1.
Tjondro, Harry C., et al.
(författare)
Hyper-truncated Asn355- And Asn391-glycans modulate the activity of neutrophil granule myeloperoxidase
2021
Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 296
Tidskriftsartikel (refereegranskat) abstract
Myeloperoxidase (MPO) plays essential roles in neutrophil-mediated immunity via the generation of reactive oxidation products. Complex carbohydrates decorate MPO at discrete sites, but their functional relevance remains elusive. To this end, we have characterised the structure–biosynthesis–activity relationship of neutrophil MPO (nMPO). Mass spectrometry demonstrated that nMPO carries both characteristic under-processed and hyper-truncated glycans. Occlusion of the Asn355/Asn391-glycosylation sites and the Asn323-/Asn483-glycans, located in the MPO dimerisation zone, was found to affect the local glycan processing, thereby providing a molecular basis of the site-specific nMPO glycosylation. Native mass spectrometry, mass photometry and glycopeptide profiling revealed significant molecular complexity of diprotomeric nMPO arising from heterogeneous glycosylation, oxidation, chlorination and polypeptide truncation variants and a previously unreported low-abundance monoprotomer. Longitudinal profiling of maturing, mature, granule-separated and pathogen-stimulated neutrophils demonstrated that nMPO is dynamically expressed during granulopoiesis, unevenly distributed across granules and degranulated upon activation. We also show that proMPO-to-MPO maturation occurs during early/mid-stage granulopoiesis. While similar global MPO glycosylation was observed across conditions, the conserved Asn355-/Asn391-sites displayed elevated glycan hyper-truncation, which correlated with higher enzyme activities of MPO in distinct granule populations. Enzymatic trimming of the Asn355-/Asn391-glycans recapitulated the activity gain and showed that nMPO carrying hyper-truncated glycans at these positions exhibits increased thermal stability, polypeptide accessibility and ceruloplasmin-mediated inhibition potential relative to native nMPO. Finally, molecular modelling revealed that hyper-truncated Asn355-glycans positioned in the MPO-ceruloplasmin interface are critical for uninterrupted inhibition. Here, through an innovative and comprehensive approach, we report novel functional roles of MPO glycans, providing new insight into neutrophil-mediated immunity.
2.
Lindberg, Frida A., et al.
(författare)
SLC38A10 knockout mice display a decreased body weight and an increased risk-taking behavior in the open field test
2022
Ingår i: Frontiers in Behavioral Neuroscience. - : Frontiers Media S.A.. - 1662-5153 .- 1662-5153. ; 16
Tidskriftsartikel (refereegranskat) abstract
The solute carrier 38 family (SLC38) is a family of 11 members. The most commonsubstrate among these are alanine and glutamine, and members are present in a widerange of tissues with important functions for several biological processes, such as liverand brain function. Some of these transporters are better characterized than others and,in this paper, a behavioral characterization of SLC38A10−/− mice was carried out. Abattery of tests for general activity, emotionality, motor function, and spatial memorywere used. Among these tests, the elevated plus maze, Y-maze, marble burying, andchallenging beamwalk have not been tested on the SLC38A10−/− mice previously, whilethe open field and the rotarod tests have been performed by the International MousePhenotyping Consortium (IMPC). Unlike the results from IMPC, the results from this studyshowed that SLC38A10−/− mice spend less time in the wall zone in the open field testthan WT mice, implying that SLC38A10-deficient mice have an increased explorativebehavior, which suggests an important function of SLC38A10 in brain. The present studyalso confirmed IMPC’s data regarding rotarod performance and weight, showing thatSLC38A10−/− mice do not have an affected motor coordination impairment and havea lower body weight than both SLC38A10+/− and SLC38A10+/+ mice. These resultsimply that a complete deficiency of the SLC38A10 protein might affect body weighthomeostasis, but the underlying mechanisms needs to be studied further.
3.
Lindberg, Frida A., et al.
(författare)
SLC38A10 Deficiency in Mice Affects Plasma Levels of Threonine and Histidine in Males but Not in Females : A Preliminary Characterization Study of SLC38A10(-/-) Mice
2023
Ingår i: Genes. - : MDPI. - 2073-4425 .- 2073-4425. ; 14:4
Tidskriftsartikel (refereegranskat) abstract
Solute carriers belong to the biggest group of transporters in the human genome, but more knowledge is needed to fully understand their function and possible role as therapeutic targets. SLC38A10, a poorly characterized solute carrier, is preliminary characterized here. By using a knockout mouse model, we studied the biological effects of SLC38A10 deficiency in vivo. We performed a transcriptomic analysis of the whole brain and found seven differentially expressed genes in SLC38A10-deficient mice (Gm48159, Nr4a1, Tuba1c, Lrrc56, mt-Tp, Hbb-bt and Snord116/9). By measuring amino acids in plasma, we found lower levels of threonine and histidine in knockout males, whereas no amino acid levels were affected in females, suggesting that SLC38A10(-/-) might affect sexes differently. Using RT-qPCR, we investigated the effect of SLC38A10 deficiency on mRNA expression of other SLC38 members, Mtor and Rps6kb1 in the brain, liver, lung, muscle, and kidney, but no differences were found. Relative telomere length measurement was also taken, as a marker for cellular age, but no differences were found between the genotypes. We conclude that SLC38A10 might be important for keeping amino acid homeostasis in plasma, at least in males, but no major effects were seen on transcriptomic expression or telomere length in the whole brain.
4.
Holmér, Andreas, et al.
(författare)
The factor H variant associated with age-related macular degeneration (H384) and the non-disease associated form bind differentially to C-reactive protein, fibromodulin, DNA and necrotic cells.
2007
Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 282:15, s. 10894-10900
Tidskriftsartikel (refereegranskat) abstract
Recently, a polymorphism in the complement regulator factor H (FH) gene has been associated with age-related macular degeneration. When histidine instead of tyrosine is present at position 384 in the seventh complement control protein (CCP) domain of FH, the risk for age-related macular degeneration is increased. It was recently shown that these allotypic variants of FH, in the context of a recombinant construct corresponding to CCPs 6 - 8, recognize polyanionic structures differently, which may lead to altered regulation of the alternative pathway of complement. We show now that His-384, corresponding to the risk allele, binds C-reactive protein (CRP) poorly compared with the Tyr-384 form. We also found that C1q and phosphorylcholine do not compete with FH for binding to C-reactive protein. The interaction with extracellular matrix protein fibromodulin, which we now show to be mediated, at least in part, by CCP6 - 8 of FH, occurs via the polypeptide of fibromodulin and not through its glycosaminoglycan modifications. The Tyr-384 variant of FH bound fibromodulin better than the His-384 form. Furthermore, we find that CCP6 - 8 is able to interact with DNA and necrotic cells, but in contrast the His-384 allotype binds these ligands more strongly than the Tyr-384 variant. The variations in binding affinity of the two alleles indicate that complement activation and local inflammation in response to different targets will differ between His/His and Tyr/Tyr homozygotes.
5.
Lindberg, Frida A.
(författare)
The Biological Importance of the Amino Acid Transporter SLC38A10 : Characterization of a Knockout Mouse
2022
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
The biggest group of transporters, the solute carriers (SLCs), has more than 400 members, and about 30% of these are still orphan. In order to decipher their biological function and possible role in disease, there is a need for characterization of these. Around 25% of SLCs are estimated to have amino acids as substrates, including transporters belonging to the SLC38 family. The SLC38 members are sometimes referred to their alternative name: sodium-coupled neutral amino acid transporters (SNATs). One of these transporters, SNAT10 (or SLC38A10), has been characterized as a bidirectional transporter of glutamate, glutamine, alanine and aspartate, as well as having an efflux of serine, and is ubiquitously expressed in the body. However, its biological importance is not yet understood. The aim with this thesis was to characterize a mouse model deficient in SNAT10 protein in order to find the biological importance of this transporter. In paper I, this is done by using a series of behavioral tests, including the open field test, elevated plus maze, rotarod and Y-maze, among others. The SNAT10 knockout mouse was found to have an increased risk-taking behavior, but no motor or spatial working memory impairments. Furthermore, the knockout mouse was found to have a decreased body weight. In paper II, an additional behavioral characterization was performed by using the multivariate concentric square field™ (MCSF) test. The MCSF test is an arena with different zones associated to different behavioral traits, which generates a behavioral profile depending on where the mouse spends its time. The result from this test implies that the SNAT10 deficient mouse has a lower explorative behavior than its wild type littermates. In paper III, gene expression was studied in whole brain and some genes related to cell cycle regulation and p53 expression were found to be differentially expressed in the knockout brain. Additional gene expression was studied in kidney, liver, lung and muscle, but no changes were found. Plasma levels of histidine and threonine were altered in males, but no altered amino acid levels were found in knockout females, suggesting a possible sex-specific effect. These studies together imply that SNAT10 might be involved in processes related to risk-taking and explorative behavior in the open field and MCSF tests. SNAT10 deficiency also affected amino acid levels in plasma, indicating a disrupted amino acid homeostasis.
6.
Sukhovey, Yurij G., et al.
(författare)
Functional Conjugation of the Different Regulatory Responses to the Stress Stimuli in Healthy Human Subjects
2016
Ingår i: Open Journal of Applied Sciences. - : Scientific Research Publishing, Inc.. - 2165-3917 .- 2165-3925. ; 6, s. 489-500
Tidskriftsartikel (refereegranskat) abstract
Present article discusses the physiological mechanisms of the state employees adaptation duringactive training in temporary groups. It is suggested that adaptive mechanisms to adverse effectsmay be studied basing on the concept of functional isomorphism of the psychic and immune systems.Adaptive mechanisms were studied through the monitoring of the stress factors’ impact upon thelaw enforcement officers when training outside the places of permanent deployment. The specificpurpose of present study was to evaluate the physiological indicators of the psychic, immune andendocrine systems dynamics at different stages of adaptation of the live organism to a stressfulsituation, hoping to get better insight into possible relations between psychic and immune domains.Through monitoring of the dynamics of the endocrine and immune responses to the psychic stimuli,it was possible to correlate the stages of the stress onset to the phases of specific immune reactions.Strong correlations between the parameters characterizing activation of the psychic and immuneresponses support the hypothesis of the presence of “strong cooperation” between psychic andimmune domains. It supports earlier hypothesis that we are monitoring
7.
Deyou, Tsegaye, et al.
(författare)
Isoflavones and Rotenoids from the Leaves of Millettia oblata ssp teitensis
2017
Ingår i: Journal of Natural Products. - : American Chemical Society (ACS). - 0163-3864 .- 1520-6025. ; 80:7, s. 2060-2066
Tidskriftsartikel (refereegranskat) abstract
A new isoflavone, 8-prenylmilldrone (1), and four new rotenoids, oblarotenoids A-D (2-5), along with nine known compounds (6-14), were isolated from the CH2Cl2/CH3OH (1:1) extract of the leaves of Millettia oblata ssp. teitensis by chromatographic separation. The purified compounds were identified by NMR spectroscopic and mass spectrometric analyses, whereas the absolute configurations of the rotenoids were established on the basis of chiroptical data and in some cases by single-crystal X-ray crystallography. Maximaisoflavone J (11) and oblarotenoid C (4) showed weak activity against the human breast cancer cell line MDA-MB-231 with IC50 values of 33.3 and 93.8 mu M, respectively.
8.
Mabeyo, P. E., et al.
(författare)
Selenium Accumulating Leafy Vegetables Are a Potential Source of Functional Foods
2015
Ingår i: International Journal of Food Science. - : Hindawi Limited. - 2356-7015 .- 2314-5765. ; 2015
Tidskriftsartikel (refereegranskat) abstract
Selenium deficiency in humans has been associated with various diseases, the risks of which can be reduced through dietary supplementation. Selenium accumulating plants may provide a beneficial nutrient for avoiding such illnesses. Thus, leafy vegetables such as Amaranthus hybridus, Amaranthus sp., Cucurbita maxima, Ipomoea batatas, Solanum villosum, Solanum scabrum, and Vigna unguiculata were explored for their capabilities to accumulate selenium when grown on selenium enriched soil and for use as a potential source of selenium enriched functional foods. Their selenium contents were determined by spectrophotometry using the complex of 3,3′-diaminobenzidine hydrochloride (DABH) as a chromogen. The mean concentrations in the leaves were found to range from to μg/g dry weight (DW), with C. maxima accumulating the most selenium. In stems, the accumulated selenium content ranged from μg/g in Amaranthus sp. to μg/g DW in C. maxima and was hence significantly different (). The cancer cell line MDA-MB-231 was used in cytotoxicity assays to determine the anticancer potential of these extracts. With exception of S. scabrum and S. villosum, no cytotoxicity was detected for the selenium enriched vegetable extracts up to 100μg/mL concentration. Hence, following careful evaluation the studied vegetables may be considered as selenium enriched functional foods.
9.
Makungu, Marco, et al.
(författare)
Pterocarpans and isoflavones from the roots of Millettia micans and of Millettia dura
2016
Ingår i: Advances in Drug Discovery and Development. ; 1:1, s. 1-8
Tidskriftsartikel (refereegranskat) abstract
From the CH2Cl2/CH3OH (1:1) extract of the root bark of Millettia micans, a new pterocarpan, (6aR,11aR)-7,8,9-trimethoxy-3-hydroxypterocarpan (1), named micanspterocarpan, was isolated. Similarinvestigation of the CH2Cl2/CH3OH (1:1) extract of the root bark of Millettia dura gave a further new pterocarpan,3-O-prenylmaackiain (2) along with six known isoflavones (3-8) and a chalcone (9). All purifiedcompounds were identified by NMR and MS, and the absolute configuration of 1 was established by quantumchemical CD calculation. The isolated constituents, calopogonium isoflavone B (3) and isoerythrin A-4'-(3-methylbut-2-enyl) ether (4) showed marginal activities against the 3D7 and the Dd2 strains of Plasmodiumfalciparum (70-90% inhibition at 40 M). Maximaisoflavone B (5) and 7,2'-dimethoxy-4',5'-methylenedioxyisoflavone (7) were weakly cytotoxic (IC50 153.5 and 174.1 uM, respectively) against theMDB-MB-231 human breast cancer cell line. None of the tested compounds showed toxicity against theHEK-293 human embryonic kidney cell line at 40 uM.
10.
Nyandoro, Stephen S., 1975, et al.
(författare)
N-Cinnamoyltetraketide Derivatives from the Leaves of Toussaintia orientalis
2015
Ingår i: Journal of natural products. - : American Chemical Society (ACS). - 0163-3864 .- 1520-6025. ; 78:8, s. 2045-2050
Tidskriftsartikel (refereegranskat) abstract
Seven N-cinnamoyltetraketides (1–7), including the new Z-toussaintine E (2), toussaintine F (6), and toussaintine G (7), were isolated from the methanol extract of the leaves of Toussaintia orientalis using column chromatography and HPLC. The configurations of E-toussaintine E (1) and toussaintines A (3) and D (5) are revised based on single-crystal X-ray diffraction data from racemic crystals. Both the crude methanol extract and the isolated constituents exhibit antimycobacterial activities (MIC 83.3–107.7 μM) against the H37Rv strain of Mycobacterium tuberculosis. Compounds 1, 3, 4, and 5 are cytotoxic (ED50 15.3–105.7 μM) against the MDA-MB-231 triple negative aggressive breast cancer cell line.
