Effect of Helichrysum italicum in Promoting Collagen Deposition and Skin Regeneration in a New Dynamic Model of Skin Wound Healing

Natural products have many healing effects on the skin with minimal or no adverse effects. In this study, we analyzed the regenerative properties of a waste product (hydrolate) derived from Helichrysum italicum (HH) on scratch-tested skin cell populations seeded on a fluidic culture system. Helichrysum italicum has always been recognized in the traditional medicine of Mediterranean countries for its wide pharmacological activities. We recreated skin physiology with a bioreactor that mimics skin stem cell (SSCs) and fibroblast (HFF1) communication as in vivo skin layers. Dynamic culture models represent an essential instrument for recreating and preserving the complex multicellular organization and interactions of the cellular microenvironment. Both cell types were exposed to two different concentrations of HH after the scratch assay and were compared to untreated control cells. Collagen is the constituent of many wound care products that act directly on the damaged wound environment. We analyzed the role played by HH in stimulating collagen production during tissue repair, both in static and dynamic culture conditions, by a confocal microscopic analysis. In addition, we performed a gene expression analysis that revealed the activation of a molecular program of stemness in treated skin stem cells. Altogether, our results indicate a future translational application of this natural extract to support skin regeneration and define a new protocol to recreate a dynamic process of healing.

Electrospun Nanofibers Encapsulated with Natural Products: A Novel Strategy to Counteract Skin Aging

The skin is the primary tissue affected by wounds and aging, significantly impacting its protective function. Natural products are widely used in cosmetics, representing a new approach to preventing age-related damage. Nanomedicine combines nanotechnology and traditional treatments to create innovative drugs. The main targets of nanotechnological approaches are wound healing, regeneration, and rejuvenation of skin tissue. The skin barrier is not easily permeable, and the creation of modern nanodevices is a way to improve the passive penetration of substances. In this study, Helichrysum italicum oil (HO) was combined with different types of electrospun nanofibers to study their protective activity on the skin and to evaluate their future application for topical treatments. In the present research, we used biodegradable polymers, including polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP), which were characterized by a scanning electron microscope (SEM). All results show a positive trend in cell proliferation and viability of human skin stem cells (SSCs) and BJ fibroblasts pre-treated with combined nanofibers and then exposed to UV stress. Gene expression analysis revealed the activation of a molecular rejuvenation program in SSCs treated with functionalized nanofibers before UV exposure. Understanding the mechanisms involved in skin changes during aging allows for the future application of nanomaterials combined with HO directly to the patients.

Hydrolat of Helichrysum italicum promotes tissue regeneration during wound healing

Wound healing is a dynamic process involving different cell types with distinct roles according to the stages of healing. Fibroblasts and stem cells actively participate in tissue regeneration. A proper stimulation could contribute to enhance wound healing process-es. Helichrysum italicum (H. italicum) is a medical plant well described for its pharmacological, antimicrobial, and anti-inflammatory activities. Aim of the present work was to examine the effect of the hydrolat derivate from H. italicum on stem cells isolated from skin and fibroblasts in vitro in presence or absence of tissue damage. The viability and proliferation of all cell types cultured in dif-ferent conditions were analyzed by MTT and BrdU assays. Cell proliferation after wound was analyzed with scratch test. Also, the expression of the main genes involved in tissue repair was evaluated by RT-qPCR analysis. Here we describe the capability of hy-drolat of H. italicum to promote tissue regeneration after scratch test both in stem cells and in fibroblasts. Moreover, the gene ex-pression analysis revealed that, hydrolat of H. italicum is also able to enhance stemness related. In conclusion our results are en-couraging, highlighting novel regenerative properties of hydrolat of H. italicum and paving the way for future application of this wasting product in accelerating wound healing.

Characterization of the Electrophysiological Characteristics of Chronic Atrial Fibrillation for Efficient Simulations

Atrial biophysical simulations have the potential to enhance outcomes by enabling the simulation of pharmacological and ablative strategies. However, the high computational times associated with such simulations render them unsuitable for diagnostic purposes. To address this challenge, discrete models such as cellular automata (CA) have been developed, which consider a finite number of states, thus significantly reducing computational times. Yet, there is a pressing need to determine whether CA can replicate pathological simulations with accuracy. The analysis of simulations under different degrees of electrical remodeling shows an expected increase of Action Potential Duration (APD) with the previous Diastolic Interval (DI) interval, indicating short-term memory of atrial cardiomyocytes: shorter APD0 provoked shorter APD+1, and previous DI has a similar effect on APD+1. Independent prediction using both APD0 and DI was found to provide a far better estimation of APD+1 values, compared to relying on DI alone (p<<0.01). Finally, the CA models were able to replicate reentrant patterns and cycle lengths of different states of atrial remodeling with a high degree of accuracy when compared to biophysical simulations. Overall, the use of atrial CA with short-term memory allows accurate reproduction of arrhythmic behavior in pathological tissue within a clinically relevant timeframe.Clinical Relevance- Discrete electrophysiological models simulate pathological self-sustained arrhythmias in diagnostic times.

Assessment of Risk for Ventricular Tachycardia based on Extensive Electrophysiology Simulations

Patients that have suffered a myocardial infarction are at high risk of developing ventricular tachycardia. Patient stratification is often determined by characterization of the underlying myocardial substrate by cardiac imaging methods. In this study, we show that computer modeling of cardiac electrophysiology based on personalized fast 3D simulations can help to assess patient risk to arrhythmia. We perform a large simulation study on 21 patient digital twins and reproduce successfully the clinical outcomes. In addition, we provide the sites which are prone to sustain ventricular tachycardias, i.e, onset sites around the scar region, and validate if they colocalize with exit sites from slow conduction channels.Clinical relevance- Fast electrophysiological simulations can provide advanced patient stratification indices and predict arrhythmic susceptibility to suffer from ventricular tachycardia in patients that have suffered a myocardial infarction.

Smart Nanofibers with Natural Extracts Prevent Senescence Patterning in a Dynamic Cell Culture Model of Human Skin

Natural cosmetic products have recently re-emerged as a novel tool able to counteract skin aging and skin related damages. In addition, recently achieved progress in nanomedicine opens a novel approach yielding from combination of modern nanotechnology with traditional treatment for innovative pharmacotherapeutics. In the present study, we investigated the antiaging effect of a pretreatment with Myrtus communis natural extract combined with a polycaprolactone nanofibrous scaffold (NanoPCL-M) on skin cell populations exposed to UV. We set up a novel model of skin on a bioreactor mimicking a crosstalk between keratinocytes, stem cells and fibroblasts, as in skin. Beta-galactosidase assay, indicating the amount of senescent cells, and viability assay, revealed that fibroblasts and stem cells pretreated with NanoPCL-M and then exposed to UV are superimposable to control cells, untreated and unexposed to UV damage. On the other hand, cells only exposed to UV stress, without NanoPCL-M pretreatment, exhibited a significantly higher yield of senescent elements. Keratinocyte-based 3D structures appeared disjointed after UV-stress, as compared to NanoPCL-M pretreated samples. Gene expression analysis performed on different senescence associated genes, revealed the activation of a molecular program of rejuvenation in stem cells pretreated with NanoPCL-M and then exposed to UV. Altogether, our results highlight a future translational application of NanoPCL-M to prevent skin aging.

Combination of phenotype and polygenic risk score in breast cancer risk evaluation in the Spanish population: a case -control study

Background

In recent years, the identification of genetic and phenotypic biomarkers of cancer for prevention, early diagnosis and patient stratification has been a main objective of research in the field. Different multivariable models that use biomarkers have been proposed for the evaluation of individual risk of developing breast cancer.

Methods

This is a case control study based on a population-based cohort. We describe and evaluate a multivariable model that incorporates 92 Single-nucleotide polymorphisms (SNPs) (Supplementary Table S1) and five different phenotypic variables and which was employed in a Spanish population of 642 healthy women and 455 breast cancer patients.

Results

Our model allowed us to stratify two groups: high and low risk of developing breast cancer. The 9th decile included 1% of controls vs 9% of cases, with an odds ratio (OR) of 12.9 and a p-value of 3.43E-07. The first decile presented an inverse proportion: 1% of cases and 9% of controls, with an OR of 0.097 and a p-value of 1.86E-08.

Conclusions

These results indicate the capacity of our multivariable model to stratify women according to their risk of developing breast cancer. The major limitation of our analysis is the small cohort size. However, despite the limitations, the results of our analysis provide proof of concept in a poorly studied population, and opens up the possibility of using this method in the routine screening of the Spanish population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-020-07584-9.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-020-07584-9.

Association of Reduced Factor VIII with Impaired Platelet Reactivity to Adrenalin and Collagen after Total Thyroidectomy

Twenty-one thyroprival patients, previously submitted to total thyroidectomy for tumours, were investigated during stabilized L-thyroxine supplementation and at the end of a 20-25 day “no-therapy” period, necessary for a 131I total body scintigraphy. During supplementation therapy a lower than normal mean betathromboglobulin (beta-TG) release level was found, the other blood clotting and platelet function tests being normal. After substitution therapy withdrawal, platelet function tests showed reduced adrenalin aggregation, increased collagen threshold aggregating concentrations, decreased beta-TG release values and reduced aggregation to ristocetin, whereas blood clotting tests showed prolonged aPTT values and reduced levels of factor VIII: C and vWf: Ag. We conclude that in acquired hypothyroidism the lowering of factor VIII: C and vWf: Ag (acquired von Wille brand disease) is associated with impaired platelet reactivity not only to ristocetin but also to collagen and especially adrenalin. In the patients investigated these changes were almost completely corrected by substitutive therapy with L-thyroxine at clinically effective doses.

The Maximum Capture Problem with Uncertainty

The strategic location of servers by a firm in a competitive environment is basic in the determination or division of market shares. Let us suppose that a firm wants to locate p servers so as to maximize market capture in a region where competitors are already located but where there is uncertainty—there are several possible future scenarios with respect to demand and/or the location of competitors. The firm will want a strategy of positioning that will do as ‘well as possible’ over the future scenarios. In this paper we will present a discrete location model formulation to address this maximum capture problem with uncertainty.

FTY720 Pharmacokinetics in Mild to Moderate Hepatic Impairment

The influence of mild and moderate hepatic impairment on FTY720 pharmacokinetics was assessed. The authors enrolled 32 subjects consisting of 8 with mild and 8 with moderate hepatic impairment based on Child-Pugh criteria and 16 demographically matched control subjects. A single 1-mg oral dose of FTY720 was administered under fasting conditions. Blood, plasma, and urine samples were obtained over a 14-day period for measurement of FTY720 and metabolite concentrations and protein binding. Total blood lymphocyte counts and heart rate were serially monitored to assess pharmacologic responses to FTY720. Peak FTY720 blood concentrations were similar across groups. Oral clearance (CL/F) was reduced 10% in mild hepatic impairment (P = .493) and 31% in moderate hepatic impairment (P = .034). There were no significant differences in blood exposure to the hexanoic or butanoic acid metabolites among groups. The effect of FTY720 on blood lymphocytes was similar across groups, with a mean decrease of 44% from the predose value. Like-wise, the effect of FTY720 on supine heart rate was similar across groups, with a mean 13% decrease from the predose rate occurring 2 to 4 hours postdose and recovering within 1 to 2 days. Although hepatic impairment elicited changes in the disposition of FTY720, the magnitude of these changes suggests that the FTY720 dose does not need to be adjusted in mild or moderate hepatic-impaired patients.

Thorough QT study of the effects of vildagliptin, a dipeptidyl peptidase IV inhibitor, on cardiac repolarization and conduction in healthy volunteers

OBJECTIVE

This randomized, double-blind study evaluated the effects of vildagliptin, a dipeptidyl peptidase IV inhibitor for treating type 2 diabetes, on cardiac repolarization and conduction.

METHODS

Healthy volunteers (n = 101) were randomized (1:1:1:1 ratio) to vildagliptin 100 or 400 mg, moxifloxacin 400 mg (active control), or placebo once daily for 5 days. Electrocardiograms were recorded at baseline and day 5 for 24 hours post-dose. Placebo-adjusted mean change from baseline in QT interval, heart-rate-corrected QT intervals by Fridericia's (QTcF) or Bazett's (QTcB) formula, and PR and QRS intervals were compared at each time-point (time-matched analysis) and for values averaged across the dosing period (time-averaged analysis).

RESULTS

For time-matched analysis, mean changes in QTcF with vildagliptin were below predefined limits for QTc prolongation (mean increase <5 ms; upper 90% confidence interval [CI] < 10 ms), except for vildagliptin 100 mg at 1 and 8 hours post-dose (upper 90% CI > 10 ms). With moxifloxacin, significant QTcF prolongation occurred at most time-points, demonstrating assay sensitivity. No vildagliptin- or placebo-treated volunteer had QTcF > 450 ms. Incidences of QTcF increases ≥30 ms with vildagliptin (100 and 400 mg) and placebo were similar (4-8%) and were much lower than with moxifloxacin (39%). No QTcF increase ≥60 ms was observed with vildagliptin or placebo (versus one with moxifloxacin). Time-averaged, time-matched, and categorical analyses of QT/QTcF/QTcB showed similar results. Drug exposure analysis showed no correlation between vildagliptin plasma levels and QTc changes. Vildagliptin had no effect on PR or QRS intervals. Although this study, completed before publication of current ICH E14 guidelines, was underpowered for time-matched analysis, the results are consistent with lack of effect of vildagliptin on QTc.

CONCLUSION

Vildagliptin did not prolong QT interval or affect cardiac conduction at the highest daily therapeutic dose or a fourfold higher dose.

Pustular psoriasis and drug-induced pustulosis

We report the case of a 65-year-old female patient that has suffered several flares of exanthematous pustulosis, some of them attributable to pustular psoriasis and others that were drug-induced, resembling acute generalized exanthematous pustulosis. In particular, we describe two severe flares that were induced by ciprofloxacin. Patch tests yielded positive results to ciprofloxacin and to other quinolones and reproduced the original lesional pattern both clinically and histologically. We discuss the diagnostic challenge that exanthematous pustulosis represents and the value of patch testing in this setting, as a helpful tool to assess drug participation in these eruptions.

Incidence and factors associated with recurrence after incomplete excision of basal cell carcinomas: a study of 90 cases

BACKGROUND

Management of incompletely excised basal cell carcinomas (BCC) remains controversial.

OBJECTIVE

The aim of this study was to assess the rate and the factors associated with the recurrence of incompletely excised BCC.

METHODS

In this retrospective monocentric study, data from all surgically excised BCC during 4 years (2000 to 2003) were analysed.

RESULTS

A total of 947 BCC were excised. Of these, 90 were incompletely excised (9.5%). This group was kept under clinical follow-up for a median period of 62.5 months (range 12-84). Recurrence was confirmed in 29 patients (32.2%). The median interval to recurrence was 12 months (range 1-57). Recurrence of incompletely excised BCC was significantly higher (P < 0.05) in younger patients, in aggressive histological types and in localizations like postauricular and nasogenian folds.

CONCLUSION

Observation might be an acceptable option in many situations, but for patients with aggressive types of BCC, or with tumours localized in risk areas of the face, immediate re-excision appears to be the treatment of choice. A careful follow-up is indicated for at least 3 years; however, long lasted recurrence should not be underestimated.

Linear psoriasis - a case report

A 56-year-old woman presented with a 3-month history of erythematous plaques covered by scales and limited to the right side of her body. The plaques were arranged along Blaschko's lines with a marked mid-line cutoff. The histopathologic analysis of a skin biopsy in conjunction with the anamnesis allowed the diagnosis of linear psoriasis. Our patient showed a good clinical response to antipsoriatic treatment.

[A cutaneous thickening case...]

The authors present a clinical case of a 79 years old female patient, with a progressive cutaneous thickening of the face, trunk and limbs, lasting for 6 years. She also presented exertional dyspnea and intermittent solid dysphagia. The laboratory study identified IgG KAPA monoclonal protein and antinuclear antibodies with a speckled pattern. The nailfold capillaroscopy was normal. A detailed physical examination together with cutaneous histopathology led to the diagnosis of Scleromyxedema, a rare cutaneous scleroderma like disease. The differential diagnosis of cutaneous sclerosis is discussed.

Outcomes of Guided Imagery (GI) in Patients Receiving Radiation Therapy for Breast Cancer

Background: There is an emerging recognition of the importance of Integrative Medicine in cancer care. We initiated a study evaluating the impact of GI on patients undergoing radiation therapy for breast cancer.Materials and Methods: A prospective, IRB-approved study evaluating the efficacy of GI among patients receiving radiation therapy for breast cancer was completed. Eligible patients had GI sessions with an Integrative Oncology Nurse (ION) and were given the tools and were trained techniques for self practice. The study endpoints include evaluating relaxation response to GI sessions using clinical variables that represent the level of an individuals stress and anxiety. These biofeedback measures included blood pressure (BP), respiration rate (RR), pulse rate (PR), and skin temperature (temp.) before and after the GI exercise. Further, the EQ-5D questionnaire, an established and validated tool for measuring health outcomes, was used for the subjective assessment. Patients completed the EQ-5D questionnaire prior to their first GI session (baseline data) and again at completion of radiation treatment. Patient feedback on their overall experience was collected at the end of the planned RT treatment through a satisfaction survey.Results: In all, 68 breast cancer patients have completed the protocol. The median age is 57 years. Median number of GI sessions with the ION was 4 (range: 1-6). In all cases, the parameters measured statistically significant improvement from baseline; median RR decreased from 19.6 per minute to 17.5 per minute; the mean drop of 4 beats/ minute in the pulse rate was observed. The mean drop in the systolic BP was 8.6mmHg, and the mean drop in the diastolic BP was 3.6 mmHg, and the mean skin temperature increased from 84.70F to 89.40F indicating increase in peripheral capillary flow secondary to a decrease in the sympathetic response. Results are summarized in Table 1. Overall 86% described the GI sessions as helpful, and 100% would recommend this intervention to others.Clinical VariablePrior to GI session (mean values)After GI session (mean values)p-valueRespiration rate19.617.5&lt;0.001Pulse rate77.073.00.002Diastolic BP71.668.00.02Systolic BP124.3115.7&lt;0.001Skin temp.84.7°F89.4°F0.007 Conclusion: The results of this study illustrate the positive impact of GI as measured through subjective and objective parameters. In improving the overall care of breast cancer patients there may be value to incorporating practices of Integrative Medicine.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5039.

Characterization of Bordetella pertussis growing as biofilm by chemical analysis and FT-IR spectroscopy

Although Bordetella pertussis, the etiologic agent of whooping cough, adheres and grows on the ciliated epithelium of the respiratory tract, it has been extensively studied only in liquid cultures. In this work, the phenotypic expression of B. pertussis in biofilm growth is described as a first approximation of events that may occur in the colonization of the host. The biofilm developed on polypropylene beads was monitored by chemical methods and Fourier transform infrared (FT-IR) spectroscopy. Analysis of cell envelopes revealed minimal differences in outer membrane protein (OMP) pattern and no variation of lipopolysaccharide (LPS) expression in biofilm compared with planktonically grown cells. Sessile cells exhibited a 2.4- to 3.0-fold higher carbohydrate/protein ratio compared with different types of planktonic cells. A 1.8-fold increased polysaccharide content with significantly increased hydrophilic characteristics was observed. FT-IR spectra of the biofilm cells showed higher intensity in the absorption bands assigned to polysaccharides (1,200-900 cm(-1) region) and vibrational modes of carboxylate groups (1,627, 1,405, and 1,373 cm(-1)) compared with the spectra of planktonic cells. In the biofilm matrix, uronic-acid-containing polysaccharides, proteins, and LPS were detected. The production of extracellular carbohydrates during biofilm growth was not associated with changes in the specific growth rate, growth phase, or oxygen limitation. It could represent an additional virulence factor that may help B. pertussis to evade host defenses.

Recombinant adenovirus vectors activate the alternative complement pathway, leading to the binding of human complement protein C3 independent of anti-ad antibodies

Recombinant adenoviruses are one of the most common gene transfer vectors utilized in human clinical trials, but it is also clear that systemic administration of this virus will be met by host innate and adaptive antiviral immune responses. One element of innate immunity is the complement system, a group of proteins that has evolved to rapidly recognize foreign microbes and viruses and to clear them from the circulatory system prior to their gaining entry to vulnerable host cells. Excessive complement activation can initiate or propagate a number of deleterious inflammatory responses, by release of potent cytokines and anaphylatoxins and/or by direct cellular toxicity. These reactions can progress rapidly and are factors important in serious complications, including the systemic inflammatory response syndrome and the adult respiratory distress syndrome.

Improved efficacy of gene therapy approaches for Pompe disease using a new, immune-deficient GSD-II mouse model

Glycogen storage disease type II (GSD-II) is a lysosomal storage disorder in which the lack of human acid-alpha glucosidase (hGAA) activity results in massive accumulations of glycogen in cardiac and skeletal muscle fibers. Affected individuals die of cardiorespiratory failure secondary to the skeletal and/or cardiac muscle involvement. Recombinant hGAA enzyme replacement therapy (ERT) is currently in clinical trials and, although promising, ERT may be limited by large-scale production issues and/or the need for frequent infusions. These limitations could be circumvented or augmented by gene therapy strategies. Previous findings in our lab demonstrated that hepatic targeting of a modified adenovirus vector expressing human GAA was able to correct the glycogen accumulation in multiple affected muscles in the GAA-KO mice, by virtue of high-level, hepatic secretion of hGAA. However, although the vector persisted and expressed hGAA for 6 months in the liver, plasma hGAA was not detectable beyond 10 dpi (days postinjection), and reaccumulation of glycogen was observed. Two possibilities may have contributed to this phenomenon, the shut down of the CMV promoter and/or the onset of high levels of anti-hGAA antibodies. In order to test these and other possibilities, we have now developed an immune-deficient mouse model of GSD-II by interbreeding GAA-KO mice with severe combined immune-deficient (SCID) mice, generating double knockout, GAA-KO/SCID mice. In this new mouse model, we evaluated the efficacy of an [E1-, polymerase-] AdhGAA vector, in the absence of anti-hGAA antibody responses. After intravenous injection, GAA detection in the plasma was prolonged for at least 6 months secondary to the lack of anti-hGAA antibody production in all of the treated mice. GAA-KO/SCID mice treated with high doses of viral vector demonstrated longer durations of glycogen correction in both skeletal and cardiac muscles, relative to mice injected with lower doses of the vector. Notably, within 2 weeks of vector injection, muscle strength and coordination was normalized, and the improved muscle function persisted for at least 6 months. In summary, this new mouse model of GSD-II now makes it possible to assess the full potential for efficacy of any GAA-expressing vector (and/or ERT) contemplated for use in GSD-II gene therapy, without the negative influence that anti-hGAA antibodies entail.

Liver toxicities typically induced by first-generation adenoviral vectors can be reduced by use of E1, E2b-deleted adenoviral vectors

Adenoviral vectors from which the E1 region has been deleted ([E1(-)] Ad) are known to induce strong immune responses after systemic delivery. In this study we have evaluated liver toxicities in mice after intravenous injection with high doses of [E1(-)] or modified [E1(-), E2b(-)] Ad vectors (both expressing the bacterial beta-galactosidase [lacZ] marker gene) in C57BL/6, BALB/c, and SCID mice. Our data demonstrate a marked reduction in maximal liver toxicities and pathologies (typically noted at 21 days postinjection) with the use of the [E1(-), E2b(-)] modified vector in all strains of mice tested. Our data also demonstrated that despite the use of the [E1(-), E2b(-)] Ad vector, significant liver toxicities were still observed. To address this issue and the fact that the lacZ gene was perceived as a foreign antigen in the immune-competent C57BL/6 and BALB/c mice, we similarly injected mice tolerant of LacZ (lacZ-TG). In contrast to our studies in C57BL/6 and BALB/c mice, LacZ-TG mice exhibited virtually no evidence of hepatotoxicity after intravenous injection with the [E1(-), E2b(-)] vector, in contrast to use of the [E1(-)] Ad vector. Our results demonstrate that the [E1(-), E2b(-)] Ad vector class can reduce liver toxicities typically ascribed to Ad vector-mediated gene transfer after transfer of a highly immunogenic or foreign gene, whereas transfer of a transgene that is perceived as nonforeign by the host can be delivered with virtually no evidence of toxicity. On the basis of a careful review of the literature, these improvements in vector safety rival those noted with other, more significantly modified Ad vectors described to date.

Determination of phenol and o-cresol by GC/MS in a fatal poisoning case

A fatality due to the ingestion of solution containing phenol and o-cresol is described. The pathological findings were typical of acute substantial poisoning. Blood, urine and stomach content were obtained during post mortem examinations. Phenol and o-cresol were identified using GC/MS. The extractions from autopsy materials were obtained as follows: by gel permeation with cyclohexane/dichloromethane from stomach content, by solid phase extraction (SPE) from urine and by deproteinization with acetonitrile from blood. The phenol and o-cresol concentrations in the samples were found, respectively, as follows: 115.0 and 5.0 microg/g in the stomach contents, 58.3 and 1.9 microg/ml in the blood, 3.3 and 20.5 microg/ml in the urine. Distributions of phenol in fatal poisonings have been reported, but, usually, colorimetry was used as the analytical method and it cannot exclude the interference of other phenolic compounds.

Multiple muscles in the AMD quail can be "cross-corrected" of pathologic glycogen accumulation after intravenous injection of an [E1-, polymerase-] adenovirus vector encoding human acid-alpha-glucosidase

BACKGROUND

Previously, in murine models of acid maltase deficiency (AMD), we demonstrated that intravenous administration of an improved adenovirus (Ad) vector encoding human acid alpha glucosidase (hGAA) resulted in liver transduction, followed by high-level hepatocyte-mediated secretion of hGAA into the plasma space. The hGAA secreted by the liver was taken up and targeted to muscle cell lysosomes. The levels of hGAA achieved by this approach resulted in clearance of lysosomal glycogen accumulations; in some muscle tissues the effect was prolonged (>6 months). We next wished to demonstrate whether this approach could be generalized across divergent species. To accomplish this goal, we determined whether a similar approach would also result in efficacy, but in a quail model of AMD.

METHODS

An [E1-, E2b-]Ad vector encoding hGAA was intravenously injected into AMD quails. At several time points thereafter, plasma, liver, and multiple muscle tissues were assayed for evidence of hGAA gene expression, liver-mediated hGAA secretion, uptake of hGAA by skeletal muscles, and evidence of glycogen correction in AMD skeletal muscles. These results were compared with those obtained from mock-injected AMD or wild-type quails.

RESULTS

Intravenous [E1-, E2b-]Ad/hGAA vector injection resulted in high-level liver transduction and hepatic secretion of precursor forms of hGAA. The hepatically secreted hGAA was found to not only be efficiently taken up by cardiac and skeletal muscles, but was also proteolytically cleaved and processed equivalently to the quail-GAA protein detected in wild-type quails. The observations suggest that the signals regulating muscle cell uptake (but not proteolytic cleavage) of lysosomal enzymes are conserved and recognized across divergent species of vertebrates. Importantly, once localized to skeletal muscle lysosomes, the hGAA was able to effectively clear the glycogen accumulations present in AMD quail muscles.

CONCLUSIONS

Adenovirus-mediated transduction of the hGAA gene, followed by hepatic secretion, uptake, and cross-correction of the pathologic glycogen accumulation noted in multiple muscles of both the AMD mouse and AMD quail, adds support to the notion that gene transfer strategies (Ad-mediated or other agents) targeting liver tissues with the hGAA gene are likely to be highly efficacious in humans affected by AMD.

Structural model of the catalytic core of carnitine palmitoyltransferase I and carnitine octanoyltransferase (COT): mutation of CPT I histidine 473 and alanine 381 and COT alanine 238 impairs the catalytic activity

Carnitine palmitoyltransferase I (CPT I) and carnitine octanoyltransferase (COT) catalyze the conversion of long- and medium-chain acyl-CoA to acylcarnitines in the presence of carnitine. We propose a common three-dimensional structural model for the catalytic domain of both, based on fold identification for 200 amino acids surrounding the active site through a threading approach. The model is based on the three-dimensional structure of the rat enoyl-CoA hydratase, established by x-ray diffraction analysis. The study shows that the structural model of 200 amino acids of the catalytic site is practically identical in CPT I and COT with identical distribution of 4 beta-sheets and 6 alpha-helices. Functional analysis of the model was done by site-directed mutagenesis. When the critical histidine residue 473 in CPT I (327 in COT), localized in the acyl-CoA pocket in the model, was mutated to alanine, the catalytic activity was abolished. Mutation of the conserved alanine residue to aspartic acid, A381D (in CPT I) and A238D (in COT), which are 92/89 amino acids far from the catalytic histidine, respectively (but very close to the acyl-CoA pocket in the structural model), decreased the activity by 86 and 80%, respectively. The K(m) for acyl-CoA increased 6-8-fold, whereas the K(m) for carnitine hardly changed. The inhibition of the mutant CPT I by malonyl-CoA was not altered. The structural model explains the loss of activity reported for the CPT I mutations R451A, W452A, D454G, W391A, del R395, P479L, and L484P, all of which occur in or near the modeled catalytic domain.

Post-transcriptional regulation of rat carnitine octanoyltransferase

Carnitine octanoyltransferase (COT) produces three different transcripts in rat through cis- and trans-splicing reactions, which can lead to the synthesis of two proteins. The occurrence of the three COT transcripts in rat has been found in all tissues examined and does not depend on sex, fat feeding, peroxisome proliferators or hyperinsulinaemia. Rat COT exon 2 contains a putative exonic splicing enhancer (ESE) sequence. Mutation of this ESE (GAAGAAG) to AAAAAAA decreased trans-splicing in vitro, from which it is deduced that this ESE sequence is partly responsible for the formation of the three transcripts. The protein encoded by cis-spliced mRNA of rat COT is inhibited by malonyl-CoA and etomoxir. cDNA species encoding full-length wild-type COT and one double mutant COT were expressed in Saccharomyces cerevisiae. The recombinant enzymes showed full activity towards both substrates, carnitine and decanoyl-CoA. The activity of the doubly mutated H131A/H340A enzyme was similar to that of the rat peroxisomal enzyme but was completely insensitive to malonyl-CoA and etomoxir. These results indicate that the histidine residues His-131 and His-340 are the sites responsible for the interaction of these two inhibitors, which inhibit COT by interacting with the same sites.

Localization of an exonic splicing enhancer responsible for mammalian natural trans-splicing

Carnitine octanoyltransferase (COT) produces three different transcripts in rat through cis- and trans-splicing reactions, which may lead to the synthesis of two proteins. Generation of the three COT transcripts in rat does not depend on sex, development, fat feeding, the inclusion of the peroxisome proliferator diethylhexyl phthalate in the diet or hyperinsulinemia. In addition, trans-splicing was not detected in COT of other mammals, such as human, pig, cow and mouse, or in Cos7 cells from monkey. Rat COT exon 2 contains two purine-rich sequences. Mutation of the rat COT exon 2 upstream box does not affect the trans-splicing in vitro between two truncated constructs containing exon 2 and its adjacent intron boundaries. In contrast, mutation of the downstream box from the rat sequence (GAAGAAG) to a random sequence or the sequence observed in the other mammals (AAAAAAA) decreased trans-splicing in vitro. In contrast, mutation of the AAAAAAA box of human COT exon 2 to GAAGAAG increases trans-splicing. Heterologous reactions between COT exon 2 from rat and human do not produce trans-splicing. HeLa cells transfected with minigenes of rat COT sequences produced cis- and trans-spliced bands. Mutation of the GAAGAAG box to AAAAAAA abolished trans-splicing and decreased cis-splicing in vivo. We conclude that GAAGAAG is an exonic splicing enhancer that could induce natural trans-splicing in rat COT.

Adenovirus vectors with the 100K gene deleted and their potential for multiple gene therapy applications

The 100K protein has a number of critical roles vital for successful completion of the late phases of the adenovirus (Ad) life cycle. We hypothesized that the introduction of deletions within the 100K gene would allow for the production of a series of new classes of Ad vector, including one that is replication competent but blocked in the ability to carry out many late-phase Ad functions. Such a vector would have potential for several gene therapy applications, based upon its ability to increase the copy number of the transgene encoded by the vector (via genome replication) while decreasing the side effects associated with Ad late gene expression. To efficiently produce 100K-deleted Ad ([100K-]Ad) vectors, an E1- and 100K-complementing cell line (K-16) was successfully isolated. Transfection of an [E1-,100K-]Ad vector genome into the K-16 cells readily yielded high titers of the vector. After infection of noncomplementing cells, we demonstrated that [100K-]Ad vectors have a significantly decreased ability to express several Ad late genes. Additionally, if the E1 gene was present in the infected noncomplementing cells, [100K-]Ad vectors were capable of replicating their genomes to high copy number, but were significantly blocked in their ability to efficiently encapsidate the replicated genomes. Injection of an [E1-,100K-]Ad vector in vivo also correlated with significantly decreased hepatotoxicity, as well as prolonged vector persistence. In summary, the unique properties of [100K-]Ad vectors suggest that they may have utility in a variety of gene therapy applications.

Modulation in vitro of H-ras oncogene expression by trans-splicing

In man, activated N-, K- and H-ras oncogenes have been found in around 30% of the solid tumours tested. An exon known as IDX, which has been described previously and is located between exon 3 and exon 4A of the c-H-ras pre-mRNA, allows an alternative splicing process that results in the synthesis of the mRNA of a putative protein named p19. It has been suggested that this alternative pathway is less tumorigenic than that which results in the activation of p21. We have used the mammalian trans-splicing mechanism as a tool with which to modulate this particular pre-mRNA processing to produce mRNA similar to that of mature p19 RNA. The E4A exon of the activated H-ras gene was found to be a good target for external trans-splicing. We reprogrammed the rat carnitine octanoyltransferase exon 2 to specifically invade the terminal region of H-ras. Assays performed with this reprogrammed trans-exon showed that the trans-splicing product was obtained in competition with cis-splicing of the D intron of the H-ras gene, and was associated with concomitant down-modulation of D intron cis-splicing. We also found that the exon 4A of the human c-H-ras gene underwent successive trans-splicing rounds with an external exon.

Long-term efficacy after [E1-, polymerase-] adenovirus-mediated transfer of human acid-alpha-glucosidase gene into glycogen storage disease type II knockout mice

Glycogen storage disease type II (GSD-II) is a lethal, autosomal recessive metabolic myopathy caused by a lack of acid-alpha-glucosidase (GAA) activity in the cardiac and skeletal muscles. Absence of adequate intralysosomal GAA activity results in massive amounts of glycogen accumulation in multiple muscle groups, resulting in morbidity and mortality secondary to respiratory embarrassment and/or cardiomyopathy. In a mouse model of GSD-II, we demonstrate that infection of the murine liver with a modified adenovirus (Ad) vector encoding human GAA (hGAA) resulted in long-term persistence of the vector in liver tissues for at least 6 months. Despite both a rapid shutdown of hGAA mRNA expression from the vector, as well as the elicitation of anti-hGAA antibody responses (hGAA is a foreign antigen in this model), the hGAA secreted by the liver was taken up by all muscle groups analyzed and, remarkably, persisted in them for at least 6 months. The persistence of the protein also correlated with long-term correction of pathologic intramuscular glycogen accumulations in all muscle groups tested, but most notably the cardiac tissues, which demonstrated a significantly decreased glycogen content for at least 190 days after a single vector injection. The results suggest that gene therapy strategies may have the potential to significantly improve the clinical course for GSD-II patients.

Impaired hepatic fatty acid oxidation in rats with short-term cholestasis: characterization and mechanism

Rats with long-term cholestasis have reduced ketosis during starvation. Because it is unclear whether this is also the case in short-term cholestasis, we investigated hepatic fatty acid metabolism in rats with bile duct ligation for 5 days (BDL5, n = 11) or 10 days (BDL10, n = 11) and compared the findings with those made with pair-fed control rats (CON5 and CON10, n = 11). The plasma beta-hydroxybutyrate concentration was reduced in BDL rats (0.54 +/- 0.10 vs. 0.83 +/- 0.30 mM at 5 days and 0.59 +/- 0.24 vs. 0.88 +/- 0.09 mM at 10 days in BDL and control rats, respectively). In isolated liver mitochondria, state 3 oxidation rates for various substrates were not different between BDL and control rats. Production of ketone bodies from [(14)C]palmitate was reduced by 40% in mitochondria from BDL rats at both time points, whereas production of (14)CO(2) was maintained. These findings indicated intact function of the respiratory chain, Krebs cycle, and beta-oxidation and suggested impaired ketogenesis (HMG-CoA pathway). Accordingly, the formation of acetoacetate from acetyl-CoA by disrupted mitochondria was reduced in BDL rats at 5 days (2.1 +/- 1.0 vs. 4.8 +/- 1.9 nmol/min per mg protein) and at 10 days (1.7 +/- 1.0 vs. 6.2 +/- 1.9 nmol/min per mg protein). The principal defect could be localized at the rate-limiting enzyme of the HMG-CoA pathway, HMG-CoA synthase, which revealed decreased activity, and reduced hepatic mRNA and protein levels. We conclude that short-term cholestasis in rats leads to impaired hepatic fatty acid metabolism due to impaired ketogenesis. Ketogenesis is impaired because of decreased mRNA levels of HMG-CoA synthase, leading to reduced hepatic protein levels and to decreased activity of this key enzyme of ketogenesis. - Lang, C., M. Schäfer, D. Serra, F. G. Hegardt, L. Krähenbühl, and S. Krähenbühl. Impaired hepatic fatty acid oxidation in rats with short-term cholestasis: characterization and mechanism. J. Lipid Res. 2001. 42: 22;-30.

Developmental Changes in Carnitine Octanoyltransferase Gene Expression in Intestine and Liver of Suckling Rats

Carnitine octanoyltransferase (COT), which facilitates the transport of shortened fatty acyl-CoAs from peroxisomes to mitochondria, is expressed in the intestinal mucosa of suckling rats; its mRNA levels increase rapidly after birth, remain steady until day 15, and decrease until weaning, when basal, adult values are established, which remain unchanged thereafter. The process seems to be controlled at the transcriptional level since the developmental pattern of mRNA coincides with that of pre-mRNA values. Dam's milk may influence the intestinal expression of COT, since mRNA levels at birth are low and increase after the first lactation. Moreover, mRNA levels decrease in rats weaned on day 18 or 21. COT is also expressed in the liver of suckling rats. Hepatic COT mRNA is maximal at day 3, remains constant until day 9, and decreases thereafter; this pattern is also similar to that of pre-mRNA values. The profile of expression of COT in intestine and liver strongly resembles that of mitochondrial 3-hydroxy 3-methylglutaryl-coenzyme A synthase and carnitine palmitoyltransferase I, suggesting that analogous transcription factors modulate ketogenesis and mitochondrial and peroxisomal fatty acid oxidation.

Inhibition by etomoxir of rat liver carnitine octanoyltransferase is produced through the co-ordinate interaction with two histidine residues

Rat peroxisomal carnitine octanoyltransferase (COT), which facilitates the transport of medium-chain fatty acids through the peroxisomal membrane, is irreversibly inhibited by the hypoglycaemia-inducing drug etomoxir. To identify the molecular basis of this inhibition, cDNAs encoding full-length wild-type COT, two different variant point mutants and one variant double mutant from rat peroxisomal COT were expressed in Saccharomyces cerevisiae, an organism devoid of endogenous COT activity. The recombinant mutated enzymes showed activity towards both carnitine and decanoyl-CoA in the same range as the wild type. Whereas the wild-type version expressed in yeast was inhibited by etomoxir in an identical manner to COT from rat liver peroxisomes, the activity of the enzyme containing the double mutation H131A/H340A was completely insensitive to etomoxir. Individual point mutations H131A and H340A also drastically reduced sensitivity to etomoxir. Taken together, these results indicate that the two histidine residues, H131 and H340, are the sites responsible for inhibition by etomoxir and that the full inhibitory properties of the drug will be shown only if both histidines are intact at the same time. Our data demonstrate that both etomoxir and malonyl-CoA inhibit COT by interacting with the same sites.

Multiply deleted [E1, polymerase-, and pTP-] adenovirus vector persists despite deletion of the preterminal protein

BACKGROUND

The inherent limitations of [E1-]Ad vectors as gene therapy vehicles suggest that further modifications may improve their overall performance profiles. However, Ad vector modifications can have untoward effects on their basic biology, e.g., some helper-virus dependent Ad vectors have been found to be unstable without the presence of preterminal protein (pTP) activities. Despite this concern, we generated a new class of helper-virus independent Ad vector that was multiply deleted for the E1, polymerase, and pTP genes, and investigated the ramifications of these deletions upon several vector performance parameters.

METHODS

The construction and propagation of an [E1-, polymerase-, pTP-]Ad vector was achieved with the use of trans-complementing cells co-expressing the Ad E1, polymerase and pTP genes.

RESULTS

High titer production of the [E1-, polymerase-, pTP-]Ad vector was successfully accomplished via conventional Ad purification techniques. This unique class of Ad vector was capable of long-term gene transfer in vivo (despite lacking pTP functions) that was concomitant with a significantly decreased hepatic toxicity.

CONCLUSIONS

Previous studies had suggested that Ad genome persistence in vivo may be dependent upon the presence of low level vector genome replication and/or pTP functions. Our results suggest that [E1-, polymerase-, pTP-]Ad vectors can overcome these barriers. The further benefits afforded by the use of this class of Ad vector (increased cloning capacity, high level growth, decreased propensity to generate replication competent Ad (RCA), decreased toxicity) suggests that they will be highly beneficial for use in several aspects of human gene therapy.

Processing of carnitine octanoyltransferase pre-mRNAs by cis and trans-splicing

Trans-splicing is a mechanism by which two pre-mRNAs are processed to produce a mature transcript that contains exons from both precursors. This process has been described mostly in trypanosoma, nematodes, plant/algal chloroplasts and plant mitochondria [Bonen et al. (1993) FASEB J. 7, 40-46]. Our studies clearly demonstrate that a trans-splicing reaction occurs in the processing of the carnitine octanoyltransferase (COT) gene in rat liver. Three different mature transcripts of COT have been found in vivo, the canonical cis-spliced mRNA and two trans-spliced transcripts, in which either exon 2 or exons 2 and 3 are repeated. Splicing experiments in vitro also indicate the capacity of exon 2 to act either as a donor or as an acceptor of splicing, allowing the trans-splicing reactions to occur.

Identification of the two histidine residues responsible for the inhibition by malonyl-CoA in peroxisomal carnitine octanoyltransferase from rat liver

Carnitine octanoyltransferase (COT), an enzyme that facilitates the transport of medium chain fatty acids through peroxisomal membranes, is inhibited by malonyl-CoA. cDNAs encoding full-length wild-type COT and one double mutant variant from rat peroxisomal COT were expressed in Saccharomyces cerevisiae. Both expressed forms were expressed similarly in quantitative terms and exhibited full enzyme activity. The wild-type-expressed COT was inhibited by malonyl-CoA like the liver enzyme. The activity of the enzyme encoded by the double mutant H131A/H340A was completely insensitive to malonyl-CoA in the range assayed (2-200 microM). These results indicate that the two histidine residues, H131 and H340, are the sites responsible for inhibition by malonyl-CoA. Another mutant variant, H327A, abolishes the enzyme activity, from which it is concluded that it plays an important role in catalysis.