Professor Richard Jenkins

Job: Emeritus Professor

Faculty: Health and Life Sciences

School/department: School of Allied Health Sciences

Address: De Montfort University, The Gateway, Leicester, LE1 9BH.

T: N/A

E: richard.jenkins@dmu.ac.uk

W: https://www.dmu.ac.uk/hls

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Personal profile

Professor Jenkins holds a first class degree in microbiology with biochemistry and a PhD in yeast physiology. His postdoctoral research was with Professor Sir Howard Dalton at the University of Warwick, investigating microbial biotransformations of aromatic hydrocarbons. Since joining De Montfort University, he has pursued various research interests involving the interaction of microbiological systems with chemicals (including antimony and arsenic compounds, chlorinated ethylenes) and various man-made environments (infant mattresses, water courses, landfills). His other research interests are the mechanistic action of certain metabolic poisons (fluoroacetate, organophosphates), human exposure to toxic metals and metalloids, and spectroscopic characterisation of cells (human and microbial).

Research group affiliations

Institute of Allied Health Sciences

Publications and outputs

Anticholinesterase and Serotoninergic Evaluation of Benzimidazole–Carboxamides as Potential Multifunctional Agents for the Treatment of Alzheimer’s Disease
dc.title: Anticholinesterase and Serotoninergic Evaluation of Benzimidazole–Carboxamides as Potential Multifunctional Agents for the Treatment of Alzheimer’s Disease dc.contributor.author: Belinskaia, D.A.; Voronina, P.A.; Krivorotov, D.V.; Jenkins, R.O.; Goncharov, N. V. dc.description.abstract: The etiology and pathogenesis of Alzheimer’s disease are multifactorial, so one of the treatment strategies is the development of the drugs that affect several targets associated with the pathogenesis of the disease. Within this roadmap, we investigated the interaction of several substituted 1,3-dihydro-2-oxo-1H-benzimidazol-2-ones with their potential molecular targets: cholinesterases (ChE) and three types of the Gs-protein-coupled serotonin receptors (5-HTR) 5-HT6, 5-HT4 and 5-HT7 (5-HT4R, 5-HT6R and 5-HT7R, respectively). A microplate modification of the Ellman method was used for the biochemical analysis of the inhibitory ability of the drugs towards ChE. Molecular modeling methods, such as molecular docking and molecular dynamics (MD) simulation in water and the lipid bilayer, were used to study the interaction of the compounds with ChE and 5-HTR. In vitro experiments showed that the tested compounds had moderate anticholinesterase activity. With the help of molecular modeling methods, the mechanism of interaction of the tested compounds with ChE was investigated, the binding sites were described and the structural features of the drugs that determine the strength of their anticholinesterase activity were revealed. Primary in silico evaluation showed that benzimidazole–carboxamides effectively bind to 5-HT4R and 5-HT7R. The pool of the obtained data allows us to choose N-[2-(diethylamino)ethyl]-2-oxo-3-(tert-butyl)-2,3-dihydro-1H-benzimidazole-1-carboxamide hydrochloride (compound 13) as the most promising for further experimental development. dc.description: open access article
Molecular Basis for the Involvement of Mammalian Serum Albumin in the AGE/RAGE Axis: A Comprehensive Computational Study
dc.title: Molecular Basis for the Involvement of Mammalian Serum Albumin in the AGE/RAGE Axis: A Comprehensive Computational Study dc.contributor.author: Belinskaia, D. A.; Jenkins, R. O.; Goncharov, N. V. dc.description.abstract: In mammals, glycated serum albumin (gSA) contributes to the pathogenesis of many metabolic diseases by activating the receptors (RAGE) for advanced glycation end products (AGEs). Many aspects of the gSA–RAGE interaction remain unknown. The purpose of the present paper was to study the interaction of glycated human albumin (gHSA) with RAGE using molecular modeling methods. Ten models of gHSA modified with different lysine residues to carboxymethyl-lysines were prepared. Complexes of gHSA–RAGE were obtained by the macromolecular docking method with subsequent molecular dynamics simulation (MD). According to the MD, the RAGE complexes with gHSA glycated at Lys233, Lys64, Lys525, Lys262 and Lys378 are the strongest. Three-dimensional models of the RAGE dimers with gHSA were proposed. Additional computational experiments showed that the binding of fatty acids (FAs) to HSA does not affect the ability of Lys525 (the most reactive lysine) to be glycated. In contrast, modification of Lys525 reduces the affinity of albumin for FA. The interspecies differences in the molecular structure of albumin that may affect the mechanism of the gSA–RAGE interaction were discussed. The obtained results will help us to learn more about the molecular basis for the involvement of serum albumin in the AGE/RAGE axis and improve the methodology for studying cellular signaling pathways involving RAGE. dc.description: open access article
Immunological Profile and Markers of Endothelial Dysfunction in Elderly Patients with Cognitive Impairments.
dc.title: Immunological Profile and Markers of Endothelial Dysfunction in Elderly Patients with Cognitive Impairments. dc.contributor.author: Goncharov, N. V.; Popova, P. I.; KUDRYAVTSEV, I. V.; GOLOVKIN, A. S.; SAVITSKAYA, I. V.; AVDONIN, P. P.; Korf, E. A.; VOITENKO, N. G.; Belinskaia, D. A.; SEREBRYAKOVA, M. K.; MATVEEVA, N. V.; GERLAKH, N. O.; ANIKIEVICH, N. E.; GUBATENKO, M. A.; DOBRYLKO, I. A.; TRULIOFF, A. S.; AQUINO, A.; Jenkins, R. O.; AVDONIN, P. V. dc.description.abstract: The process of aging is accompanied by a dynamic restructuring of the immune response, a phenomenon known as immunosenescence. Further, damage to the endothelium can be both a cause and a consequence of many diseases, especially in elderly people. The purpose of this study was to carry out immunological and biochemical profiling of elderly people with acute ischemic stroke (AIS), chronic cerebral circulation insufficiency (CCCI), prediabetes or newly diagnosed type II diabetes mellitus (DM), and subcortical ischemic vascular dementia (SIVD). Socio-demographic, lifestyle, and cognitive data were obtained. Biochemical, hematological, and immunological analyses were carried out, and extracellular vesicles (EVs) with endothelial CD markers were assessed. The greatest number of significant deviations from conditionally healthy donors (HDs) of the same age were registered in the SIVD group, a total of 20, of which 12 were specific and six were non-specific but with maximal differences (as compared to the other three groups) from the HDs group. The non-specific deviations were for the MOCA (Montreal Cognitive Impairment Scale), the MMSE (Mini Mental State Examination) and life satisfaction self-assessment scores, a decrease of albumin levels, and ADAMTS13 (a Disintegrin and Metalloproteinase with a Thrombospondin Type 1 motif, member 13) activity, and an increase of the VWF (vonWillebrand factor) level. Considering the significant changes in immunological parameters (mostly Th17-like cells) and endothelial CD markers (CD144 and CD34), vascular repair was impaired to the greatest extent in the DM group. The AIS patients showed 12 significant deviations from the HD controls, including three specific to this group. These were high NEFAs (non-esterified fatty acids) and CD31 and CD147 markers of EVs. The lowest number of deviations were registered in the CCCI group, nine in total. There were significant changes from the HD controls with no specifics to this group, and just one non-specific with a maximal difference from the control parameters, which was 1-AGP (alpha 1 acid glycoprotein, orosomucoid). Besides the DM patients, impairments of vascular repair were also registered in the CCCI and AIS patients, with a complete absence of such in patients with dementia (SIVD group). On the other hand, microvascular damage seemed to be maximal in the latter group, considering the biochemical indicators VWF and ADAMTS13. In the DMpatients, a maximum immune response was registered, mainly with Th17-like cells. In the CCCI group, the reaction was not as pronounced compared to other groups of patients, which may indicate the initial stages and/or compensatory nature of organic changes (remodeling). At the same time, immunological and biochemical deviations in SIVD patients indicated a persistent remodeling in microvessels, chronic inflammation, and a significant decrease in the anabolic function of the liver and other tissues. The data obtained support two interrelated assumptions. Taking into account the primary biochemical factors that trigger the pathological processes associated with vascular pathology and related diseases, the first assumption is that purine degradation in skeletal muscle may be a major factor in the production of uric acid, followed by its production by non-muscle cells, the main of which are endothelial cells. Another assumption is that therapeutic factors that increase the levels of endothelial progenitor cells may have a therapeutic effect in reducing the risk of cerebrovascular disease and related neurodegenerative diseases. dc.description: open access article
Serum Albumin in Health and Disease: From Comparative Biochemistry to Translational Medicine
dc.title: Serum Albumin in Health and Disease: From Comparative Biochemistry to Translational Medicine dc.contributor.author: Belinskaia, D. A.; Jenkins, R. O.; Goncharov, V. A. dc.description: open access article
Albumin Is a Component of the Esterase Status of Human Blood Plasma
dc.title: Albumin Is a Component of the Esterase Status of Human Blood Plasma dc.contributor.author: Belinskaia, D. A.; Voronina, P. A.; Popova, P. I.; Voitenko, N. G.; Shmurak, V. I.; Vovk, M. A.; Baranova, T. I.; Batalova, A. A.; Korf, E. A.; Avdonin, P. V.; Jenkins, R. O.; Goncharov, N. V. dc.description.abstract: The esterase status of blood plasma can claim to be one of the universal markers of various diseases; therefore, it deserves attention when searching for markers of the severity of COVID-19 and other infectious and non-infectious pathologies. When analyzing the esterase status of blood plasma, the esterase activity of serum albumin, which is the major protein in the blood of mammals, should not be ignored. The purpose of this study is to expand understanding of the esterase status of blood plasma and to evaluate the relationship of the esterase status, which includes information on the amount and enzymatic activity of human serum albumin (HSA), with other biochemical parameters of human blood, using the example of surviving and deceased patients with confirmed COVID-19. In experiments in vitro and in silico, the activity of human plasma and pure HSA towards various substrates was studied, and the effect of various inhibitors on this activity was tested. Then, a comparative analysis of the esterase status and a number of basic biochemical parameters of the blood plasma of healthy subjects and patients with confirmed COVID-19 was performed. Statistically significant differences have been found in esterase status and biochemical indices (including albumin levels) between healthy subjects and patients with COVID-19, as well as between surviving and deceased patients. Additional evidence has been obtained for the importance of albumin as a diagnostic marker. Of particular interest is a new index, [Urea] x [MDA] x 1000/(BChEb x [ALB]), which in the group of deceased patients was 10 times higher than in the group of survivors and 26 times higher than the value in the group of apparently healthy elderly subjects. dc.description: open access article
Molecular Mechanisms of Acute Organophosphate Nephrotoxicity
dc.title: Molecular Mechanisms of Acute Organophosphate Nephrotoxicity dc.contributor.author: Sobolev, V. E.; Sokolova, M. O.; Goncharov, N. V.; Jenkins, R. O. dc.description.abstract: Organophosphates (OPs) are toxic chemicals produced by an esterification process and some other routes. They are the main components of herbicides, pesticides, and insecticides and are also widely used in the production of plastics and solvents. Acute or chronic exposure to OPs can manifest in various levels of toxicity to humans, animals, plants, and insects. OPs containing insecticides were widely used in many countries during the 20th century, and some of them continue to be used today. In particular, 36 OPs have been registered in the USA, and all of them have the potential to cause acute and sub-acute toxicity. Renal damage and impairment of kidney function after exposure to OPs, accompanied by the development of clinical manifestations of poisoning back in the early 1990s of the last century, was considered a rare manifestation of their toxicity. However, since the beginning of the 21st century, nephrotoxicity of OPs as a manifestation of delayed toxicity is the subject of greater attention of researchers. In this article, we present a modern view on the molecular pathophysiological mechanisms of acute nephrotoxicity of organophosphate compounds. dc.description: open access article
Survival of Clostridioides difficile spores in thermal and chemo-thermal laundering processes and influence of the exosporium on their adherence to cotton bed sheets
dc.title: Survival of Clostridioides difficile spores in thermal and chemo-thermal laundering processes and influence of the exosporium on their adherence to cotton bed sheets dc.contributor.author: Owen, Lucy; Laird, Katie; Jenkins, R. O.; Tarrant, Joanna; Smith, Laura J. dc.description.abstract: Clostridioides difficile spores were previously demonstrated to survive industrial laundering. Understanding interactions between heat, disinfectants and soiling (e.g. bodily fluids) affecting C. difficile spore survival could inform the optimization of healthcare laundry processes. Reducing spore attachment to linen could also enhance laundering efficacy. This study aimed to compare the sensitivity of C. difficile spores to heat and detergent, with and without soiling and to investigate adherence to cotton. Survival of C. difficile spores exposed to industrial laundering temperatures (71–90°C), reference detergent and industrial detergent was quantified with and without soiling. The adherence to cotton after 0 and 24 h air drying was determined with the exosporium of C. difficile spores partially or fully removed. Clostridioides difficile spores were stable at 71°C for 20 min (≤0·37 log10 reduction) while 90°C was sporicidal (3 log10 reduction); soiling exerted a protective effect. Industrial detergent was more effective at 71°C compared to 25°C (2·81 vs 0·84 log10 reductions), however, specifications for sporicidal activity (>3 log10 reduction) were not met. Clostridioides difficile spores increasingly adhered to cotton over time, with 49% adherence after 24 h. Removal of the exosporium increased adherence by 19–23% compared to untreated spores. Further understanding of the role of the exosporium in attachment to cotton could enhance spore removal and aid decontamination of linen. dc.description: open access article
Serum albumin in health and disease: esterase, antioxidant, transporting and signaling properties
dc.title: Serum albumin in health and disease: esterase, antioxidant, transporting and signaling properties dc.contributor.author: BELINSKAIA, D.A.; VORONINA, P.A.; SHMURAK, V.I.; Jenkins, R. O.; GONCHAROV, N.V. dc.description.abstract: Being one of the main proteins in the human body and many animal species, albumin plays a decisive role in the transport of various ions—electrically neutral and charged molecules—and in maintaining the colloidal osmotic pressure of the blood. Albumin is able to bind to almost all known drugs, as well as many nutraceuticals and toxic substances, largely determining their pharmaco and toxicokinetics. Albumin of humans and respective representatives in cattle and rodents have their own structural features that determine species differences in functional properties. However, albumin is not only passive, but also an active participant of pharmacokinetic and toxicokinetic processes, possessing a number of enzymatic activities. Numerous experiments have shown esterase or pseudoesterase activity of albumin towards a number of endogeneous and exogeneous esters. Due to the free thiol group of Cys34, albumin can serve as a trap for reactive oxygen and nitrogen species, thus participating in redox processes. Glycated albumin makes a significant contribution to the pathogenesis of diabetes and other diseases. The interaction of albumin with blood cells, blood vessels and tissue cells outside the vascular bed is of great importance. Interactions with endothelial glycocalyx and vascular endothelial cells largely determine the integrative role of albumin. This review considers the esterase, antioxidant, transporting and signaling properties of albumin, as well as its structural and functional modifications and their significance in the pathogenesis of certain diseases. dc.description: The Publisher's final version can be found by following the DOI link. Open access article.
Nephrotoxic effects of paraoxon in three rat models of acute intoxication
dc.title: Nephrotoxic effects of paraoxon in three rat models of acute intoxication dc.contributor.author: SOBOLEV, V.E.; SOKOLOVA, M.O.; Jenkins, R. O.; GONCHAROV, N.V. dc.description.abstract: The delayed effects of acute intoxication by organophosphates (OPs) are poorly understood, and the various experimental animal models often do not take into account species characteristics. The principal biochemical feature of rodents is the presence of carboxylesterase in blood plasma, which is a target for OPs and can greatly distort their specific effects. The present study was designed to investigate the nephrotoxic effects of paraoxon (O,O-diethyl O-(4-nitrophenyl) phosphate, POX) using three models of acute poisoning in outbred Wistar rats. In the first model (M1, POX2x group), POX was administered twice at doses 110 µg/kg and 130 µg/kg subcutaneously, with an interval of 1 h. In the second model (M2, CBPOX group), 1 h prior to POX poisoning at a dose of 130 µg/kg subcutaneously, carboxylesterase activity was pre-inhibited by administration of specific inhibitor cresylbenzodioxaphosphorin oxide (CBDP, 3.3 mg/kg intraperitoneally). In the third model (M3), POX was administered subcutaneously just once at doses of LD16 (241 µg/kg), LD50 (250 µg/kg), and LD84 (259 µg/kg). Animal observation and sampling were performed 1, 3, and 7 days after the exposure. Endogenous creatinine clearance (ECC) decreased in 24 h in the POX2x group (p = 0.011). Glucosuria was observed in rats 24 h after exposure to POX in both M1 and M2 models. After 3 days, an increase in urinary excretion of chondroitin sulfate (CS, p = 0.024) and calbindin (p = 0.006) was observed in rats of the CBPOX group. Morphometric analysis revealed a number of differences most significant for rats in the CBPOX group. Furthermore, there was an increase in the area of the renal corpuscles (p = 0.0006), an increase in the diameter of the lumen of the proximal convoluted tubules (PCT, p = 0.0006), and narrowing of the diameter of the distal tubules (p = 0.001). After 7 days, the diameter of the PCT lumen was still increased in the nephrons of the CBPOX group (p = 0.0009). In the M3 model, histopathological and ultrastructural changes in the kidneys were revealed after the exposure to POX at doses of LD50 and LD84. Over a period from 24 h to 3 days, a significant (p = 0.018) expansion of Bowman’s capsule was observed in the kidneys of rats of both the LD50 and LD84 groups. In the epithelium of the proximal tubules, stretching of the basal labyrinth, pycnotic nuclei, and desquamation of microvilli on the apical surface were revealed. In the epithelium of the distal tubules, partial swelling and destruction of mitochondria and pycnotic nuclei was observed, and nuclei were displaced towards the apical surface of cells. After 7 days of the exposure to POX, an increase in the thickness of the glomerular basement membrane (GBM) was observed in the LD50 and LD84 groups (p = 0.019 and 0.026, respectively). Moreover, signs of damage to tubular epithelial cells persisted with blockage of the tubule lumen by cellular detritus and local destruction of the surface of apical cells. Comparison of results from the three models demonstrates that the nephrotoxic effects of POX, evaluated at 1 and 3 days, appear regardless of prior inhibition of carboxylesterase activity. dc.description: open access article.
Esterase activity of serum albumin studied by 1H NMR spectroscopy and molecular modelling
dc.title: Esterase activity of serum albumin studied by 1H NMR spectroscopy and molecular modelling dc.contributor.author: BELINSKAIA, D.A.; VORONINA, P.A.; VOVK, M.A.; SHMURAK, V.I.; BATALOVA, A.A.; Jenkins, R. O.; GONCHAROV, N.V. dc.description.abstract: Serum albumin possesses esterase and pseudo-esterase activities towards a number of endogenous and exogenous substrates, but the mechanism of interaction of various esters and other compounds with albumin is still unclear. In the present study, proton nuclear magnetic resonance ( 1H NMR) has been applied to the study of true esterase activity of albumin, using the example of bovine serum albumin (BSA) and p-nitrophenyl acetate (NPA). The site of BSA esterase activity was then determined using molecular modelling methods. According to the data obtained, the accumulation of acetate in the presence of BSA in the reaction mixture is much more intense as compared with the spontaneous hydrolysis of NPA, which indicates true esterase activity of albumin towards NPA. Similar results were obtained for p-nitophenyl propionate (NPP) as substrate. The rate of acetate and propionate release confirms the assumption that there is a site of true esterase activity in the albumin molecule, which is different from the site of the pseudo-esterase activity Sudlow II. The results of molecular modelling of BSA and NPA interaction make it possible to postulate that Sudlow site I is the site of true esterase activity of albumin. dc.description: The Publisher's final version can be found by following the DOI link. Open access article.

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