CF102 an A3 adenosine receptor agonist mediates anti-tumor and anti-inflammatory effects in the liver.

The Gi protein-associated A(3) adenosine receptor (A(3) AR) is a member of the adenosine receptor family. Selective agonists at the A(3) AR, such as CF101 and CF102 were found to induce anti-inflammatory and anti-cancer effects. In this study, we examined the differential effect of CF102 in pathological conditions of the liver. The anti-inflammatory protective effect of CF101 was tested in a model of liver inflammation induced by Concanavalin A (Con. A) and the anti-cancer effect of CF102 was examined in vitro and in a xenograft animal model utilizing Hep-3B hepatocellular carcinoma (HCC) cells. The mechanism of action was explored by following the expression levels of key signaling proteins in the inflamed and tumor liver tissues, utilizing Western blot (WB) analysis. In the liver inflammation model, CF102 (100 µg/kg) markedly reduced the secretion of serum glutamic oxaloacetic transaminase and serum glutamic pyruvic transaminase in comparison to the vehicle-treated group. Mechanistically, CF102 treatment decreased the expression level of phosphorylated glycogen synthase kinase-3ß, NF-κB, and TNF-α and prevented apoptosis in the liver. This was demonstrated by decreased expression levels of Fas receptor (FasR) and of the pro-apoptotic proteins Bax and Bad in liver tissues. In addition, CF102-induced apoptosis of Hep-3B cells both in vitro and in vivo via de-regulation of the PI3K-NF-κB signaling pathway, resulting in up-regulation of pro-apoptotic proteins. Taken together, CF102 acts as a protective agent in liver inflammation and inhibits HCC tumor growth. These results suggest that CF102 through its differential effect is a potential drug candidate to treat various pathological liver conditions.

A review of the use of hormonal contraception in women with cardiovascular disease complications and risk factors. A systematic review.

INTRODUCTION: The Centers for Disease Control and Prevention (CDC) developed a point form guideline for the use of oral contraceptives in women with coexisting medical conditions. Although this acts as a guide, it leaves the clinician without an understanding of why they are doing what they are doing. EVIDENCE ACQUISITION: In this article, which is one of two articles addressing coexisting medical condition and oral contraceptive use, an update of the scientific knowledge is provided. EVIDENCE SYNTHESIS: The explanation of the guidelines are to be used as a supplement for those who desire more information than is found in the CDC guidelines and in general a review for clinicians dealing with women desiring hormonal contraception. CONCLUSIONS: The development of lower dose contraceptive pills as well as the increased incidence of comorbid conditions, such as metabolic syndrome, in younger women seeking contraception has brought along new research and new evidence to guide clinicians in the prescription of these medications.

A review of the use of hormonal contraception in women with non-cardiovascular coexisting medical conditions. A comprehensive review.

INTRODUCTION: Previously, the American College of Obstetrics and Gynecology (ACOG) had published an excellent practice bulletin addressing the use of hormone contraception in women with pre-existing medical conditions. This practice bulletin became out of date. The Centers for Disease Control and prevention (CDC) of the USA subsequently developed a point form guideline for the use of oral contraceptives in women with coexisting medical conditions. EVIDENCE ACQUISITION: Although this acts as a guide, it leaves the clinician without an understanding of why they are doing what they are doing. This article is one of two related to women with coexisting medical conditions. EVIDENCE SYNTHESIS: In this article we will provide an update of the scientific knowledge since the publication of the ACOG guideline (2006). It is to be used as a supplement for those who desire more information than that found in the CDC guidelines. CONCLUSIONS: Although some recommendations have remained unchanged over the years, the development of lower dose contraceptive pills as well as the increased incidence of comorbid conditions, such as metabolic syndrome, in younger women seeking contraception has brought along new research and new evidence to guide clinicians in the prescription of these medications.

The anti-inflammatory target A(3) adenosine receptor is over-expressed in rheumatoid arthritis, psoriasis and Crohn's disease.

The Gi protein associated A(3) adenosine receptor (A(3)AR) was recently defined as a novel anti-inflammatory target. The aim of this study was to look at A(3)AR expression levels in peripheral blood mononuclear cells (PBMCs) of patients with autoimmune inflammatory diseases and to explore transcription factors involved receptor expression. Over-expression of A(3)AR was found in PBMCs derived from patients with rheumatoid arthritis (RA), psoriasis and Crohn's disease compared with PBMCs from healthy subjects. Bioinformatics analysis demonstrated the presence of DNA binding sites for nuclear factor-kappaB (NF-kappaB) and cyclic AMP-responsive element binding protein (CREB) in the A(3)AR gene promoter. Up-regulation of NF-kappaB and CREB was found in the PBMCs from patients with RA, psoriasis and Crohn's disease. The PI3K-PKB/Akt signaling pathway, known to regulate both the NF-kappaB and CREB, was also up-regulated in the patients' PBMCs. Taken together, NF-kappaB and CREB are involved with the over-expression of A(3)AR in patients with autoimmune inflammatory diseases. The receptor may be considered as a specific target to combat inflammation.

A3 adenosine receptor: pharmacology and role in disease.

The study of the A(3) adenosine receptor (A(3)AR) represents a rapidly growing and intense area of research in the adenosine field. The present chapter will provide an overview of the expression patterns, molecular pharmacology and functional role of this A(3)AR subtype under pathophysiological conditions. Through studies utilizing selective A(3)AR agonists and antagonists, or A(3)AR knockout mice, it is now clear that this receptor plays a critical role in the modulation of ischemic diseases as well as in inflammatory and autoimmune pathologies. Therefore, the potential therapeutic use of agonists and antagonists will also be described. The discussion will principally address the use of such compounds in the treatment of brain and heart ischemia, asthma, sepsis and glaucoma. The final part concentrates on the molecular basis of A(3)ARs in autoimmune diseases such as rheumatoid arthritis, and includes a description of clinical trials with the selective agonist CF101. Based on this chapter, it is evident that continued research to discover agonists and antagonists for the A(3)AR subtype is warranted.

Adenosine receptors and cancer.

The A(1), A(2A), A(2B) and A(3) G-protein-coupled cell surface adenosine receptors (ARs) are found to be upregulated in various tumor cells. Activation of the receptors by specific ligands, agonists or antagonists, modulates tumor growth via a range of signaling pathways. The A(1)AR was found to play a role in preventing the development of glioblastomas. This antitumor effect of the A(1)AR is mediated via tumor-associated microglial cells. Activation of the A(2A)AR results in inhibition of the immune response to tumors via suppression of T regulatory cell function and inhibition of natural killer cell cytotoxicity and tumor-specific CD4+/CD8+ activity. Therefore, it is suggested that pharmacological inhibition of A(2A)AR activation by specific antagonists may enhance immunotherapeutics in cancer therapy. Activation of the A(2B)AR plays a role in the development of tumors via upregulation of the expression levels of angiogenic factors in microvascular endothelial cells. In contrast, it was evident that activation of A(2B)AR results in inhibition of ERK1/2 phosphorylation and MAP kinase activity, which are involved in tumor cell growth signals. Finally, A(3)AR was found to be highly expressed in tumor cells and tissues while low expression levels were noted in normal cells or adjacent tissue. Receptor expression in the tumor tissues was directly correlated to disease severity. The high receptor expression in the tumors was attributed to overexpression of NF-kappaB, known to act as an A(3)AR transcription factor. Interestingly, high A(3)AR expression levels were found in peripheral blood mononuclear cells (PBMCs) derived from tumor-bearing animals and cancer patients, reflecting receptor status in the tumors. A(3)AR agonists were found to induce tumor growth inhibition, both in vitro and in vivo, via modulation of the Wnt and the NF-kappaB signaling pathways. Taken together, A(3)ARs that are abundantly expressed in tumor cells may be targeted by specific A(3)AR agonists, leading to tumor growth inhibition. The unique characteristics of these A(3)AR agonists make them attractive as drug candidates.

The possible role of retinal dopaminergic system in visual performance.

It is a well-known fact that the retina is one of the tissues in the body, which is richest in dopamine (DA), yet the role of this system in various visual functions remains unclear. We have identified 13 types of DA retinal pathologies, and 15 visual functions. The pathologies were arranged in this review on a net grid, where one axis was "age" (i.e., from infancy to old age) and the other axis the level of retinal DA (i.e., from DA deficiency to DA excess, from Parkinson disorder to Schizophrenia). The available data on visual dysfunction(s) is critically presented for each of the DA pathologies. Special effort was made to evaluate whether the site of DA malfunction in the different DA pathologies and visual function is at retinal level or in higher brain centers. The mapping of DA and visual pathologies demonstrate the pivot role of retinal DA in mediating visual functions and also indicate the "missing links" in our understanding of the mechanisms underlying these relationships.

The A3 adenosine receptor agonist CF102 induces apoptosis of hepatocellular carcinoma via de-regulation of the Wnt and NF-kappaB signal transduction pathways.

The A3 adenosine receptor (A(3)AR) is highly expressed in tumors and was suggested as a target for cancer treatment. In this study, we show that A(3)AR is highly expressed in tumor tissues and in peripheral blood mononuclear cells (PBMCs) derived from patients with HCC, as well as from HCC tumor-bearing rats. The high expression level of the receptor was directly correlated to overexpression of NF-kappaB, known as a transcription factor of A(3)AR. CF102, a synthetic highly selective agonist to A(3)AR induced a marked dose response inhibition of tumor growth in N1S1 HCC tumor rats, via de-regulation of the NF-kappaB and the Wnt signal transduction pathways, resulting in apoptosis of tumor cells. Taken together, A(3)AR is highly expressed in tumors and PBMCs of HCC patients and tumor-bearing rats. CF102 induced apoptosis and tumor growth inhibition. These data suggest A(3)AR as a novel targeted therapy to treat HCC.

Long lasting effects of infancy iron deficiency--preliminary results.

The long-term effects of rehabilitated infancy (1 year old) iron deficiency (ID) were examined at age 10. The children were examined for the following variables: auditory system function, the level of morning cortisol, I.Q. score (WISC-R), and behavioral profile. The results indicate that while the former ID children's hearing system appears to function well, there was a delay in brain stem processing of the auditory signals. In addition, the level of morning cortisol was reduced, the general I.Q. scores were lower than the normal group (mainly in the performed subtest), and more sleep disturbances and fatigue during day were reported. These outcomes are consistent with established reports on the effect of iron deficiency on the rate of myelination in selected brain areas during critical period of 1 year olds. The findings of increased sleep disturbances and lower I.Q. tests require further study.

IB-MECA, an A3 adenosine receptor agonist prevents bone resorption in rats with adjuvant induced arthritis.

OBJECTIVES: The anti-inflammatory effect of adenosine is partially mediated via the A3 adenosine receptor (A3AR), a Gi protein associated cell surface receptor. The highly selective A3AR agonist, IB-MECA was earlier shown to prevent the clinical and pathological manifestations of arthritis in experimental animal models of collagen and adjuvant induced arthritis (AIA). In this study we tested the effect of IB-MECA on the prevention of bone resorption in AIA rats and looked at the molecular mechanism of action. METHODS: Rats with AIA were treated orally twice daily with IB-MECA starting upon onset of disease and the clinical score was evaluated every other day. At study termination the foot, knee and hip region of both vehicle and IB-MECA treated animals were subjected to histomorphometric analysis. Western blot analysis was carried out on paw protein extracts. RESULTS: IB-MECA ameliorated the clinical manifestations of the disease and reduced pannus and fibrosis formation, attenuated cartilage and bone destruction and decreased the number of osteoclasts. In cell protein extracts derived from paw of AIA rats, A3AR was highly expressed in comparison to naïve animals. In paw extracts derived from IB-MECA treated AIA rats, down-regulation of the A3AR protein expression level was noted. PI3K, PKB/Akt, IKK, NF-kappaB, TNF-alpha and RANKL were down-regulated whereas caspase 3 was up-regulated. CONCLUSION: IB-MECA, a small highly bioavailable molecule, induces modulation of proteins which control survival and apoptosis resulting in the amelioration of the inflammatory process and the preservation of bone mass in AIA rats.

Nutritional deficiencies in learning and cognition.

The postinfancy period is crucial for normal brain development, providing subsequent optimal conditions for learning and cognition. Both iron deficiency and essential fatty acids deficiency may impair normal neurological development. This review examines the limited number of studies that have been performed in preschool children and offers a broader view of the relationships among nutrition, nutrients and cognition.

Adenosine and other low molecular weight factors released by muscle cells inhibit tumor cell growth.

In this study, we investigated the basis of the resistance of muscles to tumor metastases. We found that a low molecular weight fraction (Mr <3000) of skeletal muscle cell-conditioned medium (MCM) markedly inhibits the proliferation of carcinoma, sarcoma, or melanoma cell lines in vitro. The MCM exerts a cytostatic effect on tumor cell growth and arrests the cells in G0/G1 of the cell cycle. However, normal cell proliferation of cells such as bone marrow cells or fibroblasts was found to be refractory to the influence of the MCM. A reduction in melanoma growth was observed in mice treated with the MCM. Adenosine was identified as one of the active components in the MCM by using high-performance liquid chromatography separations, mass spectra, and nuclear magnetic resonance analyses. At a concentration of 4 microM, equal to that found in the MCM, adenosine inhibits the proliferation of tumor cell lines (Nb2 lymphoma, K-562 leukemia, and LNCaP prostate carcinoma cells) while stimulating the proliferation of normal murine bone marrow cells. By similar methods, additional inhibitory components were detected in the MCM in a molecular mass range of 600-800 Da. The ability of adenosine and other low molecular weight components to specifically inhibit tumor cell growth in vitro and in vivo may account for the resistance of muscle to tumor metastases.

Essential fatty acids and the brain: from infancy to aging.

The major effects of essential fatty acids (EFA) on brain structure and functions are reviewed. EFA determine the fluidity of neuronal membrane and control the physiological functions of the brain. EFA is also involved in synthesis and functions of brain neurotransmitters, and in the molecules of the immune system. Since they must be supplied from the diet, a decreased bioavailability is bound to induce major disturbances. While the brain needs a continuous supply during the life span, there are two particularly sensitive periods-infancy and aging. EFA deficiency during infancy delays brain development, and in aging will accelerate deterioration of brain functions. In discussing the role of EFA two issues must be considered-the blood-brain barrier, which determines the bioavailability, and the myelination process, which determines the efficiency of brain and retinal functions.

Extensive genetic interactions between PRP8 and PRP17/CDC40, two yeast genes involved in pre-mRNA splicing and cell cycle progression.

Biochemical and genetic experiments have shown that the PRP17 gene of the yeast Saccharomyces cerevisiae encodes a protein that plays a role during the second catalytic step of the splicing reaction. It was found recently that PRP17 is identical to the cell division cycle CDC40 gene. cdc40 mutants arrest at the restrictive temperature after the completion of DNA replication. Although the PRP17/CDC40 gene product is essential only at elevated temperatures, splicing intermediates accumulate in prp17 mutants even at the permissive temperature. In this report we describe extensive genetic interactions between PRP17/CDC40 and the PRP8 gene. PRP8 encodes a highly conserved U5 snRNP protein required for spliceosome assembly and for both catalytic steps of the splicing reaction. We show that mutations in the PRP8 gene are able to suppress the temperature-sensitive growth phenotype and the splicing defect conferred by the absence of the Prp17 protein. In addition, these mutations are capable of suppressing certain alterations in the conserved PyAG trinucleotide at the 3' splice junction, as detected by an ACT1-CUP1 splicing reporter system. Moreover, other PRP8 alleles exhibit synthetic lethality with the absence of Prp17p and show a reduced ability to splice an intron bearing an altered 3' splice junction. On the basis of these findings, we propose a model for the mode of interaction between the Prp8 and Prp17 proteins during the second catalytic step of the splicing reaction.

Genetic and physical interactions between factors involved in both cell cycle progression and pre-mRNA splicing in Saccharomyces cerevisiae.

The PRP17/CDC40 gene of Saccharomyces cerevisiae functions in two different cellular processes: pre-mRNA splicing and cell cycle progression. The Prp17/Cdc40 protein participates in the second step of the splicing reaction and, in addition, prp17/cdc40 mutant cells held at the restrictive temperature arrest in the G2 phase of the cell cycle. Here we describe the identification of nine genes that, when mutated, show synthetic lethality with the prp17/cdc40Delta allele. Six of these encode known splicing factors: Prp8p, Slu7p, Prp16p, Prp22p, Slt11p, and U2 snRNA. The other three, SYF1, SYF2, and SYF3, represent genes also involved in cell cycle progression and in pre-mRNA splicing. Syf1p and Syf3p are highly conserved proteins containing several copies of a repeated motif, which we term RTPR. This newly defined motif is shared by proteins involved in RNA processing and represents a subfamily of the known TPR (tetratricopeptide repeat) motif. Using two-hybrid interaction screens and biochemical analysis, we show that the SYF gene products interact with each other and with four other proteins: Isy1p, Cef1p, Prp22p, and Ntc20p. We discuss the role played by these proteins in splicing and cell cycle progression.

Resistance of muscle to tumor metastases: a role for a3 adenosine receptor agonists.

Tumor metastases are extremely rare in striated muscles. Lately, we have found that muscle cell conditioned medium (MCM) inhibits the proliferation of various tumor cells while maintaining the growth of normal murine bone marrow cells. This dual activity was confirmed in vivo when the MCM was administered orally, i.e., it inhibited the development of tumor growth in mice and prevented the myelotoxic effects of chemotherapy. Adenosine was found to be one of the active components of MCM, inhibiting tumor cell growth while maintaining bone marrow cell proliferation in vitro. Adenosine is known to act as an important regulatory molecule through its binding to specific G-protein-associated A1, A(2a), A(2b) and A3 cell surface receptors. In distinction from MCM, adenosine did not suppress tumor development in mice and was not active as a chemoprotective agent when administered orally or intravenously. Thus, the in vivo activity of MCM could not be attributed to adenosine. In this study, MCM from which adenosine was enzymatically removed still retained its dual activity that was also found to be mediated through the A3 adenosine receptor (A3AR). This result led to the conclusion that natural agonists to A3AR were responsible for the activity of MCM. We further tested synthetic agonist to the A3AR and demonstrated that it possessed the same in vitro and in vivo activity profile as MCM. Taken together, muscle cells, in addition to adenosine, secrete natural agonists to A3AR. These agonists are stable nondegradable molecules and may contribute to the systemic anticancer and chemoprotective activity exerted by MCM. This group of molecules may account for the rarity of tumor metastases in muscle.

Peptides and thermoregulation.

Several peptides are now known to affect thermoregulation. These include beta-endorphin, bombesin, MIF-I, alpha-MSH, neurotensin, TRH, and DSIP. Some of these have been found to interact with the thermal effects of d-amphetamine, a drug with well established actions on thermoregulation. The effects of morphine on body temperature provide some notable comparisons with beta-endorphin, as do the similarities between the effects of naloxone and MIF-I. In general, it seems that two of the major variables which interact and modify the thermal effects of peptides are ambient temperature and route of administration.

Chronic lithium treatment and dopamine-mediated behavior.

The effect of 3--4 weeks of chronic lithium (Li) treatment in food on amphetamine-induced stereotypy, hyperactivity, and hypothermia was examined. The long-term Li treatment failed to inhibit these behaviors and even resulted in small but statistically significant potentiation of stereotypy and hypothermia. The absence of an inhibitory effect of Le on these dopaminergic processes is consistent with Li's lack of antischizophrenic properties. Previous studies reporting conflicting results, including lithium inhibition of amphetamine-induced hyperactivity, used acute or very short-term lithium administration and/or did not verify serum lithium levels to be at therapeutically equivalent levels.

Brain iron: a lesson from animal models.

Brain and blood iron deficiency (ID) can be nutritionally induced. Significant behavioral and brain-biochemical changes are observed in rats rendered iron deficient, including complete reversal of the circadian cycles of motor activity, changes in thermoregulation and stereotyped behavior, and an increased pain threshold. The increase in pain threshold is affected by diurnal factors and peripheral treatment with beta-endorphin has a significant analgesic effect, implicating selective changes in the blood-brain barrier. These effects along with modifications in responses to dopaminergic drugs, interactions of ID with neuroleptic drugs, and modifications in behavior as a result of selective brain lesions, lead to two conclusions: this animal model is appropriate for human anemia and the best explanation for the variety of behavioral and brain biochemical changes in ID rats is that the principal effect of brain ID is a selective decrease in the functional level of the dopaminergic D2 system.

Putative biological mechanisms of the effect of iron deficiency on brain biochemistry and behavior.

An animal model of nutritional iron deficiency (ID) is described that demonstrates a reduction of brain nonheme iron. The most prominent feature of ID is the significant and selective diminution of central dopamine neurotransmission resulting from the decreased number of dopamine D2 receptors in the caudate nucleus, nucleus accumbens, pituitary, and in all probability the frontal cortex. The consequences of diminished dopaminergic neurotransmission is a modification of dopamine-dependent behaviors and biochemical reactions, the most important of which is the reduction in learning processes. The role of iron in maintaining the homeostasis of normally functioning dopamine neurons and their involvement in cognitive processes cannot be excluded. An interference with iron metabolism at an early age can result in irreversible damage to developing dopamine neurons, with consequences that may manifest themselves in adult life.