Effect of lipid peroxidation products on the activity of human retinol dehydrogenase 12 (RDH12) and retinoid metabolism

AbstractMutations in human Retinol Dehydrogenase 12 (RDH12) are known to cause photoreceptor cell death but the physiological function of RDH12 in photoreceptors remains poorly understood. In vitro, RDH12 recognizes both retinoids and medium-chain aldehydes as substrates. Our previous study suggested that RDH12 protects cells against toxic levels of retinaldehyde and retinoic acid [S.A. Lee, O.V. Belyaeva, I.K. Popov, N.Y. Kedishvili, Overproduction of bioactive retinoic acid in cells expressing disease-associated mutants of retinol dehydrogenase 12, J. Biol. Chem. 282 (2007) 35621–35628]. Here, we investigated whether RDH12 can also protect cells against highly reactive medium-chain aldehydes. Analysis of cell survival demonstrated that RDH12 was protective against nonanal but not against 4-hydroxynonenal. At high concentrations, nonanal inhibited the activity of RDH12 towards retinaldehyde, suggesting that nonanal was metabolized by RDH12. 4-Hydroxynonenal did not inhibit the RDH12 retinaldehyde reductase activity, but it strongly inhibited the activities of lecithin:retinol acyl transferase and aldehyde dehydrogenase, resulting in decreased levels of retinyl esters and retinoic acid and accumulation of unesterified retinol. Thus, the results of this study showed that RDH12 is more effective in protection against retinaldehyde than against medium-chain aldehydes, and that medium-chain aldehydes, especially 4-hydroxynonenal, severely disrupt cellular retinoid homeostasis. Together, these findings provide a new insight into the effects of lipid peroxidation products and the impact of oxidative stress on retinoid metabolism

Bargaining inequality: ways to overcome it in international commercial law and in private international law

The basic tenet of contract law is freedom of contract, including the freedom to negotiate and the autonomy of the will of the parties. However, practice and doctrine show that many international commercial contracts are formed in conditions of actual inequality of counterparties. The present work is the first comprehensive study of the problem of cross-border bargaining inequality among professional merchants. The aim of the study is to systematize and critically evaluate the effectiveness of legal conditions formulated in the unified acts of international commercial law and private international law to overcome inequality of counterparties at the pre-contractual stage. The study is based on logical, formal-legal and comparative-legal methods. The results and conclusions may be formulated as follows: (1) The set of legal means to resolve the problem of unequal position of the contracting parties is represented by a complex of complementary spheres of unified normative regulation - substantive norms and conflict-of-law norms. (2) Universal conventional legal regulation of the pre-contractual stage has not been developed. (3) Recommendatory acts of substantive unification of commercial law enshrine developed models of regulation of the parties’ conduct in cross-border negotiations. The main legal means to balance the position of the counterparties is the institution of the pre-contractual liability based on the principle of good faith. (4) Both in European law and in Russian law, the conflict-of-law issue is resolved through a combination of non-contractual qualification of the pre-contractual relations and the complex nature of regulation involving the consecutive use of contractual and tort-based connecting factors. (4) Where there is inequality, conflict-of-laws must provide for an equitable solution to situations where the choice of law applicable to each of the contracting parties is not truly free, including permitting a deviation from the principle of autonomy of will. (5) In the absence of parties’ choice of applicable law, the list of criteria for establishing the closest connection between the pre-contractual legal relation and the competent legal order should be expanded: the court should be able to consider the law of the future contractual obligations’ place of performance and the law governing other related contracts

Identical Functional Organization of Nonpolytene and Polytene Chromosomes in Drosophila melanogaster

Salivary gland polytene chromosomes demonstrate banding pattern, genetic meaning of which is an enigma for decades. Till now it is not known how to mark the band/interband borders on physical map of DNA and structures of polytene chromosomes are not characterized in molecular and genetic terms. It is not known either similar banding pattern exists in chromosomes of regular diploid mitotically dividing nonpolytene cells. Using the newly developed approach permitting to identify the interband material and localization data of interband-specific proteins from modENCODE and other genome-wide projects, we identify physical limits of bands and interbands in small cytological region 9F13-10B3 of the X chromosome in D. melanogaster, as well as characterize their general molecular features. Our results suggests that the polytene and interphase cell line chromosomes have practically the same patterns of bands and interbands reflecting, probably, the basic principle of interphase chromosome organization. Two types of bands have been described in chromosomes, early and late-replicating, which differ in many aspects of their protein and genetic content. As appeared, origin recognition complexes are located almost totally in the interbands of chromosomes

Lipoprotein Particles of Intraocular Origin in Human Bruch Membrane: An Unusual Lipid Profile

PURPOSE. Throughout adulthood, Bruch membrane (BrM) accumulates esterified cholesterol (EC) associated with abundant 60-to 80-nm-diameter lipoprotein-like particles (LLP), putative apolipoprotein B (apoB) lipoproteins secreted by the retinal pigment epithelium (RPE). In the present study, neutral lipid, phospholipids, and retinoid components of human BrM-LLP were assayed. METHODS. Particles isolated from paired choroids of human donors were subjected to comprehensive lipid profiling (preparative liquid chromatography [LC] gas chromatography [GC]), thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), Western blot analysis, and negative stain electron microscopy. Results were compared to plasma lipoproteins isolated from normolipemic volunteers and to conditioned medium from RPE-J cells supplemented with palmitate to induce particle synthesis and secretion. RESULTS. EC was the largest component (32.4 Ϯ 7.9 mol%) of BrM-LLP lipids. EC was 11.3-fold more abundant than triglyceride (TG), unlike large apoB lipoproteins in plasma. Of the fatty acids (FA) esterified to cholesterol, linoleate (18:2n6) was the most abundant (41.7 Ϯ 4.7 mol%). Retinyl ester (RE) was detectable at picomolar levels in BrM-LLP. Notably scarce in any BrM-LLP lipid class was the photoreceptor-abundant FA docosahexaenoate (DHA, 22:6n3). RPE-J cells synthesized apoB and numerous EC-rich spherical particles. CONCLUSIONS. BrM-LLP composition resembles plasma LDL more than it does photoreceptors. An EC-rich core is possible for newly synthesized lipoproteins as well as those processed in plasma. Abundant EC could contribute to a transport barrier in aging and lesion formation in age-related maculopathy (ARM). Analysis of BrM-LLP composition has revealed new aspects of retinal cholesterol and retinoid homeostasis. (Invest Ophthalmol Vis Sci. 2009;50:870 -877 2 Early ARM is characterized by drusen (focal extracellular debris), basal linear deposit (BlinD; a diffusely distributed drusenoid material), and altered RPE morphology and pigmentation. This disease stage has limited treatment options, including antioxidant nutritional supplements, and, in its later stages, loss of eyesight is possible. Although some gene sequence variants increase ARM risk, 3 the largest risk factor for early ARM remains advanced age. It is therefore important to understand how age-related changes in the affected tissues impel some individuals toward severe disease. Lipoproteins are naturally occurring nanoparticles composed of lipid and protein held together by noncovalent forces. Each particle is a microemulsion consisting of a surface of phospholipids (PLs), unesterified cholesterol (UC), and apolipoproteins and a core of neutral lipids, principally esterified cholesterol (EC) and triglyceride (TG). Lipoprotein classes differ in relative amount of lipids, protein/lipid ratio, and apolipoprotein species present, resulting in differences in size, density, and electrophoretic mobility. Lipoprotein classes containing apoB are chylomicrons (CM; from intestine), very-lowdensity lipoproteins (VLDL; from liver), and LDL (metabolite of VLDL). ApoB lipoproteins must be properly lipidated by their source cells in order for particle maturation and secretion to proceed. Core lipid composition reflects the availability of input FA and the substrate preferences of catalytic enzymes in upstream pathways. 10 Rather, recent evidence implicates EC as part of an apoB lipoprotein constitutively produced within the eye by the RPE and secreted into BrM, where it participates in ARM progression. Native human RPE expresses apolipoprotein mRNA transcripts, the proteins of apos B-100 and E, and notably, microsomal triglyceride transfer protein (MTP), required for apoB secretion and the product of the abetalipoproteinemia gene. 11,12 Isolated BrM-LLP segregate into the appropriate band of a density gradient but differ from plasma lipoproteins in cholesterol profile. 13 Cultured RPE secretes apoE, primarily into a high-density fraction. 14 Size and lipid composition are strongly related for apoB lipoproteins, in that particles Ͼ25 nm diameter (CM and VLDL) have TG-rich cores and smaller particles (including LDL) have EC-rich cores. 15 BrM-LLP, as large as VLDL or small CM, are expected to be TG-rich. Indeed, an early assay of BrM/choroid From the Departments of 1 Ophthalmology

Late Replication Domains in Polytene and Non-Polytene Cells of Drosophila melanogaster

In D. melanogaster polytene chromosomes, intercalary heterochromatin (IH) appears as large dense bands scattered in euchromatin and comprises clusters of repressed genes. IH displays distinctly low gene density, indicative of their particular regulation. Genes embedded in IH replicate late in the S phase and become underreplicated. We asked whether localization and organization of these late-replicating domains is conserved in a distinct cell type. Using published comprehensive genome-wide chromatin annotation datasets (modENCODE and others), we compared IH organization in salivary gland cells and in a Kc cell line. We first established the borders of 60 IH regions on a molecular map, these regions containing underreplicated material and encompassing ∼12% of Drosophila genome. We showed that in Kc cells repressed chromatin constituted 97% of the sequences that corresponded to IH bands. This chromatin is depleted for ORC-2 binding and largely replicates late. Differences in replication timing between the cell types analyzed are local and affect only sub-regions but never whole IH bands. As a rule such differentially replicating sub-regions display open chromatin organization, which apparently results from cell-type specific gene expression of underlying genes. We conclude that repressed chromatin organization of IH is generally conserved in polytene and non-polytene cells. Yet, IH domains do not function as transcription- and replication-regulatory units, because differences in transcription and replication between cell types are not domain-wide, rather they are restricted to small “islands” embedded in these domains. IH regions can thus be defined as a special class of domains with low gene density, which have narrow temporal expression patterns, and so displaying relatively conserved organization

17‐Beta Hydroxysteroid Dehydrogenase 13 Is a Hepatic Retinol Dehydrogenase Associated With Histological Features of Nonalcoholic Fatty Liver Disease

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148371/1/hep30350.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148371/2/hep30350_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148371/3/hep30350-sup-0001-Supinfo.pd

Genome-wide profiling of forum domains in Drosophila melanogaster

Forum domains are stretches of chromosomal DNA that are excised from eukaryotic chromosomes during their spontaneous non-random fragmentation. Most forum domains are 50–200 kb in length. We mapped forum domain termini using FISH on polytene chromosomes and we performed genome-wide mapping using a Drosophila melanogaster genomic tiling microarray consisting of overlapping 3 kb fragments. We found that forum termini very often correspond to regions of intercalary heterochromatin and regions of late replication in polytene chromosomes. We found that forum domains contain clusters of several or many genes. The largest forum domains correspond to the main clusters of homeotic genes inside BX-C and ANTP-C, cluster of histone genes and clusters of piRNAs. PRE/TRE and transcription factor binding sites often reside inside domains and do not overlap with forum domain termini. We also found that about 20% of forum domain termini correspond to small chromosomal regions where Ago1, Ago2, small RNAs and repressive chromatin structures are detected. Our results indicate that forum domains correspond to big multi-gene chromosomal units, some of which could be coordinately expressed. The data on the global mapping of forum domains revealed a strong correlation between fragmentation sites in chromosomes, particular sets of mobile elements and regions of intercalary heterochromatin

Место современных продуктов прикорма в критическом периоде формирования здоровья ребенка

The current development of medicine and the results of recent large-scale academic research in pediatrics provide the convincing conclusions that the formation of human health begins in the antenatal period of ontogenesis and continues throughout the infancy. The ideas and subsequent academic research on the influence of nutrition during the first thousand days of life on the programming of metabolism and the development of some chronic somatic diseases such as obesity, hypertension, coronary heart disease have become widespread. In addition, at the same period of life immune abnormalities with a predominance of one of the subpopulations, Th1 or Th2, can possibly form in children at risk of developing allergies when immune response is developing. The predominance of the Th2 cytokine profile (hyperproduction of interleukins 4, 5, 13, etc.) suggests the possibility of stable formation of the atopic status in a child afterwards. Consequently, the application of academic knowledge on the health status programming by nutrition during early ontogenesis is an important tool in preventive pediatric practice.Развитие современной медицины, результаты последних масштабных научных исследований в педиатрии приводят к убедительным выводам, что формирование здоровья человека начинается в антенатальном периоде онтогенеза и продолжается на протяжении раннего детского возраста. Широкое распространение получили идеи и последовавшие за ними научные исследования о влиянии питания первых тысячи дней жизни в программировании метаболизма и развитии некоторых хронических соматических болезней, таких как ожирение, гипертоническая болезнь, ишемическая болезнь сердца. Вместе с тем в этот же период жизни у детей групп риска по развитию аллергии при становлении иммунного ответа возможно программирование иммунных отклонений с преобладанием одной из субпопуляций — Th1 или Th2. Преобладание цитокинового профиля Th2 (гиперпродукция интерлейкинов 4, 5, 13 и др.) предполагает возможность стойкого формирования атопического статуса ребенка в дальнейшем. Следовательно, использование научных знаний о программировании состояния здоровья питанием в процессе раннего онтогенеза является важным инструментом в практической профилактической педиатрии.КОНФЛИКТ ИНТЕРЕСОВТ.В. Турти, Е.Г. Бокучава сотрудничают с АО «ПРОГРЕСС».И.А. Беляева сотрудничает с компанией «Пфайзер Инновации».Остальные авторы статьи подтвердили отсутствие конфликта интересов