Dehydrogenase/reductase (SDR family) member 7 (DHRS7, retSDR4, SDR34C1) is a previously uncharacterized member of the short-chain dehydrogenase/reductase (SDR) superfamily. While human SDR members are known to play an important role in various (patho)biochemical pathways including intermediary metabolism and biotransformation of xenobiotics, only 20% of them are considered to be well characterized. Based on phylogenetic tree and SDR sequence clusters analysis DHRS7 is a close relative to well-known SDR member 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) that participates in metabolism of endogenous and xenobiotic substances with carbonyl group. The aim of present study is to determine the basic biochemical properties of DHRS7 and its possible involvement in metabolism of substrates with carbonyl group. For the first time the computational predictions of this membrane protein and membrane topology were experimentally confirmed. DHRS7 has been demonstrated to be an integral protein facing the lumen of the endoplasmic reticulum with lack of posttranscriptional glycosylation modification. Subsequently, NADP(H) cofactor preference and enzymatic reducing activity of DHRS7 was determined towards endogenous substrates with a steroid structure (cortisone, 4-androstene-3,17-dion) and also toward relevant exogenous substances bearing a carbonyl group harmful to human health (1,2-naphtoquinone, 9,10-phenantrenequinone). In addition to 11β-HSD1, DHRS7 is another enzyme from SDR superfamily that have been proved, at least in vitro, to contribute to the metabolism of xenobiotics with carbonyl group.

• Klíčová slova
• 11β-HSD1, 11β-hydroxysteroid dehydrogenase, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, DHRS7, ER, Membrane topology, NNAL, NNK, Oxidoreductase activity, SDR, SDR34C1, Short-chain dehydrogenases/reductases, dehydrogenase/reductase (SDR family) member 7, endoplasmic reticulum, short-chain dehydrogenases/reductases,
• MeSH
• 11-beta-hydroxysteroiddehydrogenasa typ 1 chemie   metabolismus   MeSH
• benzaldehydy metabolismus   MeSH
• fluorescenční protilátková technika MeSH
• intracelulární membrány metabolismus   MeSH
• izoenzymy chemie   metabolismus   MeSH
• jaterní mikrozomy enzymologie   MeSH
• kinetika MeSH
• lidé MeSH
• molekulární sekvence - údaje MeSH
• NAD metabolismus   MeSH
• NADP metabolismus   MeSH
• nitrosaminy chemie   metabolismus   MeSH
• oxidoreduktasy chemie   metabolismus   MeSH
• sekvence aminokyselin MeSH
• Sf9 buňky MeSH
• spektrofotometrie MeSH
• substrátová specifita MeSH
• ultracentrifugace MeSH
• western blotting MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 11-beta-hydroxysteroiddehydrogenasa typ 1 MeSH
• 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone MeSH Prohlížeč
• 4-nitrobenzaldehyde MeSH Prohlížeč
• benzaldehydy MeSH
• DHRS7 protein, human MeSH Prohlížeč
• DHRS7c protein, human MeSH Prohlížeč
• izoenzymy MeSH
• NAD MeSH
• NADP MeSH
• nitrosaminy MeSH
• oxidoreduktasy MeSH

Dehydrogenase/reductase (SDR family) member 8 (DHRS8, SDR16C2) belongs to the short-chain dehydrogenase/reductase (SDR) superfamily, one of the largest enzyme groups. In addition to the well-known members which participate in the metabolism of important eobiotics and xenobiotics, this superfamily contains many poorly characterized proteins. DHRS8 is a member of the Multisubstrate NADP(H)-dependent SDR16C family, which generally contains insufficiently described enzymes. Despite the limited knowledge about DHRS8, preliminary indicators have emerged regarding its significant function in the modulation of steroidal activity, at least in the case of 3α-adiol, lipid metabolism and detoxification. The aim of this study was to describe additional biochemical properties of DHRS8 and to unify knowledge about this enzyme. The DHRS8 was prepared in recombinant form and its membrane topology in the endoplasmic reticulum as an integral protein with cytosolic orientation was demonstrated. The enzyme participates in the NAD(+)-dependent oxidation of steroid hormones as β-estradiol and testosterone in vitro; apparent K m and V max values were 39.86 µM and 0.80 nmol × mg(-1) × min(-1) for β-estradiol and 1207.29 µM and 3.45 nmol × mg(-1) × min(-1) for testosterone. Moreover, synthetic steroids (methyltestosterone and nandrolone) used as anabolics as well as all-trans-retinol were for the first time identified as substrates of DHRS8. This knowledge of its in vitro activity together with a newly described expression pattern at the protein level in tissues involved in steroidogenesis (adrenal gland and testis) and detoxification (liver, lung, kidney and small intestine) could suggest a potential role of DHRS8 in vivo.

• Klíčová slova
• 17β-HSD11, DHRS8, Enzyme activity, Expression, Membrane topology, SDR16C2,
• MeSH
• katalýza MeSH
• lidé středního věku MeSH
• lidé MeSH
• oxidoreduktasy metabolismus   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• oxidoreduktasy MeSH

The best known, most widely studied enzyme system in phase I biotransformation is cytochrome P450 (CYP), which participates in the metabolism of roughly 9 of 10 drugs in use today. The main biotransformation isoforms of CYP are associated with the membrane of the endoplasmatic reticulum (ER). Other enzymes that are also active in phase I biotransformation are carbonyl reducing enzymes. Much is known about the role of cytosolic forms of carbonyl reducing enzymes in the metabolism of xenobiotics, but their microsomal forms have been mostly poorly studied. The only well-known microsomal carbonyl reducing enzyme taking part in the biotransformation of xenobiotics is 11β-hydroxysteroid dehydrogenase 1, a member of the short-chain dehydrogenase/reductase superfamily. Physiological roles of microsomal carbonyl reducing enzymes are better known than their participation in the metabolism of xenobiotics. This review is a summary of the fragmentary information known about the roles of the microsomal forms. Besides 11β-hydroxysteroid dehydrogenase 1, it has been reported, so far, that retinol dehydrogenase 12 participates only in the detoxification of unsaturated aldehydes formed upon oxidative stress. Another promising group of microsomal biotransformation carbonyl reducing enzymes are some members of 17β-hydroxysteroid dehydrogenases. Generally, it is clear that this area is, overall, quite unexplored, but carbonyl reducing enzymes located in the ER have proven very interesting. The study of these enzymes could shed new light on the metabolism of several clinically used drugs or they could become an important target in connection with some diseases.

• MeSH
• 11-beta-hydroxysteroiddehydrogenasa typ 1 metabolismus   MeSH
• 17-hydroxysteroidní dehydrogenasy metabolismus   MeSH
• alkoholoxidoreduktasy metabolismus   MeSH
• biotransformace MeSH
• endoplazmatické retikulum enzymologie   MeSH
• katalýza MeSH
• kyseliny karboxylové chemie   MeSH
• lidé MeSH
• mikrozomy enzymologie   MeSH
• molekulární struktura MeSH
• oxidace-redukce MeSH
• substrátová specifita MeSH
• xenobiotika chemie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• 11-beta-hydroxysteroiddehydrogenasa typ 1 MeSH
• 17-hydroxysteroidní dehydrogenasy MeSH
• 3 (or 17)-beta-hydroxysteroid dehydrogenase MeSH Prohlížeč
• alkoholoxidoreduktasy MeSH
• kyseliny karboxylové MeSH
• retinol dehydrogenase MeSH Prohlížeč
• xenobiotika MeSH

The metabolism of steroids and retinoids has been studied in detail for a long time, as these compounds are involved in a broad spectrum of physiological processes. Many enzymes participating in the conversion of such compounds are members of the short-chain dehydrogenase/reductase (SDR) superfamily. Despite great effort, there still remain a number of poorly characterized SDR proteins. According to various bioinformatics predictions, many of these proteins may play a role in the metabolism of steroids and retinoids. Dehydrogenase/reductase (SDR family) member 7 (DHRS7) is one such protein. In a previous study, we determined DHRS7 to be an integral membrane protein of the endoplasmic reticulum facing the lumen which has shown at least in vitro NADPH-dependent reducing activity toward several eobiotics and xenobiotics bearing a carbonyl moiety. In the present paper pure DHRS7 was used for a more detailed study of both substrate screening and an analysis of kinetics parameters of the physiologically important substrates androstene-3,17-dione, cortisone and all-trans-retinal. Expression patterns of DHRS7 at the mRNA as well as protein level were determined in a panel of various human tissue samples, a procedure that has enabled the first estimation of the possible biological function of this enzyme. DHRS7 is expressed in tissues such as prostate, adrenal glands, liver or intestine, where its activity could be well exploited. Preliminary indications show that DHRS7 exhibits dual substrate specificity recognizing not only steroids but also retinoids as potential substrates and could be important in the metabolism of these signalling molecules.

• Klíčová slova
• Carbonyl reduction, DHRS7, Metabolism, Retinoids, SDR, Steroids,
• MeSH
• androstendion metabolismus   MeSH
• cirkulární dichroismus MeSH
• fylogeneze MeSH
• kinetika MeSH
• kortison metabolismus   MeSH
• lidé MeSH
• oxidoreduktasy chemie   genetika   metabolismus   MeSH
• regulace genové exprese enzymů MeSH
• retinaldehyd metabolismus   MeSH
• steroidy metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• androstendion MeSH
• DHRS7 protein, human MeSH Prohlížeč
• DHRS7c protein, human MeSH Prohlížeč
• kortison MeSH
• oxidoreduktasy MeSH
• retinaldehyd MeSH
• steroidy MeSH

Many enzymes from the short-chain dehydrogenase/reductase superfamily (SDR) have already been well characterized, particularly those that participate in crucial biochemical reactions in the human body (e.g. 11β-hydroxysteroid dehydrogenase 1, 17β-hydroxysteroid dehydrogenase 1 or carbonyl reductase 1). Several other SDR enzymes are completely or almost completely uncharacterized, such as DHRS1 (also known as SDR19C1). Based on our in silico and experimental approaches, DHRS1 is described as a likely monotopic protein that interacts with the membrane of the endoplasmic reticulum. The highest expression level of DHRS1 protein was observed in human liver and adrenals. The recombinant form of DHRS1 was purified using the detergent n-dodecyl-β-D-maltoside, and DHRS1 was proven to be an NADPH-dependent reductase that is able to catalyse the in vitro reductive conversion of some steroids (estrone, androstene-3,17-dione and cortisone), as well as other endogenous substances and xenobiotics. The expression pattern and enzyme activities fit to a role in steroid and/or xenobiotic metabolism; however, more research is needed to fully clarify the exact biological function of DHRS1.

• Klíčová slova
• DHRS1, SDR superfamily, SDR19C1, Steroid hormones, Xenobiotics,
• MeSH
• dehydrogenasy/reduktasy s krátkým řetězcem metabolismus   MeSH
• endoplazmatické retikulum metabolismus   MeSH
• estron metabolismus   MeSH
• HeLa buňky MeSH
• játra metabolismus   MeSH
• kortison metabolismus   MeSH
• lidé MeSH
• nadledviny metabolismus   MeSH
• nádorové buněčné linie MeSH
• oxidoreduktasy genetika   metabolismus   MeSH
• rekombinantní proteiny biosyntéza   genetika   MeSH
• sekvence aminokyselin MeSH
• Sf9 buňky MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• dehydrogenasy/reduktasy s krátkým řetězcem MeSH
• DHRS1 protein, human MeSH Prohlížeč
• estron MeSH
• kortison MeSH
• oxidoreduktasy MeSH
• rekombinantní proteiny MeSH

This paper focuses on a channel feed-forward software defined equalization (FSDE) of visible light communication (VLC) multistate quadrature amplitude modulation (M-QAM) based system, implemented in the LabVIEW programming environment. A highly modular platform is introduced; the whole experiment is simulated in software and then thoroughly explored and analyzed during practical measurements in the laboratory, simulating real-world situations. The whole platform is based on modified National Instruments software defined radios (NI SDR) and a commercially available Philips light source, often used in Czech government institutions. Three FSDE algorithms were tested: least mean squares (LMS), normalized least mean squares (NLMS), and QR decomposition based RLS (QR-RLS). Based on measurements, QR-RLS provides the best results, improving measured values by up to 10%. The experiments also show that the simulated results are very similar to real measurements, thus proving the validity of the chosen approach. The whole platform manages to improve measured data simply by making changes to the software side of the testing prototype.

• Klíčová slova
• QR decomposition based recursive least squares (RLS), adaptive equalizers, feed-forward software defined equalization (FSDE), multistate quadrature amplitude modulation (M-QAM), software-defined radio (SDR), visible light communication (VLC),
• Publikační typ
• časopisecké články MeSH

OBJECTIVE: To measure the Knoop microhardness at the bottom of four posterior resin-based composites (RBCs): Tetric EvoCeram Bulk Fill (Ivoclar Vivadent), SureFil SDR flow (DENTSPLY), SonicFill (Kerr), and x-tra fil (Voco). METHODS: The RBCs were expressed into metal rings that were 2, 4, or 6-mm thick with a 4-mm internal diameter at 30°C. The uncured specimens were covered by a Mylar strip and a Bluephase 20i (Ivoclar Vivadent) polywave(®) LED light-curing unit was used in high power setting for 20s. The specimens were then removed and placed immediately on a Knoop microhardness-testing device and the microhardness was measured at 9 points across top and bottom surfaces of each specimen. Five specimens were made for each condition. RESULTS: As expected, for each RBC there was no significant difference in the microhardness values at the top of the 2, 4 and 6-mm thick specimens. SureFil SDR Flow was the softest resin, but was the only resin that had no significant difference between the KHN values at the bottom of the 2 and 4-mm (Mixed Model ANOVA p<0.05). Although the KHN of SureFil SDR Flow was only marginally significantly different between the 2 and 6-mm thickness, the bottom at 6-mm was only 59% of the hardness measured at the top. CLINICAL SIGNIFICANCE: This study highlights that clinicians need to consider how the depth of cure was evaluated when determining the depth of cure. SureFil SDR Flow was the softest material and, in accordance with manufacturer's instructions, this RBC should be overlaid with a conventional resin.

• Klíčová slova
• Broad spectrum LED curing light, Bulk fill resin based composites, Depth of cure, Knoop microhardness,
• MeSH
• akrylové pryskyřice chemie   účinky záření   MeSH
• analýza zatížení zubů MeSH
• bisfenol A-glycidyl methakrylát chemie   účinky záření   MeSH
• dentální adheziva tuhnoucí světlem přístrojové vybavení   metody   MeSH
• methakryláty chemie   účinky záření   MeSH
• polymerizace účinky záření   MeSH
• polyurethany chemie   účinky záření   MeSH
• povrchové vlastnosti účinky záření   MeSH
• složené pryskyřice chemie   účinky záření   MeSH
• stomatologické polymerizační lampy * MeSH
• testování materiálů MeSH
• zubní materiály chemie   účinky záření   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• akrylové pryskyřice MeSH
• bisfenol A-glycidyl methakrylát MeSH
• Foundation composite resin MeSH Prohlížeč
• methakryláty MeSH
• polyurethany MeSH
• složené pryskyřice MeSH
• SonicFill MeSH Prohlížeč
• Surefil SDR Flow MeSH Prohlížeč
• Tetric EvoCeram MeSH Prohlížeč
• Vivadent MeSH Prohlížeč
• X-tra fil composite resin MeSH Prohlížeč
• zubní materiály MeSH

Human DHRS7 (SDR34C1) is one of insufficiently described enzymes of the short-chain dehydrogenase/reductase superfamily. The members of this superfamily often play an important pato/physiological role in the human body, participating in the metabolism of diverse substrates (e.g. retinoids, steroids, xenobiotics). A systematic approach to the identification of novel, physiological substrates of DHRS7 based on a combination of homology modeling, structure-based virtual screening and experimental evaluation has been used. Three novel substrates of DHRS7 (dihydrotestosterone, benzil and 4,4'-dimetylbenzil) have been described.

• Klíčová slova
• DHRS7, Homology modeling, Molecular modeling, SDR superfamily, SDR34C1,
• MeSH
• dihydrotestosteron metabolismus   MeSH
• fenylglyoxal analogy a deriváty   metabolismus   MeSH
• konformace proteinů MeSH
• lidé MeSH
• oxidoreduktasy chemie   metabolismus   MeSH
• simulace molekulového dockingu MeSH
• vazba proteinů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 4,4'-dimethylbenzil MeSH Prohlížeč
• benzil MeSH Prohlížeč
• DHRS7 protein, human MeSH Prohlížeč
• dihydrotestosteron MeSH
• fenylglyoxal MeSH
• oxidoreduktasy MeSH

Short-chain dehydrogenases/reductases (SDRs) regulate the activities of many hormones and other signaling molecules and participate in the deactivation of various carbonyl-bearing xenobiotics. Nevertheless, knowledge about these important enzymes in helminths remains limited. The aim of our study was to characterize the SDR superfamily in the parasitic nematode Haemonchus contortus. Genome localization of SDRs was explored, and phylogenetic analysis in comparison with SDRs from free-living nematode Caenorhabditis elegans and the domestic sheep (Ovis aries, a typical host of H. contortus) was constructed. The expression profile of selected SDRs during the life cycle along with differences between the drug-susceptible and drug-resistant strains, were also studied. Genome sequencing enabled the identification of 46 members of the SDR family in H. contortus. A number of genes have no orthologue in the sheep genome. In all developmental stages of H. contortus, SDR1, SDR3, SDR5, SDR6, SDR14, and SDR18 genes were the most expressed, although in individual stages, huge differences in expression levels were observed. A comparison of SDRs expression between the drug-susceptible and drug-resistant strains of H. contortus revealed several SDRs with changed expression in the resistant strain. Specifically, SDR1, SDR12, SDR13, SDR16 are SDR candidates related to drug-resistance, as the expression of these SDRs is consistently increased in most stages of the drug-resistant H. contortus. These findings revealing several SDR enzymes of H. contortus warrant further investigation.

• Klíčová slova
• Haemonchus contortus, SDRs, drug-resistant strain, drug-susceptible strain, expression profile, phylogenetic analysis,
• MeSH
• fylogeneze MeSH
• Haemonchus * genetika   MeSH
• ovce MeSH
• stadia vývoje MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Enzymatic carbonyl reduction means the formation of a hydroxy function out of a ketone or aldehyde moiety and applies for the metabolism of physiological (endogenous) or xenobiotic (exogenous) molecules. As for endogenous substrates, carbonyl reduction is often part of a reversible oxidoreductase process and involves the activation or inactivation of important signal molecules like steroids, prostaglandins, retinoids and biogenic amines. These reactions are carried out by NAD(P)(H)-dependent dehydrogenases belonging to two protein superfamilies, the aldo-keto reductases (AKR) and the short-chain dehydrogenases/reductases (SDR). With regard to exogenous substrates, carbonyl reduction of xenobiotics is generally a "one-way" detoxification reaction, since the resulting alcohol is easier to conjugate and to eliminate. Interestingly, the participating enzymes do also belong to the AKR and SDR superfamilies. Moreover, some enzymes from the two protein superfamilies exhibit pluripotency in that they are able to catalyze the oxidoreduction of endobiotics but do also function in the reductive metabolism of carbonyl group bearing xenobiotics. A special case are carbonyl reductases per se which belong to the SDR superfamily and whose substrates or physiological roles are not quite clear. Usually, carbonyl reductases have a broad and diverse substrate spectrum for xenobiotics, however, for some of them a specific physiological function has been speculated. In the human genome, three SDR genes have been identified to code for the carbonyl reductases CBR1 (SDR21C1), CBR3 (SDR21C2) and CBR4 (SDR45C1). The present review summarizes the current knowledge on these enzymes with special emphasis on their role as a defence system against toxicants, as well as their possible physiological function and medical application. In detail, we have screened the recent literature on these three enzymes with regard to endogenous and exogenous substrates, their three-dimensional structure, tissues specific expression, polymorphisms, transcriptional regulation, occurrence in pathological states, and their possible association with cancer. Combined, this review contributes to understanding the complex nature and biological roles(s) of the human carbonyl reductases CBR1, CBR3 and CBR4.

• MeSH
• alkoholoxidoreduktasy chemie   genetika   metabolismus   MeSH
• exprese genu MeSH
• lidé MeSH
• mitochondriální proteiny chemie   genetika   metabolismus   MeSH
• NAD(P)H dehydrogenasa (chinon) chemie   genetika   metabolismus   MeSH
• polymorfismus genetický MeSH
• xenobiotika metabolismus   toxicita   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• alkoholoxidoreduktasy MeSH
• CBR1 protein, human MeSH Prohlížeč
• CBR3 protein, human MeSH Prohlížeč
• CBR4 protein, human MeSH Prohlížeč
• mitochondriální proteiny MeSH
• NAD(P)H dehydrogenasa (chinon) MeSH
• xenobiotika MeSH