PDE7 inhibitor TC3.6 ameliorates symptomatology in a model of primary progressive multiple sclerosis

BACKGROUND AND PURPOSE

cAMP plays an important role in the transduction of signalling pathways involved in neuroprotection and immune regulation. Control of the levels of this nucleotide by inhibition of cAMP-specific PDEs such as PDE7 may affect the pathological processes of neuroinflammatory diseases like multiple sclerosis (MS). In the present study, we evaluated the therapeutic potential of the selective PDE7 inhibitor, TC3.6, in a model of primary progressive multiple sclerosis (PPMS), a rare and severe variant of MS.

EXPERIMENTAL APPROACH

Theiler's murine encephalomyelitis virus-induced demyelinated disease (TMEV-IDD) is one of the models used to validate the therapeutic efficacy of new drugs in MS. As recent studies have analysed the effect of PDE7 inhibitors in the EAE model of MS, here the TMEV-IDD model was used to test their efficacy in a progressive variant of MS. Mice were subjected to two protocols of TC3.6 administration: on the pre-symptomatic phase and once the disease was established.

KEY RESULTS

Treatment with TC3.6 ameliorated the disease course and improved motor deficits of infected mice. This was associated with down-regulation of microglial activation and reduced cellular infiltrates. Decreased expression of pro-inflammatory mediators such as COX-2 and the cytokines, IL-1β, TNF-α, IFN-γ and IL-6 in the spinal cord of TMEV-infected mice was also observed after TC3.6 administration.

CONCLUSION

These findings support the importance of PDE7 inhibitors, and specifically TC3.6, as a novel class of agents with therapeutic potential for PPMS. Preclinical studies are needed to determine whether their effects translate into durable clinical benefits.

The antiproliferative action of [D-Arg(1), D-Phe(5), D-Trp(7,9), LEU(11)] substance P analogue antagonist against small-cell- and non-small-cell lung cancer cells could be due to the pharmacological profile of its tachykinin receptor antagonist

It is known that in human lung cancer samples, both small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC) cells express the neurokinin-1 (NK-1) receptor; that after binding to the NK-1 receptor the peptide substance P (SP) elicits tumour cell proliferation and an antiapoptotic effect. By contrast, it has been demonstrated that non-peptide NK-1 receptor antagonists, after binding to the NK-1 receptor and hence by blocking the SP action in SCLC/NSCLC, exert an antiproliferative action (inhibit lung cancer cell proliferation and induce the death of tumour cells by apoptosis). It is also known that SP peptide NK-1 receptor antagonists also called SP analogue antagonists (broad-spectrum GPCR antagonists, broad-spectrum neuropeptide antagonists or synthetic analogues of SP), also exert antiproliferative actions against SCLC/NSCLC. However, the underlying mechanisms involved in this antiproliferative action remain unknown. By using competition assays with SP, here we demonstrate that the antiproliferative action exerted by the [D-Arg(1), D-Phe(5), D-Trp(7,9), Leu(11)] SP analogue on human H-69 SCLC and COR-L23 NSCLC cell lines, occurs at least through the NK-1 receptor.

Phosphodiesterase 10 inhibitors: new disease modifying drugs for Parkinson's disease?

Phosphodiesterases (PDEs), as key regulators of cyclic nucleotides, and their inhibitors have been emerged as new pharmacological targets and promising drug candidates for many diseases, including central nervous system pathologies. The high level of PDE10A expression in the striatal medium spiny neurons suggests a prominent function role for the isoenzyme. Basal ganglia dysfunction is associated with neuropsychiatric disorders and until recently the development of PDE10A inhibitors has been focused on schizophrenia. Currently, the pharmaceutical research on PDE10A inhibitors is moving to show the modulation of other functions associated with the basal ganglia such the motor control. Thus, PDE10A inhibitors may be important pharmacological agents for neurodegenerative disorders such as Parkinson's and Huntington's diseases. Recent data supporting new clues for PDE10A as therapeutic target together with a concise review of the chemical structures of its inhibitors are provided here. The goal of this manuscript is to provide new ideas for assistant pharmacologist and medicinal chemists in the search for PDE10A inhibitors as new disease modifying drugs for Parkinson's disease.

Comparative assessment of PDE 4 and 7 inhibitors as therapeutic agents in experimental autoimmune encephalomyelitis

BACKGROUND AND PURPOSE

PDE4 inhibition suppresses experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). However, side effects hinder PDE4 inhibitors clinical use. PDE7 inhibition might constitute an alternative therapeutic strategy, but few data about the anti-inflammatory potential of PDE7 inhibitors are currently available. We have used the EAE model to perform a comparative evaluation of PDE4 and PDE7 inhibition as strategies for MS treatment.

EXPERIMENTAL APPROACH

Two PDE7 inhibitors, the sulfonamide derivative BRL50481 and the recently described quinazoline compound TC3.6, were assayed to modulate EAE in SJL mice, in comparison with the well-known PDE4 inhibitor Rolipram. We evaluated clinical signs, presence of inflammatory infiltrates in CNS and anti-inflammatory markers. We also analysed the effect of these inhibitors on the inflammatory profile of spleen cells in vitro.

KEY RESULTS

TC3.6 prevented EAE with efficacy similar to Rolipram, while BRL50481 had no effect on the disease. Differences between both PDE7 inhibitors are discussed. Data from Rolipram and TC3.6 showed that PDE4 and PDE7 inhibition work through both common and distinct pathways. Rolipram administration caused an increase in IL-10 and IL-27 expression which was not found after TC3.6 treatment. On the other hand, both inhibitors reduced IL-17 levels, prevented infiltration in CNS and increased the expression of the T regulator cell marker Foxp3.

CONCLUSIONS AND IMPLICATIONS

These results provide new information about the effects of Rolipram on EAE, underline PDE7 inhibition as a new therapeutic target for inflammatory diseases and show the value of TC3.6 to prevent EAE, with possible consequences for new therapeutic tools in MS.

Inhibition of endogenous phosphodiesterase 7 promotes oligodendrocyte precursor differentiation and survival

During the development of the central nervous system (CNS), oligodendrocyte precursors (OPCs) are generated in specific sites within the neural tube and then migrate to colonize the entire CNS, where they differentiate into myelin-forming oligodendrocytes. Demyelinating diseases such as multiple sclerosis (MS) are characterized by the death of these cells. The CNS reacts to demyelination and by promoting spontaneous remyelination, an effect mediated by endogenous OPCs, cells that represent approximately 5-7 % of the cells in the adult brain. Numerous factors influence oligodendrogliogenesis and oligodendrocyte differentiation, including morphogens, growth factors, chemotropic molecules, extracellular matrix proteins, and intracellular cAMP levels. Here, we show that during development and in early adulthood, OPCs in the murine cerebral cortex contain phosphodiesterase-7 (PDE7) that metabolizes cAMP. We investigated the effects of different PDE7 inhibitors (the well-known BRL-50481 and two new ones, TC3.6 and VP1.15) on OPC proliferation, survival, and differentiation. While none of the PDE7 inhibitors analyzed altered OPC proliferation, TC3.6 and VP1.15 enhanced OPC survival and differentiation, processes in which ERK intracellular signaling played a key role. PDE7 expression was also observed in OPCs isolated from adult human brains and the differentiation of these OPCs into more mature oligodendroglial phenotypes was accelerated by treatment with both new PDE7 inhibitors. These findings reveal new roles for PDE7 in regulating OPC survival and differentiation during brain development and in adulthood, and they may further our understanding of myelination and facilitate the development of therapeutic remyelination strategies for the treatment of MS.

[Attention deficit disorder and hyperactivity: a pattern of evolution?]

INTRODUCTION

When the frequency of a gene in the general population exceeds 1%, is not considered a random mutation but a mutation that has been positively selected during evolution. The high prevalence of attention deficit/hyperactivity disorder (ADHD) from 5-10% and its association with the seven-repeat allele of DRD4, which is positively selected in evolution, raising the possibility that ADHD increases the reproductive fitness of the individual and/or group. One of the main characteristics of ADHD is its diversity and is a well recognized fact that diversity confers many benefits to a population (eg. immunity).

DEVELOPMENT

This article discusses the various studies that support this hypothesis and offers further explanations on the prevalence, age distribution and sex distribution of the severity and heterogeneity of ADHD.

CONCLUSION

It is possible that the presence of altered gene combinations, as in ADHD, can bring concrete benefits to society but are detrimental to the individual.

CAPN10 alleles modify laryngeal cancer risk in the Spanish population

AIMS

Laryngeal carcinoma is a common upper respiratory tract cancer with different environmental and genetic factors involved in its development. To date, CAPN10 has been found to be extensively associated with hyperinsulinaemia and type 2 diabetes mellitus, by different groups. In addition, some reports have shown evidence that hyperinsulinaemia exerts a protective effect on laryngeal cancer risk. On the other hand, low circulating levels of IGF-1 have been recently found in patients with laryngeal carcinoma. Our objective was to examine the contribution of CAPN10 alleles to the development of laryngeal cancer.

METHODS

Cases and controls were recruited from central and southern Spain. Genotypes were determined using pyrosequencing technology. We analysed CAPN10 UCSNP-44, -43, -19, and -63 allelic distribution in 218 unrelated laryngeal cancer patients and 606 controls from the general population.

RESULTS

We found that the UCSNP-44 allele-C is significantly under-represented among patients with laryngeal cancer (OR=0.685, p=0.02).

CONCLUSION

These results indicate that some CAPN10 alleles may be exerting a protective effect on laryngeal cancer risk in the Spanish population.

Association between polymorphisms of folate-metabolizing enzymes and risk of prostate cancer

Polymorphisms of the genes 5'-10'-methylenetetrahydrofolate reductase (MTHFR, 677CT and 1298AC), methionine synthase (MTR, 2756AC) and methionine synthase reductase (MTRR, 66AC) provoke variations in enzyme activity, which can lead to alterations in the metabolism of folates and in the synthesis of S-adenosyl-methionine (SAM), the most active methyl donor in the body. This could play an important role in carcinogenesis through the degree of DNA methylation and of nucleotide synthesis. In the present study, four polymorphisms were studied, two of the methylenetetrahydrofolate reductase gene, and the other two of methionine synthase and methionine synthase reductase. Our aim was to study the association between prostate carcinoma susceptibility and these polymorphisms. A hospital-based case-control study was conducted in 182 patients (mean age: 70.7+/-7.29 years) with histologically confirmed prostate carcinoma and in 205 control subjects (mean age: 70.3+/-7.82 years) diagnosed with benign prostatic hyperplasia (BPH). Genomic DNA was extracted from peripheral leukocytes. Comparison of the MTHFR CT and TT genotypes in patients and the controls revealed significant differences (0.57 vs 0.38) (OR: 2.19, 95% CI: 1.46-3.30) and (0.06 vs 0.15) (OR: 0.36, 95% CI: 0.17-0.73), respectively. No statistically significant differences were found between patients and controls with respect to the MTHFR 1298AC, the MTR 2756AC and the MTRR 66AC polymorphisms. However, among the patients, the MTR 2756 allele C was related to a high Gleason score. We conclude that the polymorphism MTHFR C677T is clearly related to prostatic carcinogenesis, on the contrary to the other polymorphisms studied, although the MTR 2756 allele C acts as a factor of tumor aggressiveness, this being found in tumors with high carcinogenic potential.

Malignant melanomas of the nasolacrimal duct

Two patients with a history of epistaxis who were both found to have a nasolacrimal duct melanoma are presented. A literature review revealed that no previous cases of primary nasolacrimal duct melanoma have been reported. Current therapeutic modalities are discussed.

Expression of prostate specific membrane antigen (PSMA) in prostatic adenocarcinoma and prostatic intraepithelial neoplasia

The prostatic membrane antigen (PSMA) is a protein that is expressed in the prostatic epithelium. We studied the expression of PSMA in a series of 55 patients with different stages of prostate cancer and we compared the PSMA staining in prostate cancer cells, in high-grade prostatic intraepithelial neoplasia (PIN) and in histologically benign prostatic epithelium for the same specimen. For this purpose archival paraffin-embedded specimens were studied by immunohistochemistry with a monoclonal antibody 7E11-C5.3 against PSMA using the streptavidin-biotin method. The mean percentage of PSMA immunoreactivity was 56.67% in prostate cancer (CaP) cells, and 48.6% in PIN cells, which was significantly higher than benign-appearing prostatic epithelium (5.72%) (for each pair, p<0.001). PSMA expression was greater in CaP with a higher Gleason score (p=0.01), but no relationship was found with serum PSA value. We conclude that PSMA overexpression is detected in high-grade PIN and is associated with a higher Gleason score of prostate cancer. It is a potential marker for studying carcinogenesis and progression of prostate cancer.

Lifestyles, environmental and phenotypic factors associated with lip cancer: a case-control study in southern Spain

The aim of this study was to identify factors related to lip cancer (LC) considering individual characteristics and sociodemographic factors. A case-control study was carried out in the province of Granada (Andalusia, southern Spain). The cases were 105 males with squamous-cell carcinoma of the lip, diagnosed between 1987 and 1989 (aged 20-70 years) and identified by means of a population-based Cancer Registry. As controls, a randomised populational sample of 239 males, stratified by age, was used. Multiple logistic regression analysis showed that risk factors are lifetime cumulative tobacco consumption and alcohol consumption. An interaction was found between alcohol consumption and the smoking habit (leaving the cigarette on the lip): OR=23.6; 95% CI: 3.9-142.0. Other risk factors identified are clear eyes (OR=3.5; CI: 95% 1.5-8.0), sun exposure early in life and cumulative sun exposure during outdoor work (OR=11.9; 95%: CI: 1.3-108.9), and skin reaction to sun exposure (Fitzpatrick levels). Another interaction was found between skin reaction and a previous history of common sporadic warts (OR=4.4; 95% CI: 1.01-19.1). We conclude that LC is related to phenotype, skin reaction to sun exposure, cumulative and early sunlight exposure, and tobacco and alcohol consumption, as well as a low educational level. Leaving the cigarette on the lip is predictive of LC risk irrespective of cumulative tobacco consumption.