Human DHRS7, promising enzyme in metabolism of steroids and retinoids?

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.

Valorization of wood chips ash as an eco-friendly mineral admixture in mortar mix design

Wood chips ash coming from biomass heating plant is studied as an eco-friendly mineral admixture in mortar mix design. The raw material was mechanically activated by milling in a vibratory disc mill to a degree of fineness comparable to cement. For the mortars with ash dosage, basic physical, mechanical, hygric, and thermal properties is accessed. The mortars with partial Portland cement replacement with wood chips ash exhibited good functional properties for all studied ash dosages. With increasing amount of the ash used, the average pore diameter decreased due to the partial filler effect of WCHA in mortar mix. The strength activity index was very high for all studied mortars and gave evidence of the wood chips ash pozzolanity. The pozzolan effectiveness coefficient varied from 1.52 to 0.59, which proved the pozzolanity of the studied ash and synergic effects in the Portland cement-ash-water system. The results of leaching tests showed, the chlorides contained in ash were safely immobilized in the silicate matrix. The environmental evaluation revealed decrease in both carbon dioxide production and energy consumption by the use of wood chips ash in mortar mix. For the mortar with 20% substitution of Portland cement with wood chips ash, it represents 15% of CO₂ and 16% of energy, as compared with the reference mortar mix. As the developed mortars possess good functional and environmental parameters the analyzed wood chips ash can be considered as an eco-efficient low-cost alternative to other pozzolans for production of blended binders.

Molecular and biochemical characterisation of human short-chain dehydrogenase/reductase member 3 (DHRS3)

Dehydrogenase/reductase (SDR family) member 3 (DHRS3), also known as retinal short-chain dehydrogenase/reductase (retSDR1) is a member of SDR16C family. This family is thought to be NADP(H) dependent and to have multiple substrates; however, to date, only all-trans-retinal has been identified as a DHRS3 substrate. The reductive reaction catalysed by DHRS3 seems to be physiological, and recent studies proved the importance of DHRS3 for maintaining suitable retinoic acid levels during embryonic development in vivo. Although it seems that DHRS3 is an important protein, knowledge of the protein and its properties is quite limited, with the majority of information being more than 15 years old. This study aimed to generate a more comprehensive characterisation of the DHRS3 protein. Recombinant enzyme was prepared and demonstrated to be a microsomal, integral-membrane protein with the C-terminus oriented towards the cytosol, consistent with its preference of NADPH as a cofactor. It was determined that DHRS3 also participates in the metabolism of other endogenous compounds, such as androstenedione, estrone, and DL-glyceraldehyde, and in the biotransformation of xenobiotics (e.g., NNK and acetohexamide) in addition to all-trans-retinal. Purified and reconstituted enzyme was prepared for the first time and will be used for further studies. Expression of DHRS3 was shown at the level of both mRNA and protein in the human liver, testis and small intestine. This new information could open other areas of DHRS3 protein research.

Small-molecule inhibitors of cyclophilin D as potential therapeutics in mitochondria-related diseases

Cyclophilin D (CypD) is a key regulator of mitochondrial permeability transition pore (mPTP) opening. This pathophysiological phenomenon is associated with the development of several human diseases, including ischemia-reperfusion injury and neurodegeneration. Blocking mPTP opening through CypD inhibition could be a novel and promising therapeutic approach for these conditions. While numerous CypD inhibitors have been discovered to date, none have been introduced into clinical practice, mostly owing to their high toxicity, unfavorable pharmacokinetics, and low selectivity for CypD over other cyclophilins. This review summarizes current knowledge of CypD inhibitors, with a particular focus on small-molecule compounds with regard to their in vitro activity, their selectivity for CypD, and their binding mode within the enzyme's active site. Finally, approaches for improving the molecular design of CypD inhibitors are discussed.

The identification of new substrates of human DHRS7 by molecular modeling and in vitro testing

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.

Initial characterization of human DHRS1 (SDR19C1), a member of the short-chain dehydrogenase/reductase superfamily

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.

AKR1C3 Inhibitory Potency of Naturally-occurring Amaryllidaceae Alkaloids of Different Structural Types

Aldo-keto reductase 1C3 (AKR1C3) is an important human enzyme that participates in the reduction of steroids and prostaglandins, which leads to proliferative signaling. AKR1C3 is frequently upregulated in various cancers, and this enzyme has been suggested as a therapeutic target for the treatment of these pathological conditions. The fact that the isoquinoline alkaloid stylopine has been identified as a potent AKR1C3 inhibitor has prompted us to screen a library of diverse types of Amaryllidaceae alkaloids, which biogenetically are isoquinoline alkaloids, on a recombinant form of AKR1C3. From the tested compounds, only tazettine showed moderate AKR1C3 inhibitory potency with an IC50 value of 15.8 ± 1.2 μM. Tazettine is a common Amaryllidaceae alkaloid, which could be used as a model substance for the further development of either analogues or related compounds with better inhibition potency.

Carbonyl-reducing enzymes as targets of a drug-immobilised affinity carrier

Proteins, peptides and nucleic acids are commonly isolated and purified in almost all bioscience laboratories. Methods based on molecular recognition are currently the most powerful tool in separation processes due to their selectivity and recovery. The aim of this study was to prove the versatility and the ability of an affinity carrier containing the immobilised ligand oracin (previously developed by our workgroup) to selectively bind carbonyl-reducing enzymes. These enzymes play an important role in metabolic pathways of various endogenic compounds and xenobiotics. Many important drugs, such as doxorubicin, daunorubicin, haloperidol and the model anticancer drug oracin, are metabolised by carbonyl-reducing enzymes. The functionality of the presented carrier was demonstrated with pure recombinant enzymes (AKR1A1, AKR1B1, AKR1B10, AKR1C1, AKR1C2, AKR1C3, AKR1C4, CBR1 and CBR3) as well as with two model biological samples (cell extract from genetically modified Escherichia coli and pre-purified human liver cytosol). Enzymes that show an affinity toward oracin were efficiently captured, gently eluted using 150 mM ammonium hydroxide and subsequently identified by MS. The method is highly selective and robust and may be applied to the purification and identification of various carbonyl-reducing enzymes from any biological sample.

Influence of wheat ash on the MCPA immobilization in agricultural soils

Burning of crop residues in the fields is a routine post-harvest practice and results in accumulation of ashes in soils. Recent studies have shown that the ashes may significantly contribute to the herbicide sorption in soils. This study was conducted to evaluate the potential role of wheat ash in immobilization of anionic herbicide MCPA in soils. The results showed that wheat ash is highly effective sorbent for herbicide MCPA. Amendment of Fluvi-Gleyic Phaeozem and Eutric Regosol with 1% wheat ash caused a 8-fold and 16-fold increase in MCPA sorption, respectively. Desorption of MCPA was also influenced by wheat ash in soils. The addition of wheat ash to both soils increased the resistant fraction to desorption up to 80%. Generally, the field burning of crop residues appears to increase the sorption of pesticides in agricultural soils and decrease their leaching.

Turbulence Models for Simulation of the Flow in a Rotor-Stator Cavity

Modelling of the flow in the cavities between rotor and stator in turbomachines (e.g. pumps or turbines) is a task of great interest. Correctly evaluated pressure and velocity fields enable calculation of the disk losses and therefore assessment of efficiency. It is also crucial for determination of axial thrust and thus design of the bearings. The study demonstrates abilities of various turbulence models to describe the flow in a narrow gap between rotating and stationary disks. Numerical simulations were performed in order to find out the ability of particular models to capture unstable structures appearing during specific operating conditions as well as to calculate the velocity profiles precisely. Large Eddy Simulation (LES), Scale Adaptive Simulation (SAS), Detached Eddy Simulation (DES), Reynolds stress model (RSM) and SSTk–ωmodel were used. Obtained results were also compared with experimental measurement published by Viazzo et al. [1]

Correction to "C-3 Steroidal Hemiesters as Inhibitors of 17β-Hydroxysteroid Dehydrogenase Type 10"

[This corrects the article DOI: 10.1021/acsomega.3c10148.].

Differential diagnosis of enterobacter agglomerans

On a number of instances, attempts to identify strains related to Ent. agglomerans by some of their characters were exemplified. Correlation with the tables proposed by EWING et al. was employed.

AKR1C3 Inhibitory Potency of Naturally-occurring Amaryllidaceae Alkaloids of Different Structural Types

Aldo-keto reductase 103 (AKRIC3) is an important human enzyme that participates in the reduction of steroids and prostaglandins, which leads to proliferative signaling. AKRIC3 is frequently upregulated in various cancers, and this enzyme has been suggested as a therapeutic target for the treatment of these pathological conditions. The fact that the isoquinoline alkaloid stylopine has been identified as a potent AKRIC3 inhibitor has prompted us to screen a library of diverse types of Amaryllidaceae alkaloids, which biogenetically are isoquinoline alkaloids, on a recombinant form of AKRIC3. From the tested compounds, only tazettine showed moderate AKRIC3 inhibitory potency with an IC5o value of 15.8 ? 1.2 pM. Tazettine is a common Amaryllidaceac alkaloid, which could be used as a model substance for the further development of either analogues or related compounds with better inhibition potency.

C-3 Steroidal Hemiesters as Inhibitors of 17β-Hydroxysteroid Dehydrogenase Type 10

17β-HSD10 is a mitochondrial enzyme that catalyzes the steroidal oxidation of a hydroxy group to a keto group and, thus, is involved in maintaining steroid homeostasis. The druggability of 17β-HSD10 is related to potential treatment for neurodegenerative diseases, for example, Alzheimer's disease or cancer. Herein, steroidal derivatives with an acidic hemiester substituent at position C-3 on the skeleton were designed, synthesized, and evaluated by using pure recombinant 17β-HSD10 converting 17β-estradiol to estrone. Compounds 22 (IC50 = 6.95 ± 0.35 μM) and 23 (IC50 = 5.59 ± 0.25 μM) were identified as the most potent inhibitors from the series. Compound 23 inhibited 17β-HSD10 activity regardless of the substrate. It was found not cytotoxic toward the HEK-293 cell line and able to inhibit 17β-HSD10 activity also in the cellular environment. Together, these findings support steroidal compounds as promising candidates for further development as 17β-HSD10 inhibitors.

Flow inside impeller sidewall gaps and disk friction of radial centrifugal pump

Disk friction losses can significantly influence the overall pump effciency. It is most pronounced in the case of machines with low or moderate specific speed, which has to be kept in mind during a design process of a pump. However, analyses using computational fluid dynamics (CFD) often completely neglect the sidewall gaps geometry. Correctly solved flow in the sidewall gaps can have a great impact on the whole flow pattern inside the pump and therefore it can considerably influence the calculated effciency. The paper is focused on the precise simulation of the flow in the spaces between impeller shrouds and casing. CFD study using embedded Large Eddy Simulation (LES) approach in order to achieve accurate insight into the flow in sidewall gaps and reasonable computational time was performed. Obtained results are compared with data from experimental measurements.