Ocular herpes: the pathophysiology,management and treatment of herpetic eye diseases

Herpesviruses are a prominent cause of human viral disease, second only to the cold and influenza viruses. Most herpesvirus infections are mild or asymptomatic. However, when the virus invades the eye, a number of pathologies can develop and its associated sequelae have become a considerable source of ocular morbidity. The most common culprits of herpetic eye disease are the herpes simplex virus (HSV), varicella zoster virus (VZV), and cytomegalovirus (CMV). While primary infection can produce ocular disease, the most destructive manifestations tend to arise from recurrent infection. These recurrent infections can wreck devastating effects and lead to irreversible vision loss accompanied by a decreased quality of life, increased healthcare usage, and significant cost burden. Unfortunately, no method currently exists to eradicate herpesviruses from the body after infection. Treatment and management of herpes-related eye conditions continue to revolve around antiviral drugs, although corticosteroids, interferons, and other newer therapies may also be appropriate depending on the disease presentation. Ultimately, the advent of effective vaccines will be crucial to preventing herpesvirus diseases altogether and cutting the incidence of ocular complications.     

Antiviral activity of Basidiomycete mycelia against influenza type A(serotype H1N1) and herpes simplex virus type 2 in cell culture

In this study, we investigated the in vitro antiviral activity of the mycelia of higher mushrooms against influenza virus type A(serotype H1N1) and herpes simplex virus type 2(HSV-2), strain BH. All 10 investigated mushroom species inhibited the reproduction of influenza virus strain A/FM/1/47(H1N1) in MDCK cells reducing the infectious titer by 2.0–6.0 lg ID50. Four species, Pleurotus ostreatus, Fomes fomentarius, Auriporia aurea, and Trametes versicolor, were also determined to be effective against HSV-2 strain BH in RK-13 cells, with similar levels of inhibition as for influenza. For some of the investigated mushroom species—Pleurotus eryngii, Lyophyllum shimeji, and Flammulina velutipes—this is the first report of an anti-influenza effect. This study also reports the first data on the medicinal properties of A. aurea, including anti-influenza and antiherpetic activities. T. versicolor 353 mycelium was found to have a high therapeutic index(324.67), and may be a promising material for the pharmaceutical industry as an anti-influenza and antiherpetic agent with low toxicity. Mycelia with antiviral activity were obtained in our investigation by bioconversion of agricultural wastes(amaranth flour after CO2 extraction), which would reduce the cost of the final product and solve some ecological problems.     

Antiviral activity of Basidiomycete mycelia against influenza type A (serotype H1N1) and herpes simplex virus type 2 in cell culture

In this study, we investigated the in vitro antiviral activity of the mycelia of higher mushrooms against influenza virus type A(serotype H1N1) and herpes simplex virus type 2(HSV-2), strain BH. All 10 investigated mushroom species inhibited the reproduction of influenza virus strain A/FM/1/47(H1N1) in MDCK cells reducing the infectious titer by 2.0–6.0 lg ID50. Four species, Pleurotus ostreatus, Fomes fomentarius, Auriporia aurea, and Trametes versicolor, were also determined to be effective against HSV-2 strain BH in RK-13 cells, with similar levels of inhibition as for influenza. For some of the investigated mushroom species—Pleurotus eryngii, Lyophyllum shimeji, and Flammulina velutipes—this is the first report of an anti-influenza effect. This study also reports the first data on the medicinal properties of A. aurea, including anti-influenza and antiherpetic activities. T. versicolor 353 mycelium was found to have a high therapeutic index(324.67), and may be a promising material for the pharmaceutical industry as an anti-influenza and antiherpetic agent with low toxicity. Mycelia with antiviral activity were obtained in our investigation by bioconversion of agricultural wastes(amaranth flour after CO2 extraction), which would reduce the cost of the final product and solve some ecological problems.     

Methyl gallate,methyl-3,4,5-trihydroxybenzoate,is a potent and highly specific inhibitor of herpes simplex virusin vitro. II. Antiviral activity of methyl gallate and its derivatives

Methyl gallate (MG), methyl-3,4,5-trihydroxybenzoate, was highly active against herpes viruses as determined by plaque reduction assay. Herper simplex virus type 2, MS strain, was sensitive to MG at a mean 50% inhibitory concentration (IC₅₀) of 0.224 g/ml in monkey kidney cells. MG was specific for herpes viruses with the relative sensitivity HSV-2>HSV-1>CMV. Two RNA viruses tested were significantly less sensitive to MG. The structural components of MG which modulate the anti-herpetic activity were identified by analysis of chemical analogues. Our structural analyses indicated that three hydroxyl groups were required but were not sufficient for the anti-herpetic action of MG. The presence and chain length of the alkyl ester were also important to the anti-herpetic activity of MG. Methyl gallate may interact with virus proteins and alter the adsorption and penetration of the virion.     

Synthesis of 1′,2′-methano-2′,3′-dideoxynucleosides as potential antivirals

The synthesis of constrained nucleosides has become an important tool to understand the SAR in the interaction between biological and synthetic nucleotides in the context of antisense oligonucleotide therapy. The incorporation of a cyclopropane into a furanose ring of a nucleoside induces some degree of constrain without affecting significantly the steric environment of a nucleoside. Here, we report a new, short and stereocontrolled synthesis of two constrained nucleosides analogues, 1′,2′- methano-2′,3′-dideoxyuridine 9, and the corresponding cytidine analog 12. X-ray crystallography revealed that the furanose ring in the constrained uridine and cytidine analogues was flattened with virtual loss of pseudorotation. The phosphoramidate esters of the novel constrained uridine and cytidine nucleosides, intended as prodrugs, were tested in cell-based assays for viral replication across the herpes virus family and HIV inhibition courtesy of Merck laboratories, Rahway. They were also tested in antiproliferative assays against colorectal and melanoma cell lines. Unfortunately, none of the compounds showed activity in these assays.     

Synthesis and anti-HSV activity of tricyclic penciclovir and hydroxybutylguanine derivatives

A series of tricyclic penciclovir (PCV) and hydroxybutylguanine (HBG) derivatives have been prepared with enhanced lipophilicity following an efficient synthetic route. All the novel tricyclic derivatives were evaluated for inhibitory activity against herpes simplex virus 1 and 2 (HSV-1, HSV-2) and thymidine kinase deficient (ACV resistant) HSV-1. The tricyclic HBG derivatives were devoid of inhibitory activity however several of the tricyclic PCV derivatives showed promising antiviral activity, in particular 9g (R?=?4-MeO-C₆H₄) displayed good inhibitory activity (HSV-1 EC₅₀ 1.5?μM, HSV-2 EC₅₀ 0.8?μM) and retained inhibitory activity in HSV-1 TK^? cells (EC₅₀ 0.8?μM). Computational docking experiments supported the biological data observed and this preliminary study provides useful data for further development of tricyclic acyclic nucleoside derivatives with improved lipophilicity and retention of activity in HSV-1 TK deficient strains. Also, the new tricyclic derivatives were evaluated against a broad range of other DNA and RNA viruses, but were found to be inactive at subtoxic concentrations. In addition, weak to moderate cytostatic effect was observed for the new compounds.     

Chemical interactions with herpes simplex type 2 virus: Enhancement of transformation by hydrazine and 1,2-dimethylhydrazine

Quantitative assays for the morphological transformation of 3T3 Swiss mouse cells by herpes simplex type 2 virus (HSV-2) were employed to examine the effect on cell transformation of chemical carcinogens and suspected carcinogens. Exposure of the cells to the chemical compound, followed by virus infection, resulted in enhancement of transformation when compared to that observed with chemical or virus alone. Enhancement occurred in tests utilizing either UV light-inactivated HSV-2 (strain 333) or a temperature-sensitive (ts) mutant of HSV-2 [A₈(293)]. A series of seven ts-mutants were tested and exhibited varying degrees of transformation. Enhancement of transformation occurred in cells treated with hydrazine (HZ) and 1,2-dimethylhydrazine (SDMH). No enhancement occurred when cells were treated with monomethylhydrazine, 1,1-dimethylhydrazine and the jet fuels JP-5, JP-10, RJ-4 and RJ-5. A strong time dependence after treatment was demonstrated with some enhancement seen at 6 h after chemical treatment but the greatest enhancement appeared when virus infection began after 24 h of chemical exposure.     

Inhibition of herpes simplex virus type 1 entry by chloride channel inhibitors tamoxifen and NPPB

Herpes simplex virus type 1 (HSV-1) infection is very common worldwide and can cause significant health problems from periodic skin and corneal lesions to encephalitis. Appearance of drug-resistant viruses in clinical therapy has made exploring novel antiviral agents emergent. Here we show that chloride channel inhibitors, including tamoxifen and 5-nitro-2-(3-phenyl-propylamino) benzoic acid (NPPB), exhibited extensive antiviral activities toward HSV-1 and ACV-resistant HSV viruses. HSV-1 infection induced chloride ion influx while treatment with inhibitors reduced the increase of intracellular chloride ion concentration. Pretreatment or treatment of inhibitors at different time points during HSV-1 infection all suppressed viral RNA synthesis, protein expression and virus production. More detailed studies demonstrated that tamoxifen and NPPB acted as potent inhibitors of HSV-1 early entry step by preventing viral binding, penetration and nuclear translocation. Specifically the compounds appeared to affect viral fusion process by inhibiting virus binding to lipid rafts and interrupting calcium homeostasis. Taken together, the observation that tamoxifen and NPPB can block viral entry suggests a stronger potential for these compounds as well as other ion channel inhibitors in antiviral therapy against HSV-1, especially the compound tamoxifen is an immediately actionable drug that can be reused for treatment of HSV-1 infections.     

The role of macroautophagy in the ageing process, anti-ageing intervention and age-associated diseases

Macroautophagy is a degradation/recycling system ubiquitous in eukariotic cells, which generates nutrients during fasting under the control of amino acids and hormones, and contributes to the turnover and rejuvenation of cellular components (long-lived proteins, cytomembranes and organelles). Tight coupling between these two functions may be the weak point in cell housekeeping. Ageing denotes a post-maturational deterioration of tissues and organs with the passage of time, due to the progressive accumulation of the misfunctioning cell components because of oxidative damage and an age-dependent decline of turnover rate and housekeeping. Caloric restriction (CR) and lower insulin levels may slow down many age-dependent processes and extend lifespan. Recent evidence is reviewed showing that autophagy is involved in ageing and in the anti-ageing action of anti-ageing calorie restriction: function of autophagy declines during adulthood and is almost negligible at older age; CR prevents the age-dependent decline of autophagic proteolysis and improves the sensitivity of liver cells to stimulation of lysosomal degradation; protection of autophagic proteolysis from the age-related decline co-varies with the duration and level of anti-ageing food restriction like the effects of CR extending lifespan; the pharmacological stimulation of macroautophagy has anti-ageing effects. Besides the involvement in ageing, macroautophagy may have an essential role in the pathogenesis of many age-associated diseases. Higher protein turnover may not fully account for the anti-ageing effects of macroautophagy, and effects of macroautophagy on housekeeping of the cell organelles, antioxidant machinery of cell membranes and transmembrane cell signaling should also be considered.     

Synthesis and characterization of a C6 nucleoside analogue for the in vivo imaging of the gene expression of herpes simplex virus type-1 thymidine kinase (HSV1 TK)

The synthesis and biological evaluation of '6-(1,3-dihydroxyisobutyl)thymine' (DHBT; 1), which corresponds to 6-[3-hydroxy-2-(hydroxymethyl)propyl]-5-methylpyrimidine-2,4(1H,3H)-dione, is reported. DHBT (1) was designed as a new substrate for herpes simplex virus type-1 thymidine kinase (HSV1 TK). The compound was found to be exclusively phosphorylated by HSV1 TK, and to exhibit good binding affinity (Ki = 35.3+/-1.3 microM). Cell-proliferation assays with HSV1-TK-transduced human osteosarcoma cells (143B-TK+-HSV1-WT) and with both human-thymidine-kinase-1-negative (143B-TK-) and non-transduced parental (MG-63) cells indicate that 1 is less cytotoxic than the standard drug Ganciclovir. Thus, DHBT (1) represents a promising precursor of a nontoxic reporter probe for the monitoring of HSV1 TK gene expression by means of positron-emission tomography (PET).     

Serum C‐reactive protein in the prediction of cardiovascular diseases: Overview of the latest clinical studies and public health practice

Cardiovascular disease is the most common cause of morbidity and mortality globally. Epidemiological studies using high‐sensitivity assays for serum C‐reactive protein have shown a consistent association between cardiovascular disease risk and serum C‐reactive protein concentrations. C‐reactive protein is a biomarker for inflammation, and has been established in clinical practice as an independent risk factor for cardiovascular disease events. There is evidence that serum C‐reactive protein is an excellent biomarker of cardiovascular disease and is also an independent and strong predictor of adverse cardiovascular events. Further characterization of the impact and influence of lifestyle exposures and genetic variation on the C‐reactive protein response to cardiovascular disease events may have implications for the therapeutic approaches to reduce cardiovascular disease events. This review summarizes the studies that have examined the association between serum C‐reactive protein and the risk of cardiovascular disease. We also discuss the impact of independent factors and C‐reactive protein genetic polymorphisms on baseline plasma C‐reactive protein levels.     

Phosphorylation of dGMP analogs by vaccinia virus TMP kinase and human GMP kinase

Vaccinia virus thymidylate kinase, although similar in sequence to human TMP kinase, has broader substrate specificity and phosphorylates (E)-5-(2-bromovinyl)-dUMP and dGMP. Modified guanines such as glyoxal-dG, 8-oxo-dG, O⁶-methyl-dG, N²-ethyl-dG and N⁷-methyl-dG were found present in cancer cell DNA. Alkylated and oxidized dGMP analogs were examined as potential substrates for vaccinia TMP kinase and also for human TMP and GMP kinases. Molecular models obtained from structure-based docking rationalized the enzymatic data. All tested nucleotides are found surprisingly substrates of vaccinia TMP kinase and also of human GMP kinase. Interestingly, O⁶-methyl-dGMP is the only analog specific for the vaccinia enzyme. Thus, O⁶-Me-dGMP could be useful for designing new compounds of medical interest either in antipoxvirus therapy or in experimental combined gene/chemotherapy of cancer. These results also provide new insights regarding dGMP analog reaction with human GMP kinase and their slow recycling by salvage pathway nucleotide kinases.     

Tricalcium phosphate nanoparticles enable rapid purification, increase transduction kinetics, and modify the tropism of mammalian viruses

Adenoviral, adeno-associated viral, and retroviral particles are chosen as gene delivery shuttles in more than 50% of all gene therapy clinical trials. Bulk availability of clinical-grade viral particles and their efficiency to transduce the therapeutic cargo into specific target cells remain the most critical bottlenecks in gene therapy applications to date. Capitalizing on the flame-spray technology for the reproducible economic large-scale production of amorphous tricalcium phosphate nanoparticulate powders (ATCP), we designed a scalable ready-to-use gravity-flow column set-up for the straightforward concentration and purification of transgenic adenoviral, adeno-associated viral, and lentiviral particles. Specific elution buffers enabled rapid release of viral particles from the ATCP matrix of the column and provided high-titer virus preparations in an unsurpassed period of time. The interaction of ATCP with adenoviral, adeno-associated viral, and lentiviral particles in solution increased the transduction kinetics of several mammalian cell lines in culture. The nanoparticles were also able to modify the tropism of murine leukemia virus (MLV) towards transduction of human cells. Based on these findings, we believe that the use of flame-spray tricalcium phosphate nanoparticles will lead to important progress in the development of future gene therapy initiatives.     

The eye of the freshwater prosobranch gastropod Viviparus viviparus: ultrastructure, electrophysiology and behaviour

We used light and electron microscopy to study the retinal organization of the eye of Viviparus viviparus. Electroretinogram (ERG) recordings were used to investigate the electrophysiological responsiveness to flashes of light of varying intensity and colour, behavioural observations were made of phototactic reactions, and optical measurements and calculations related to the path of light rays in the eye were made. The retina contains principally two types of cells: first, photoreceptor cells with both microvilli and cilia, and second, cells, often strongly pigmented, that are supportive in nature. The ERGs obtained were essentially similar in form, amplitude and duration to those known from other gastropods that have exclusively rhabdomeric photoreceptors. Spectral sensitivity curves closely fitted the absorption spectrum of a rhodopsin‐like pigment. The spectral sensitivity peak was at 475 nm. Measurements of the refractive indices of the lens gave values of 1.55 for the outer layer and 1.57 for the lens core. None of the snails tested exhibited a ‘defensive reflex’ and although no preference between light and dark regions was expressed, we nevertheless argue that, on the basis of optical measurements and calculations, the eye of V. viviparus is well‐adapted for seeing under water. Our main conclusion is that in the eye of V. viviparus with its ‘mixed photoreceptor’ cell type, there is an equal probability for microvilli and cilia to function as principal photoreceptive elements.     

Therapeutic potential of RAS prenylation pharmacological inhibitors in the treatment of breast cancer,recent progress,and prospective

Breast cancer is one of the most prevalent malignancies among women around the world. RAS proteins require posttranslational modifications, including protein prenylation for proper membrane localization and signaling. Regulation of RAS signaling via specific and novel pharmacological inhibitors is a potentially novel therapeutic approach in breast cancer therapy. This review summarizes the recent knowledge about the clinical value of RAS prenylation pharmacological inhibitors in breast cancer treatment.