through nuclear receptor-dependent and-independent signalling mechanisms. Moreover,several histone deacetylase inhibitors have entered early phase trials,and,suberoylanilide hydroxamic acid has been approved for use in adult cutaneous T cell lymphoma. A number of studies suggest that retinoid signal activation is necessary for histone deacetylase inhibitor activity. A better understanding of their mechanism of actions will lead to more evidence-based retinoid combination therapies.

RETINOIDS AND THEIR APPLICATIONS IN CLINIC

This review provides an overview of relevant aspects of retinoid physiology and molecular biology, and summarizes the current status of clinical investigations on the use of retinoid for the treatment of malignancies. The mechanism underlying the anticarcinogenic activity of retinoids appears to be associated with the ability of retinoids to modulate the growth and induce differentiation, and apoptosis of normal, premalignant, and malignant cells in vitro and in vivo. Retinoid effects seem to be resulted from changes in gene expression mediated via specific nuclear receptors (termed retinoic acid receptors, RAR-a, -b and -g). Chromosome translocations play an important role in APL pathogenesis. In the classical translocation, RAR a gene is fused with PML gene to form PML-RAR a chimeric gene, which is expressed in over 95% of the APL patients with t (15; 17) (q22; q21). Therefore, PML-RAR a fusion gene is the molecular marker of APL. ATRA can induce relocalization of the PML and restore the normal structure of POD. Furthermore, it could cause a degradation of PML-RAR a. In addition to the very high clinical response rate for APL patients treated with ATRA, clinical responses have been observed for patients with myelodysplastic syndrome, cutaneous T-cell lymphoma and skin cancers. Applications of retinoids are reviewed in different malignancies: including skin cancer, head and neck carcinoma, neuroblastoma, lung cancer, breast cancer, prostate cancer, bladder cancer and ovarian cancer in vivo and in vitro studies. The results indicate that retinoids are potentially useful agents for cancer prevention. RA combined with IFNs or RA combined with G-CSF has synergistic effect in inducing differentiation of cell growth. From current clinical results at least four leads are expected to impact on clinical development of retinoids in future: (1) development of retinoid receptor-selective agents; (2) investigation on cross-talk among members of the steroid superfamily; (3) strategies for attaining sufficient tissue levels of retinoids; (4) combined use with other differentiation or chemotherapeutic agents.

RETINOIC ACID NUCLEAR RECEPTORα (RARα),A MAJOR ROLE IN MEDIATING RETINOIDS INHIBITION OF GROWTH IN HUMAN BREAST CARCINOMA CELLS

Retinoids mediate their actions via RARs(retinoic acid receptors)and RXRs(retinoid X receptors).Each classes of these nuclear retinoid receptor is further subdiviede into three species namelyα,βand γ.Recent studies demonstrate that ER-positive HBC cell lines are sensitive and ER-negative cell lines are resistant to growth inhibitory effects of retinoic acid(RA). In this study we look at the expresion of RARs and RXRs in 6 HBC cell lines, we found only RARαmRNA level was strong correlated with ER-status. To further inestigate the major role of RARαin retinoidmediated inhibition of growth, we transfected RARαcDNA in two RA-resistant ER-negative HBC cell lines.Analyses of different clonal populations of RARα transfectants from each cell line revealed growth inhibition by retinoids. Our results demonstrates that RARα Plays a major role in mediating retinoids inhibition of growth in HBC cells and adequate levels are required for such actions.

Retinoids——癌症化学预防剂

RetinoJds(RNDs)指天然或合成的各种维生素A(VA)的代谢物或类似物．包括维甲醇．维甲醛．维甲酸(rednoic acid．RA)及维胺酸维胺脂等．RA衍生物主要包括全反式RA(ATRA)．13-顺式RA(13CRA)．9-顺式RA(9CRA)、维胺酸维胺酷等：RNDs已有百年的历史．尤其近25年掀起了RNDs革命．

EFFECT OF HYDROGEN BONDING ON DIRECTION OF PHOTOISOMERIZATION OF RETINOIDS:THE ORIGIN OF THE SOLVENT POLARITY EFFECT.

Studies of direction of photoisomerization of retinal,retinonitrile,a- retinonitrile and a trienenitrile analog in different solvents with varying wave- lengths of excitation and reaction temperature led to the conclusion that the well known solvent dependent photochemistry of retinoids is due to selective excitation of the hydrogen bonded species.

Cancer Chemopreventive Retinoids: Validation and Analysis of in Vivo and in Vitro Bioassay Results

Several natural and synthetic retinoids (vitamin-A derived analogies) were examined for their potential anti-cancer activity in both in vivo animal models and a novel in vitro human keratinocyte clonal growth bioassay system. The natural retinoids included all-trans-retinoic (RA), 13-cis-retinoic acid, 4-oxoretinoic acid, and retinol. Among the synthetic retinoids tested were all trans N-(4-hydroxy(phenyl)retinamide, 3-substituted oxoretinoic acids, and 13 cis-N-ethylretinamide. The animal models employed were: 1) vitamin A-deficient hamster tracheal organ assay (HTOC);2) the benzo(α)pyrene-induced squamous metaplasia in a hamster tracheal organ system (BP-HTOC);3) the mouse skin tumor promoter (TPA)-induced ornithine decarboxylase enzyme assay(ODC);4) the mouse skin papilloma (MPA) assay;and 5) a novel retinoid bioassay in which retinoids display IC50 values to inhibit clonal growth of NHK. All-trans-RA, 4-oxoretinoic acid and retinol were consistently more active than any of the synthetic derivatives in all bioassays tested. A statistical model was developed and significant positive correlations were found between: 1) ED50 values in the HTOC system and reduction in TPA-induced ODC enzyme activity;2) tumors per animal in the MPA bioassay and suppression of TPA-induced ODC activity;and 3) a positive correlation between suppression of tumors per animal in the MPA assay, and retinoid inhibition of keratinocyte clonal growth. Test retinoids, were tested for their capacity to inhibit the clonal growth of a squamous carcinoma cell line (SCC-25), which were found to be 2 - 3 logs less sensitive for each tested retinoid than the corresponding activity against NHK cells. Antineoplastic retinoid drugs were reviewed.

Role of retinoids in the prevention and treatment of colorectal cancer

Vitamin A and its derivatives, retinoids, have been widely studied for their use as cancer chemotherapeutic agents. With respect to colorectal cancer(CRC), several critical mutations dysregulate pathways implicated in progression and metastasis, resulting in aberrant Wnt/β-catenin signaling, gain-of-function mutations in K-ras and phosphatidylinositol-3-kinase/Akt, cyclooxygenase-2 over-expression, reduction of peroxisome proliferatoractivated receptor γ activation, and loss of p53 function. Dysregulation leads to increased cellular proliferation and invasion and decreased cell-cell interaction and differentiation. Retinoids affect these pathways by various mechanisms, many involving retinoic acid receptors(RAR). RAR bind to all-trans-retinoic acid(ATRA) to induce the transcription of genes responsible for cellular differentiation. Although most research concerning the chemotherapeutic efficacy of retinoids focuses on the ability of ATRA to decrease cancer cell proliferation, increase differentiation, or promote apoptosis; as CRC progresses, RAR expression is often lost, rendering treatment of CRCs with ATRA ineffective. Our laboratory focuses on the ability of dietary vitamin A to decrease CRC cell proliferation and invasion via RAR-independent pathways. This review discusses our research and others concerning the ability of retinoids to ameliorate the defective signaling pathways listed above and decrease tumor cell proliferation and invasion through both RAR-dependent and RAR-independent mechanisms.

Transcriptome profiling and RXR gene family identification reveals the molecular mechanism of rapid aging after spawning of cuttlefish Sepiella japonica

Sepiella japonica is a worldwide marine cuttlefish species of high economic value.S.japonica routinely modifying behaviors in reproductive life,such as rapid aging until death after spawning,has been recognized in artificial breeding.However,reproductive behavior at the level of genes is rarely reported,thus,the research on the genetic basis of behavior,reproduction,and artificial breeding was limited.We applied RNA-seq in different stages of reproduction to investigate the reason of rapid aging after spawning,pre-maturity,pre-spawning after maturity,and post-spawning.The retinoid X receptor(RXR)gene family in S.japonica was identified,and 1343–1452 differentially expressed genes(DEGs)in all 3 stages of reproductive life were identified from pairwise m RNA comparisons.Furthermore,through the GO term and KEGG analysis,S.japonica could handle neuronal development and network formation before maturity and have a functional degradation of neural communication,signal transduction,vision,and gene expression after spawning.Eight Sj RXRαs have been identified and they played different roles in growth development or reproduction.Therefore,the regulation of several channels and receptors is the intrinsic molecular mechanism of rapid aging after spawning in S.japonica.This study revealed the survival strategy and provided fundamental data on the level of genes for understanding the reproductive behavior and the reproduction of S.japonica.

Synthesis and Physico-Chemical Characterizations of Novel Hydrazone Ligands and Their Metal Complexes against Hormone-Dependent and Independent Cancers

This work deals with the synthesis and physicochemical characterizations of a new group of novel retinoidal ligands and their metal complexes. Their in vitro anti-proliferative activities have shown that ligand L1 is effective against human breast cancer BT-20 and MCF-7 cell lines. At the same time, compound L2 exerts its effect on human prostate cancer PC-3 and human breast cancer MDA-MB-231 and MCF-7 cell lines respectively. The retinoid ligands exert their pleiotropic action toward retinoic acid receptors (RARs) than their metal complexes but all compounds exhibit concentration-dependent.

Preparation of 9,13-dicis double bonds locked retinoids

Synthesis of two retinoids in which the 9, 13-dicis double bonds were locked in cycloalkene or thiophene was described. The key steps were the Wittig olefination of phosphonium salt 3 and 23 with aldehyde 14, followed by carbonylation of vinyl bromide 17 and 24 with carbon monoxide in the presence of Pd(PPh3)4.

骨髓间充质干细胞向神经细胞定向分化的体外研究

目的 探讨骨髓间充质干细胞( marrow stromal stem cells,MSCs)向神经细胞定向分化中神经蛋白分子的表达情况。 方法 取第5～7代体外培养Wistar大鼠MSCs,以0 .5μmol/ L全反式视黄酸( all- trans retinoidacid,ATRA)预诱导2 4 h后,换用改良神经细胞培养基( modified neuronal medium,MNM)继续培养。在ATRA作用2 4 h及MNM作用2、6、9、18及36 h,免疫组织化学检测巢蛋白( Nestin)、神经元特异性核心抗原( neuron- specificnuclear protein,Neu N)、微管相关蛋白2 ( microtubule- associated protein 2 ,MAP- 2 )和胶质纤维酸性蛋白的表达情况。 结果 ATRA和MNM作用后,MSCs呈典型神经元样,伸出较多的突起和分支,形成网络。Nestin最先表达,ATRA作用2 4 h出现,Neu N其次,MNM作用2 h检测到,MAP- 2最晚,MNM作用9h检测到。Nestin在MNM作用18h后表达最强,其阳性率为92 .3%±3.4 % ;36 h后表达明显减弱,阳性率仅为12 .3%±3.4 % ,而其它标志蛋白则持续表达。 结论 ATRA和MNM能促进MSCs向神经前体细胞和神经元转化,神经蛋白分子的表达顺序与神经细胞发育过程一致。

Metabolic balancing acts of vitamin A in type-2 diabetes and obesity

Using mice that lack retinaldehyde dehydrogenase 1 gene(Raldh1-/-mice),Kierfer et al demonstrated that retinoids(metabolites of Vitamin A) play an important role in the regulation of cellular metabolisms and energetics.The Aldh1a1-/-mice were leaner and less prone to accumulate subcutaneous and visceral fat,and to acquire insulin resistance on high fat diet.Their lower fasting glucose levels concomitant with reduced hepatic expression of glucose 6-phosphatase and phosphoenol pyruvate carboxy kinase genes indicated that Aldh1a1-/-mice were defective in gluconeogenesis.These mice also had lower plasma levels of triglycerides,very low-density lipoprotein and lowdensity lipoprotein-triacylglycerol,while their skeletal muscles elicited higher expression of carnitine palmatoyl transferase,medium chain acyl-A dehydrogenase,peroxisome proliferation activated receptor(PPARα and PPARδ.Thus,the improved lipid and lipoprotein profiles of Raldh1a1-/-mice resulted from a combination of reduced lipogenesis and enhanced fatty acid oxidation by retinoids.The mechanistic details of how retinoids integrate fasting glucose,hepatic gluconeogenesis and adaptive thermogenesis independent of body mass deserve further study.

Role of nuclear receptors in breast cancer stem cells

The recapitulation of primary tumour heterogenity and the existence of a minor sub-population of cancer cells,capable of initiating tumour growth in xenografts on serial passages, led to the hypothesis that cancer stem cells(CSCs) exist. CSCs are present in many tumours, among which is breast cancer. Breast CSCs(BCSCs) are likely to sustain the growth of the primary tumour mass, as wellas to be responsible for disease relapse and metastatic spreading. Consequently, BCSCs represent the most significant target for new drugs in breast cancer therapy. Both the hypoxic condition in BCSCs biology and proinflammatory cytokine network has gained increasing importance in the recent past. Breast stromal cells are crucial components of the tumours milieu and are a major source of inflammatory mediators. Recently, the antiinflammatory role of some nuclear receptors ligands has emerged in several diseases, including breast cancer. Therefore, the use of nuclear receptors ligands may be a valid strategy to inhibit BCSCs viability and consequently breast cancer growth and disease relapse.

Growth Inhibition and Apoptosis Induced by Retinoic Acid Combined with Interferon Alpha-2a on Transitional Cell Carcinoma of Bladder

Objective:To identify new favorable agents and develop novel approaches for the chemoprevention and treatment of superficial bladder cancer and investigate the effects of combination of retinoids and interferon α-2a on growth inhibition and apoptosis induction in bladder cancer cell lines. Methods:Four bladder cancer cell lines,grade 1 to 3,and two retinoids,all-trans-retinoic acid(ATRA),9-cis retinoic acid(9cRA),combined with interferon α-2a(INF),were used in the study.We compared the competence of these agents to inhibit growth,induce apoptosis,affect the expression of nuclear retinoid receptors,and modulate STAT1 protein. Results: Most of the bladder cancer cell lines were resistant to the effect of ATRA and 9cRA on growth inhibition and apoptosis induction,even at higher concentration(10 -5M).The effects of ATRA and 9c RA on cell growth and apoptosis were enhanced by INF α- 2a. Combination of ATRA and IFNα-2a induced RARβ and Stat 1 expression in three bladder cancer cell lines. Conclusion:The results demonstrated that INFα-2a synergize with the inhibitory effect of ATRA and 9c RA on the growth inhibition and apoptosis of bladder cancer cells in vitro,which suggested that it has a potential interest for the treatment of transitional cell carcinoma of bladder.