| 1. |
- Adiels, Martin, 1976, et al.
(författare)
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Role of apolipoprotein C-III overproduction in diabetic dyslipidaemia
- 2019
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Ingår i: Diabetes, obesity and metabolism. - : Wiley. - 1462-8902 .- 1463-1326. ; 21:8, s. 1861-1870
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Tidskriftsartikel (refereegranskat)abstract
- - Aims: To investigate how apolipoprotein C-III (apoC-III) metabolism is altered in subjects with type 2 diabetes, whether the perturbed plasma triglyceride concentrations in this condition are determined primarily by the secretion rate or the removal rate of apoC-III, and whether improvement of glycaemic control using the glucagon-like peptide-1 analogue liraglutide for 16 weeks modifies apoC-III dynamics. Materials and Methods: Postprandial apoC-III kinetics were assessed after a bolus injection of [5,5,5- 2 H 3 ]leucine using ultrasensitive mass spectrometry techniques. We compared apoC-III kinetics in two situations: in subjects with type 2 diabetes before and after liraglutide therapy, and in type 2 diabetic subjects with matched body mass index (BMI) non-diabetic subjects. Liver fat content, subcutaneous abdominal and intra-abdominal fat were determined using proton magnetic resonance spectroscopy. Results: Improved glycaemic control by liraglutide therapy for 16 weeks significantly reduced apoC-III secretion rate (561 ± 198 vs. 652 ± 196 mg/d, P = 0.03) and apoC-III levels (10.0 ± 3.8 vs. 11.7 ± 4.3 mg/dL, P = 0.035) in subjects with type 2 diabetes. Change in apoC-III secretion rate was significantly associated with the improvement in indices of glucose control (r = 0.67; P = 0.009) and change in triglyceride area under the curve (r = 0.59; P = 0.025). In line with this, the apoC-III secretion rate was higher in subjects with type 2 diabetes compared with BMI-matched non-diabetic subjects (676 ± 208 vs. 505 ± 174 mg/d, P = 0.042). Conclusions: The results reveal that the secretion rate of apoC-III is associated with elevation of triglyceride-rich lipoproteins in subjects with type 2 diabetes, potentially through the influence of glucose homeostasis on the production of apoC-III. © 2019 John Wiley & Sons Ltd
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| 2. |
- Björnson, Elias, 1988, et al.
(författare)
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Apolipoprotein B48 metabolism in chylomicrons and very low-density lipoproteins and its role in triglyceride transport in normo- and hypertriglyceridemic human subjects
- 2020
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Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 288:4, s. 422-438
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Tidskriftsartikel (refereegranskat)abstract
- Background Renewed interest in triglyceride-rich lipoproteins as causative agents in cardiovascular disease mandates further exploration of the integrated metabolism of chylomicrons and very low-density lipoproteins (VLDL). Methods Novel tracer techniques and an integrated multi-compartmental model were used to determine the kinetics of apoB48- and apoB100-containing particles in the chylomicron and VLDL density intervals in 15 subjects with a wide range of plasma triglyceride levels. Results Following a fat-rich meal, apoB48 appeared in the chylomicron, VLDL1 and VLDL2 fractions in all subjects. Chylomicrons cleared rapidly from the circulation but apoB48-containing VLDL accumulated, and over the day were 3-fold higher in those with high versus low plasma triglyceride. ApoB48-containing particles were secreted directly into both the chylomicron and VLDL fractions at rates that were similar across the plasma triglyceride range studied. During fat absorption, whilst most triglyceride entered the circulation in chylomicrons, the majority of apoB48 particles were secreted into the VLDL density range. Conclusion The intestine secretes apoB48-containing particles not only as chylomicrons but also directly into the VLDL1 and VLDL2 density ranges both in the basal state and during dietary lipid absorption. Over the day, apoB48-containing particles appear to comprise about 20-25% of circulating VLDL and, especially in those with elevated triglycerides, form part of a slowly cleared 'remnant' particle population, thereby potentially increasing CHD risk. These findings provide a metabolic understanding of the potential consequences for increased CHD risk when slowed lipolysis leads to the accumulation of remnants, especially in individuals with hypertriglyceridemia.
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| 3. |
- Björnson, Elias, 1988, et al.
(författare)
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Investigation of human apoB48 metabolism using a new, integrated non-steady-state model of apoB48 and apoB100 kinetics
- 2019
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Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 285:5, s. 562-577
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundTriglyceride-rich lipoproteins and their remnants have emerged as major risk factors for cardiovascular disease. New experimental approaches are required that permit simultaneous investigation of the dynamics of chylomicrons (CM) and apoB48 metabolism and of apoB100 in very low-density lipoproteins (VLDL). MethodsMass spectrometric techniques were used to determine the masses and tracer enrichments of apoB48 in the CM, VLDL1 and VLDL2 density intervals. An integrated non-steady-state multicompartmental model was constructed to describe the metabolism of apoB48- and apoB100-containing lipoproteins following a fat-rich meal, as well as during prolonged fasting. ResultsThe kinetic model described the metabolism of apoB48 in CM, VLDL1 and VLDL2. It predicted a low level of basal apoB48 secretion and, during fat absorption, an increment in apoB48 release into not only CM but also directly into VLDL1 and VLDL2. ApoB48 particles with a long residence time were present in VLDL, and in subjects with high plasma triglycerides, these lipoproteins contributed to apoB48 measured during fasting conditions. Basal apoB48 secretion was about 50mgday(-1), and the increment during absorption was about 230mgday(-1). The fractional catabolic rates for apoB48 in VLDL1 and VLDL2 were substantially lower than for apoB48 in CM. DiscussionThis novel non-steady-state model integrates the metabolic properties of both apoB100 and apoB48 and the kinetics of triglyceride. The model is physiologically relevant and provides insight not only into apoB48 release in the basal and postabsorptive states but also into the contribution of the intestine to VLDL pool size and kinetics.
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| 4. |
- Taskinen, Marja-Riitta, et al.
(författare)
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Contribution of intestinal triglyceride-rich lipoproteins to residual atherosclerotic cardiovascular disease risk in individuals with type 2 diabetes on statin therapy
- 2023
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Ingår i: DIABETOLOGIA. - 0012-186X .- 1432-0428. ; 66:12, s. 2307-2319
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Tidskriftsartikel (refereegranskat)abstract
- Aims/hypothesis: This study explored the hypothesis that significant abnormalities in the metabolism of intestinally derived lipoproteins are present in individuals with type 2 diabetes on statin therapy. These abnormalities may contribute to residual CVD risk.Methods: To investigate the kinetics of ApoB-48- and ApoB-100-containing lipoproteins, we performed a secondary analysis of 11 overweight/obese individuals with type 2 diabetes who were treated with lifestyle counselling and on a stable dose of metformin who were from an earlier clinical study, and compared these with 11 control participants frequency-matched for age, BMI and sex. Participants in both groups were on a similar statin regimen during the study. Stable isotope tracers were used to determine the kinetics of the following in response to a standard fat-rich meal: (1) apolipoprotein (Apo)B-48 in chylomicrons and VLDL; (2) ApoB-100 in VLDL, intermediate-density lipoprotein (IDL) and LDL; and (3) triglyceride (TG) in VLDL.Results: The fasting lipid profile did not differ significantly between the two groups. Compared with control participants, in individuals with type 2 diabetes, chylomicron TG and ApoB-48 levels exhibited an approximately twofold higher response to the fat-rich meal, and a twofold higher increment was observed in ApoB-48 particles in the VLDL1 and VLDL2 density ranges (all p < 0.05). Again comparing control participants with individuals with type 2 diabetes, in the latter, total ApoB-48 production was 25% higher (556 +/- 57 vs 446 +/- 57 mg/day; p < 0.001), conversion (fractional transfer rate) of chylomicrons to VLDL was around 40% lower (35 +/- 25 vs 82 +/- 58 pools/day; p=0.034) and direct clearance of chylomicrons was 5.6-fold higher (5.6 +/- 2.2 vs 1.0 +/- 1.8 pools/day; p < 0.001). During the postprandial period, ApoB-48 particles accounted for a higher proportion of total VLDL in individuals with type 2 diabetes (44%) compared with control participants (25%), and these ApoB-48 VLDL particles exhibited a fivefold longer residence time in the circulation (p < 0.01). No between-group differences were seen in the kinetics of ApoB-100 and TG in VLDL, or in LDL ApoB-100 production, pool size and clearance rate. As compared with control participants, the IDL ApoB-100 pool in individuals with type 2 diabetes was higher due to increased conversion from VLDL2.Conclusions/interpretation: Abnormalities in the metabolism of intestinally derived ApoB-48-containing lipoproteins in individuals with type 2 diabetes on statins may help to explain the residual risk of CVD and may be suitable targets for interventions.
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| 5. |
- Taskinen, M. R., et al.
(författare)
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Role of endogenous incretins in the regulation of postprandial lipoprotein metabolism
- 2022
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Ingår i: European Journal of Endocrinology. - : Oxford University Press (OUP). - 0804-4643 .- 1479-683X. ; 187:1, s. 75-84
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Incretins are known to influence lipid metabolism in the intestine when administered as pharmacologic agents. The aggregate influence of endogenous incretins on chylomicron production and clearance is less clear, particularly in light of opposing effects of co-secreted hormones. Here, we tested the hypothesis that physiological levels of incretins may impact on production or clearances rates of chylomicrons and VLDL. Design and methods: A group of 22 overweight/obese men was studied to determine associations between plasma levels of glucagon-like peptides 1 and 2 (GLP-1 and GLP-2) and glucose-dependent insulinotropic polypeptide (GIP) after a fat-rich meal and the production and clearance rates of apoB48- and apoB100-containing triglyceride-rich lipoproteins. Subjects were stratified by above- and below-median incretin response (area under the curve). Results: Stratification yielded subgroups that differed about two-fold in incretin response. There were neither differences in apoB48 production rates in chylomicrons or VLDL fractions nor in apoB100 or triglyceride kinetics in VLDL between men with above- vs below-median incretin responses. The men with above-median GLP-1 and GLP-2 responses exhibited higher postprandial plasma and chylomicron triglyceride levels, but this could not be related to altered kinetic parameters. No differences were found between incretin response subgroups and particle clearance rates. Conclusion: We found no evidence for a regulatory effect of endogenous incretins on contemporaneous chylomicron or VLDL metabolism following a standardised fat-rich meal. The actions of incretins at pharmacological doses may not be reflected at physiological levels of these hormones.
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| 6. |
- Zettergren, Anna, 1978, et al.
(författare)
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Proteomic analyses of limbic regions in neonatal male, female and androgen receptor knockout mice
- 2017
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Ingår i: Bmc Neuroscience. - : Springer Science and Business Media LLC. - 1471-2202. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- Background: It is well-established that organizational effects of sex steroids during early development are fundamental for sex-typical displays of, for example, mating and aggressive behaviors in rodents and other species. Male and female brains are known to differ with respect to neuronal morphology in particular regions of the brain, including the number and size of neurons, and the density and length of dendrites in nuclei of hypothalamus and amygdala. The aim of the present study was to use global proteomics to identify proteins differentially expressed in hypothalamus/amygdala during early development (postnatal day 8) of male, female and conditional androgen receptor knockout (AR(NesDel)) male mice, lacking androgen receptors specifically in the brain. Furthermore, verification of selected sexually dimorphic proteins was performed using targeted proteomics. Results: Our proteomic approach, iTRAQ, allowed us to investigate expression differences in the 2998 most abundantly expressed proteins in our dissected tissues. Approximately 170 proteins differed between the sexes, and 38 proteins between AR(NesDel) and control males (p < 0.05). In line with previous explorative studies of sexually dimorphic gene expression we mainly detected subtle protein expression differences (fold changes < 1.3). The protein MARCKS (myristoylated alanine rich C kinase substrate), having the largest fold change of the proteins selected from the iTRAQ analyses and of known importance for synaptic transmission and dendritic branching, was confirmed by targeted proteomics as differentially expressed between the sexes. Conclusions: Overall, our results provide solid evidence that a large number of proteins show sex differences in their brain expression and could potentially be involved in brain sexual differentiation. Furthermore, our finding of a sexually dimorphic expression of MARCKS in the brain during development warrants further investigation on the involvement in sexual differentiation of this protein.
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| 7. |
- Bergemalm, Daniel, 1977-, et al.
(författare)
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Platelet proteome and function in X-linked thrombocytopenia with thalassemia and in silico comparisons with gray platelet syndrome
- 2021
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Ingår i: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 1592-8721 .- 0390-6078. ; 106:11
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Tidskriftsartikel (refereegranskat)abstract
- In X-linked thrombocytopenia with thalassemia (XLTT; OMIM 314050), caused by the mutation p.R216Q in exon 4 of the GATA1 gene, male hemizygous patients display macrothrombocytopenia, bleeding diathesis and a β-thalassemia trait. Herein, we describe findings in two unrelated Swedish XLTT families with a bleeding tendency exceeding what is expected from the thrombocytopenia. Blood tests revealed low P-PAI-1 and P-factor 5, and elevated S-thrombopoietin levels. Transmission electron microscopy showed diminished numbers of platelet α- and dense granules. The proteomes of isolated blood platelets from 5 male XLTT patients, compared to 5 gender- and age matched controls, were explored. Quantitative mass spectrometry showed alterations of 83 proteins (fold change ≥±1.2, q< .05). Of 46 downregulated proteins, 39 were previously reported to be associated with platelet granules. Reduced protein levels of PTGS1 and SLC35D3 were validated in megakaryocytes of XLTT bone marrow biopsies by immunohistochemistry. Platelet function testing by flow cytometry revealed low dense- and α-granule release and fibrinogen binding in response to ligation of receptors for ADP, the thrombin receptor PAR4 and the collagen receptor GPVI. Significant reductions of a number of α-granule proteins overlapped with a previous platelet proteomics investigation in the inherited macrothrombocytopenia gray platelet syndrome (GPS). In contrast, Ca2+ transporter proteins that facilitate dense granule release were downregulated in XLTT but upregulated in GPS. Ingenuity Pathway Analysis showed altered Coagulation System and Protein Ubiquitination pathways in the XLTT platelets. Collectively, the results revealed protein and functional alterations affecting platelet α- and dense granules in XLTT, probably contributing to bleeding.
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| 8. |
- Chursa, Urszula, et al.
(författare)
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Overexpression of protein kinase STK25 in mice exacerbates ectopic lipid accumulation, mitochondrial dysfunction and insulin resistance in skeletal muscle.
- 2017
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 60:3, s. 553-567
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the molecular networks controlling ectopic lipid deposition and insulin responsiveness in skeletal muscle is essential for developing new strategies to treat type 2 diabetes. We recently identified serine/threonine protein kinase 25 (STK25) as a critical regulator of liver steatosis, hepatic lipid metabolism and whole body glucose and insulin homeostasis. Here, we assessed the role of STK25 in control of ectopic fat storage and insulin responsiveness in skeletal muscle.Skeletal muscle morphology was studied by histological examination, exercise performance and insulin sensitivity were assessed by treadmill running and euglycaemic-hyperinsulinaemic clamp, respectively, and muscle lipid metabolism was analysed by ex vivo assays in Stk25 transgenic and wild-type mice fed a high-fat diet. Lipid accumulation and mitochondrial function were also studied in rodent myoblasts overexpressing STK25. Global quantitative phosphoproteomics was performed in skeletal muscle of Stk25 transgenic and wild-type mice fed a high-fat diet to identify potential downstream mediators of STK25 action.We found that overexpression of STK25 in transgenic mice fed a high-fat diet increases intramyocellular lipid accumulation, impairs skeletal muscle mitochondrial function and sarcomeric ultrastructure, and induces perimysial and endomysial fibrosis, thereby reducing endurance exercise capacity and muscle insulin sensitivity. Furthermore, we observed enhanced lipid accumulation and impaired mitochondrial function in rodent myoblasts overexpressing STK25, demonstrating an autonomous action for STK25 within cells. Global phosphoproteomic analysis revealed alterations in the total abundance and phosphorylation status of different target proteins located predominantly to mitochondria and sarcomeric contractile elements in Stk25 transgenic vs wild-type muscle, respectively, providing a possible molecular mechanism for the observed phenotype.STK25 emerges as a new regulator of the complex interplay between lipid storage, mitochondrial energetics and insulin action in skeletal muscle, highlighting the potential of STK25 antagonists for type 2 diabetes treatment.
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| 9. |
- Najar, Deman Hadi, et al.
(författare)
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Pharmacokinetic Properties of the Nephrotoxin Orellanine in Rats
- 2018
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Ingår i: Toxins. - : MDPI AG. - 2072-6651. ; 10:8
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Tidskriftsartikel (refereegranskat)abstract
- Orellanine is a nephrotoxin found in mushrooms of the Cortinarius family. Accidental intake of this substance may cause renal failure. Orellanine is specific for proximal tubular cells and could, therefore, potentially be used as treatment for metastatic renal cancer, which originates from these cells. However, more information is needed about the distribution and elimination of orellanine from the body to understand its potential use for therapy. In this study, 5 mg/kg orellanine (unlabeled and H-3-labeled) was injected intravenously in rats (Wistar and Sprague Dawley). Distribution was measured (Wistar rats, n = 10, n = 12) using radioluminography and the highest amount of orellanine was found in the kidney cortex and bladder at all time-points investigated. The pharmacokinetic properties of orellanine were investigated using LC-MS/MS and -scintillation to measure the amount of orellanine in plasma. Three groups of rats were investigated: control rats with intact kidneys (n = 10) and two groups with bilateral renal artery ligation (n = 7) where animals in one of these groups were treated with peritoneal dialysis (n = 8). Using LC-MS/MS, the half-life of orellanine was found to be 109 +/- 6 min in the controls. In the groups with ligated renal arteries, orellanine had a half-life of 756 +/- 98 min without and 238 +/- 28 min with dialysis. Thus, orellanine was almost exclusively eliminated by glomerular filtration as well as by peritoneal dialysis.
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| 10. |
- Norén, Åsa, et al.
(författare)
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Liver Graft Proteomics Reveals Potential Incipient Mechanisms behind Early Renal Dysfunction after Liver Transplantation
- 2022
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1422-0067. ; 23:19
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Tidskriftsartikel (refereegranskat)abstract
- Acute kidney injury (AKI) is frequent after liver transplantation (LT) and correlates with later development of chronic kidney disease. Its etiology is multifactorial and combines pre-, intra-, and postoperative factors. Additionally, the liver graft itself seems an important element in the development of AKI, yet the detailed mechanisms remain unclear. We hypothesized that grafts of LT recipients developing significant early AKI may show distinct proteomic alterations, and we set out to identify proteome differences between LT recipients developing moderate or severe AKI (n = 7) and LT recipients without early renal injury (n = 7). Liver biopsies obtained one hour after reperfusion were assessed histologically and using quantitative proteomics. Several cytokines and serum amyloid A2 (SAA2) were analyzed in serum samples obtained preoperatively, 2-4 h, and 20-24 h after graft reperfusion, respectively. LT induced mild histological alterations without significant differences between groups but uniformly altered liver function tests peaking on postoperative day 1, with a trend towards more severe alterations in patients developing AKI. Global quantitative proteomic analysis revealed 136 proteins differing significantly in their expression levels (p < 0.05, FC 20%): 80 proteins had higher and 56 had lower levels in the AKI group. Most of these proteins were related to immune and inflammatory responses, host defense, and neutrophil degranulation. No differences between the studied pro- and anti-inflammatory cytokines or SAA2 between groups were found at any moment. Our results suggest that grafts of LT patients who develop early AKI reveal a distinct proteome dominated by an early yet prominent activation of the innate immunity. These findings support the hypothesis that AKI after LT may be favored by certain graft characteristics.
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| 11. |
- Oras, Jonatan, 1978, et al.
(författare)
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Anaesthetic-induced cardioprotection in an experimental model of the Takotsubo syndrome - isoflurane vs. propofol.
- 2017
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Ingår i: Acta anaesthesiologica Scandinavica. - : Wiley. - 1399-6576 .- 0001-5172. ; 61:3, s. 309-321
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Tidskriftsartikel (refereegranskat)abstract
- Takotsubo syndrome (TS) is an acute cardiac condition with a substantial mortality for which no specific treatment is available. We have previously shown that isoflurane attenuates the development of left ventricular (LV) dysfunction in an experimental TS-model. We compared the effects of equi-anaesthetic doses of isoflurane, propofol and ketamine+midazolam on haemodynamics, global and regional LV systolic function and the activation of intracellular metabolic pathways in experimental TS. We hypothesized that cardioprotection in experimental TS is specific for isoflurane.Forty-five rats were randomized to isoflurane (0.6 MAC, n=15), propofol (bolus 200mg/kg+360mg/kg/h, n=15) or ketamine (100mg/kg)+midazolam (10mg/kg, n=15) anaesthesia. Arterial pressure, heart rate and body temperature were continuously measured and arterial blood gas analysis was performed intermittently. TS was induced by intraperitoneal injection of isoprenaline, 50mg/kg. LV echocardiography was performed 90min after isoprenaline injection. Apical cardiac tissue was analysed by global discovery proteomics and pathway analysis.Isoprenaline-induced changes in arterial blood pressure, heart rate or body temperature did not differ between groups. LV ejection fraction was higher and extent of LV akinesia was lower with isoflurane, when compared with the propofol and the ketamine+midazolam groups. In this TS-model, the proteomic analysis revealed an up-regulation of pathways involved in inflammation, coagulation, endocytosis and lipid metabolism. This up-regulation was clearly attenuated with isoflurane compared to propofol.In an experimental model of TS, isoflurane, but not propofol, exerts a cardioprotective effect. The proteomic analysis suggests that inflammation might be involved in pathogenesis of TS.
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| 12. |
- Alfredsson, Johannes, et al.
(författare)
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Isobaric labeling-based quantitative proteomics of FACS-purified immune cells and epithelial cells from the intestine of Crohn's disease patients reveals proteome changes of potential importance in disease pathogenesis.
- 2023
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Ingår i: Proteomics. - : Wiley. - 1615-9861 .- 1615-9853. ; 23:5
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Tidskriftsartikel (refereegranskat)abstract
- Crohn's disease (CD) is a chronic condition characterized by recurrent flares of inflammation in the gastrointestinal tract. Disease etiology is poorly understood and is characterized by dysregulated immune activation that progressively destroys intestinal tissue. Key cellular compartments in disease pathogenesis are the intestinal epithelial layer and its underlying lamina propria. While the epithelium contains predominantly epithelial cells, the lamina propria is enriched in immune cells. Deciphering proteome changes in different cell populations is important to understand CD pathogenesis. Here, using isobaric labeling-based quantitative proteomics, we perform an exploratory study to analyze in-depth proteome changes in epithelial cells, immune cells and stromal cells in CD patients compared to controls using cells purified by FACS. Our study revealed increased proteins associated with neutrophil degranulation and mitochondrial metabolism in immune cells of CD intestinal mucosa. We also found upregulation of proteins involved in glycosylation and secretory pathways in epithelial cells of CD patients, while proteins involved in mitochondrial metabolism were reduced. The distinct alterations in protein levels in immune- versus epithelial cells underscores the utility of proteome analysis of defined cell types. Moreover, our workflow allowing concomitant assessment of cell-type specific changes on an individual basis enables deeper insight into disease pathogenesis.
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| 13. |
- Bachar-Wikstrom, Etty, et al.
(författare)
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Identification of Novel Glycans in the Mucus Layer of Shark and Skate Skin
- 2023
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Ingår i: INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES. - 1661-6596 .- 1422-0067. ; 24:18
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Tidskriftsartikel (refereegranskat)abstract
- The mucus layer covering the skin of fish has several roles, including protection against pathogens and mechanical damage. While the mucus layers of various bony fish species have been investigated, the composition and glycan profiles of shark skin mucus remain relatively unexplored. In this pilot study, we aimed to explore the structure and composition of shark skin mucus through histological analysis and glycan profiling. Histological examination of skin samples from Atlantic spiny dogfish (Squalus acanthias) sharks and chain catsharks (Scyliorhinus retifer) revealed distinct mucin-producing cells and a mucus layer, indicating the presence of a functional mucus layer similar to bony fish mucus albeit thinner. Glycan profiling using liquid chromatography-electrospray ionization tandem mass spectrometry unveiled a diverse repertoire of mostly O-glycans in the mucus of the two sharks as well as little skate (Leucoraja erinacea). Elasmobranch glycans differ significantly from bony fish, especially in being more sulfated, and some bear resemblance to human glycans, such as gastric mucin O-glycans and H blood group-type glycans. This study contributes to the concept of shark skin having unique properties and provides a foundation for further research into the functional roles and potential biomedical implications of shark skin mucus glycans.
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| 14. |
- Banerjee, Debashish, et al.
(författare)
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Characterization of Decellularized Implants for Extracellular Matrix Integrity and Immune Response Elicitation
- 2022
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Ingår i: Tissue Engineering Part A. - : Mary Ann Liebert Inc. - 1937-3341 .- 1937-335X. ; 28:13-14, s. 621-639
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Tidskriftsartikel (refereegranskat)abstract
- Biological scaffold is a popular choice for the preparation of tissue-engineered organs and has the potential to address donor shortages in clinics. However, biological scaffolds prepared by physical or chemical agents cause damage to the extracellular matrix (ECM) by potentially inducing immune responses after implantation. The current study explores the fate of the decellularized (DC) scaffolds using a cocktail of chemicals following implantation without using immunosuppressants. Using the syngeneic (Lewis male-Lewis female) and allogeneic (Brown Norway male-Lewis female) models and different tissue routes (subcutaneous vs. omentum) for implantation, we applied in-depth quantitative proteomics, genomics along with histology and quantitative image analysis tools to comprehensively describe and compare the proteins following DC and postimplantation. Our data helped to identify any alteration postdecullarization as well implantation. We could also monitor route-specific modulation of the ECM and regulation of the immune responses (macrophage and T cells) following implantation. The current approach opens up the possibility to monitor the fate of biological scaffolds in terms of the ECM and immune response against the implants. In addition, the identification of different routes helped us to identify differential immune responses against the implants. This study opens up the potential to identify the changes associated with chemical DC both pre- and postimplantation, which could further help to promote research in this direction. Impact StatementThe development of a biological scaffold helps in the preparation of a functional organ in the clinics. In the current study, we develop a strategy for chemical decellularization and explored two different routes to understand the differential responses elicited postimplantation. The use of sensitive protein and genomic tools to study the changes creates a favorable environment for similar efforts to develop and characterize biological scaffolds before further trials in the clinics. The current study, which was carried out without any immunosuppressive agents, could help to establish (a) appropriate chemical strategies for preparing biological scaffolds as well as (b) identify putative implantable routes to circumvent any adverse immune reactions, which will ultimately decide the outcome for acceptance or rejection of the scaffold/implant.
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| 15. |
- Bergwall, Lovisa, et al.
(författare)
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Amplification of the Melanocortin-1 Receptor in Nephrotic Syndrome Identifies a Target for Podocyte Cytoskeleton Stabilization
- 2018
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- The melanocortin-1 receptor (MC1R) in podocytes has been suggested as the mediator of the ACTH renoprotective effect in patients with nephrotic syndrome with the mechanism of action beeing stabilization of the podocyte actin cytoskeleton. To understand how melanocortin receptors are regulated in nephrotic syndrome and how they are involved in restoration of filtration barrier function, melanocortin receptor expression was evaluated in patients and a rat model of nephrotic syndrome in combination with cell culture analysis. Phosphoproteomics was applied and identified MC1R pathways confirmed using biochemical analysis. We found that glomerular MC1R expression was increased in nephrotic syndrome, both in humans and in a rat model. A MC1R agonist protected podocytes from protamine sulfate induced stress fiber loss with the top ranked phoshoproteomic MC1R activated pathway beeing actin cytoskeleton signaling. Actin stabilization through the MC1R consisted of ERK1/2 dependent phosphorylation and inactivation of EGFR signaling with stabilization of synaptopodin and stressfibers in podocytes. These results further explain how patients with nephrotic syndrome show responsiveness to MC1R receptor activation by decreasing EGFR signaling and as a consequence restore filtration barrier function by stabilizing the podocyte actin cytoskeleton.
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| 16. |
- Bobbio, Emanuele, et al.
(författare)
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Clinical Diagnosis and Subtyping of Cardiac Amyloidosis by Mass Spectrometry.
- 2020
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Ingår i: The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation. - : Elsevier BV. - 1557-3117. ; 39:4S
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Tidskriftsartikel (refereegranskat)abstract
- Medical treatment for cardiac amyloidosis (CA) is evolving rapidly. Heart transplantation can be a valid option when followed by transplantation of bone marrow or liver, dependent on the type and origin of the amyloid protein. Thus, accurate typing of amyloidosis has implications for treatment, prognosis, and genetic counseling. Although non-invasive diagnostic techniques can type CA, endomyocardial biopsy (EMB) may be needed in the case of equivocal imaging findings or discordant data. We aimed to define the role of mass spectrometry (MS) for diagnosis and subtyping of CA.Nineteen previously diagnosed CA cases, who underwent EMB at Sahlgrenska University Hospital (SU), Gothenburg, between the beginning 1990s and 2016, were selected. MS analysis, modified from was conducted on duplicate samples from myocardial tissue for each case included.1 Clinical features and diagnoses were used as gold standard and compared to the MS findings.Clinical diagnosis and the MS analysis agreed in 14 cases (73.7 %); in 3/19 (15.8 %) diagnosis was unclear or discordant (Fig.1). MS analysis revealed that transthyretin (TTR) amyloidosis was the most abundant amyloid protein in the samples examined (9/19; 47.3 %), whereas the AA subtype only occurred in 1 case (5.2 %). The AL κ type amyloidosis occurred in 3 cases (15.8 %), and AL λ type in six cases (31.6 %). These results strongly correlated with the clinical features in all patients. Clinical diagnosis could not be retrieved from the medical records in 2 cases (10.4 %). Additional 20 patients with clinical CA are presently under study.MS analysis of a small amount of endomyocardial tissue can be used to subtype CA with a high diagnostic validity. The method differentiated between TTR, SAA and Ig light chain amyloidosis. AL κ and AL λ identities correlated to those found in serum and urine electrophoreses. MS can therefore be of use to subtype CA for cases in which clinical findings are inconclusive. 1) Brambilla F et al. Blood. 2012 Feb 23;119(8):1844-7.
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| 17. |
- Brogren, Helén, 1977, et al.
(författare)
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Heterogeneous glycosylation patterns of human PAI-1 may reveal its cellular origin.
- 2008
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Ingår i: Thrombosis research. - : Elsevier BV. - 0049-3848. ; 122:2, s. 271-81
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Tidskriftsartikel (refereegranskat)abstract
- The main inhibitor of intravascular fibrinolysis is plasminogen activator inhibitor 1 (PAI-1) which binds to and irreversibly inhibits tissue plasminogen activator (tPA). PAI-1 is present in blood, both in platelets and in plasma, and PAI-1 levels are associated with risk of atherothrombosis. Several tissues express PAI-1 but the source of plasma PAI-1 is not known. We recently found that platelets can de novo synthesize PAI-1 and the amount synthesized in vitro in 24 hours is 35-fold higher than required to maintain normal plasma levels. Recombinant human PAI-1 expressed in different cell types or secreted naturally by human cell lines, exhibit heterogeneous glycosylation patterns. The aim of this study was to investigate the hypothesis that platelets might be the source of plasma PAI-1 and that the cellular source of PAI-1 can be determined by its tissue-specific glycosylation pattern. PAI-1 was isolated from platelets, macrophages, endothelial cells, adipose tissue, as well as plasma from lean and obese subjects. The glycosylation was analyzed by nanoLC-MS/MS. PAI-1 isolated from cell lysates and conditioned media from macrophages, endothelial cells, and adipose tissue expressed heterogeneous glycosylation patterns. By contrast, no glycans were detected on PAI-1 isolated from plasma or platelets from healthy lean individuals. Hence, our data suggest that platelets may be the main source of plasma PAI-1 in lean individuals. Interestingly, plasma PAI-1 from obese subjects had a glycan composition similar to that of adipose tissue suggesting that obese subjects with elevated PAI-1 levels may have a major contribution from other tissues.
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| 18. |
- Brown, Rosemary, 1990, et al.
(författare)
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Quantifying absolute gene expression profiles reveals distinct regulation of central carbon metabolism genes in yeast
- 2021
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Ingår i: eLife. - 2050-084X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- In addition to controlled expression of genes by specific regulatory circuits, the abundance of proteins and transcripts can also be influenced by physiological states of the cell such as growth rate and metabolism. Here we examine the control of gene expression by growth rate and metabolism, by analyzing a multi-omics dataset consisting of absolute-quantitative abundances of the transcriptome, proteome, and amino acids in 22 steady-state yeast cultures. We find that transcription and translation are coordinately controlled by the cell growth rate via RNA polymerase II and ribosome abundance, but they are independently controlled by nitrogen metabolism via amino acid and nucleotide availabilities. Genes in central carbon metabolism, however, are distinctly regulated and do not respond to the cell growth rate or nitrogen metabolism as all other genes. Understanding these effects allows the confounding factors of growth rate and metabolism to be accounted for in gene expression profiling studies.
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| 19. |
- Buvall, Lisa, 1976, et al.
(författare)
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Orellanine specifically targets renal clear cell carcinoma
- 2017
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Ingår i: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 8:53, s. 91085-91098
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Tidskriftsartikel (refereegranskat)abstract
- Renal cell carcinoma (RCC), arising from the proximal tubule in the kidney, accounts for approximately 85% of kidney cancers and causes over 140,000 annual deaths worldwide. In the last decade, several new therapies have been identified for treatment of metastatic RCC. Although these therapies increase survival time compared to standard care, none of them has curative properties. The nephrotoxin orellanine specifically targets proximal tubular epithelial cells, leaving other organs unaffected. We therefore hypothesized that the selective toxicity of orellanine extends to clear cell RCC (ccRCC) cells since they emanate from proximal tubular cells. Orellanine would thus target both primary and metastatic ccRCC in vitro and in vivo. We found that orellanine induces dose-dependent cell death in proximal tubular cells and in all ccRCC cells tested, both primary and cell lines, with no toxicity detected in control cells. The toxic action of orellanine involve decreased protein synthesis, disrupted cell metabolism and induction of apoptosis. In nude rats carrying human ccRCC xenografts, brief orellanine treatment eliminated more than 90% of viable tumor mass compared to control rats. This identifies orellanine as a potential treatment concept for ccRCC patients on dialysis, due to its unique selective toxicity towards ccRCC.
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| 20. |
- Cansby, Emmelie, 1984, et al.
(författare)
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Protein kinase MST3 modulates lipid homeostasis in hepatocytes and correlates with nonalcoholic steatohepatitis in humans.
- 2019
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Ingår i: FASEB journal : official publication of the Federation of American Societies for Experimental Biology. - 1530-6860. ; 33:9, s. 9974-9989
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Tidskriftsartikel (refereegranskat)abstract
- Ectopic lipid storage in the liver is considered the main risk factor for nonalcoholic steatohepatitis (NASH). Understanding the molecular networks controlling hepatocellular lipid deposition is therefore essential for developing new strategies to effectively prevent and treat this complex disease. Here, we describe a new regulator of lipid partitioning in human hepatocytes: mammalian sterile 20-like (MST) 3. We found that MST3 protein coats lipid droplets in mouse and human liver cells. Knockdown of MST3 attenuated lipid accumulation in human hepatocytes by stimulating β-oxidation and triacylglycerol secretion while inhibiting fatty acid influx and lipid synthesis. We also observed that lipogenic gene expression and acetyl-coenzyme A carboxylase protein abundance were reduced in MST3-deficient hepatocytes, providing insight into the molecular mechanisms underlying the decreased lipid storage. Furthermore, MST3 expression was positively correlated with key features of NASH (i.e., hepatic lipid content, lobular inflammation, and hepatocellular ballooning) in human liver biopsies. In summary, our results reveal a role of MST3 in controlling the dynamic metabolic balance of liver lipid catabolism vs. lipid anabolism. Our findings highlight MST3 as a potential drug target for the prevention and treatment of NASH and related complex metabolic diseases.
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| 21. |
- Cansby, Emmelie, 1984, et al.
(författare)
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Silencing of STE20-type kinase STK25 in human aortic endothelial and smooth muscle cells is atheroprotective
- 2022
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 5, s. 1-14
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies highlight the importance of lipotoxic damage in aortic cells as the major pathogenetic contributor to atherosclerotic disease. Since the STE20-type kinase STK25 has been shown to exacerbate ectopic lipid storage and associated cell injury in several metabolic organs, we here investigate its role in the main cell types of vasculature. We depleted STK25 by small interfering RNA in human aortic endothelial and smooth muscle cells exposed to oleic acid and oxidized LDL. In both cell types, the silencing of STK25 reduces lipid accumulation and suppresses activation of inflammatory and fibrotic pathways as well as lowering oxidative and endoplasmic reticulum stress. Notably, in smooth muscle cells, STK25 inactivation hinders the shift from a contractile to a synthetic phenotype. Together, we provide several lines of evidence that antagonizing STK25 signaling in human aortic endothelial and smooth muscle cells is atheroprotective, highlighting this kinase as a new potential therapeutic target for atherosclerotic disease.
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| 22. |
- Cvjetkovic, Aleksander, et al.
(författare)
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Detailed Analysis of Protein Topology of Extracellular Vesicles–Evidence of Unconventional Membrane Protein Orientation
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Extracellular vesicles (EVs) are important mediators of intercellular communication that change the recipient cell by shuttling lipids, RNA, or protein cargo between cells. Here, we investigate the topology of the protein cargo found in EVs, as this topology can fundamentally influence the biological effects of EVs. A multiple proteomics approach, combining proteinase treatment and biotin tagging, shows that many proteins of cytosolic origin are localized on the surface of EVs. A detailed analysis of the EV proteome at the peptide level revealed that a number of EV membrane proteins are present in a topologically reversed orientation compared to what is annotated. Two examples of such proteins, SCAMP3 and STX4, were confirmed to have a reversed topology. This reversed typology was determined using flow cytometry and fluorescent microscopy with antibodies directed toward their cytoplasmic epitopes. These results describe a novel workflow to define the EV proteome and the orientation of each protein, including membrane protein topology. These data are fundamentally important to understanding the EV proteome and required to fully explain EV biogenesis as well as biological function in recipient cells.
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| 23. |
- Dawe, H., et al.
(författare)
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D-methionine interferes with non-typeable Haemophilus influenzae peptidoglycan synthesis during growth and biofilm formation
- 2017
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Ingår i: Microbiology-Sgm. - : Microbiology Society. - 1350-0872. ; 163:7, s. 1093-1104
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Tidskriftsartikel (refereegranskat)abstract
- Non-typeable Haemophilus influenzae (NTHi) is an opportunistic pathogen that plays a major role in a number of respiratory tract infections, including otitis media, cystic fibrosis and chronic obstructive pulmonary disease. Biofilm formation has been implicated in both NTHi colonization and disease, and is responsible for the increased tolerance of this pathogen towards antibiotic treatment. Targeting metabolic pathways that are important in NTHi biofilm formation represents a potential strategy to combat this antibiotic recalcitrance. A previous investigation demonstrated increased expression of a putative D-methionine uptake protein following exposure of NTHi biofilms to the ubiquitous signalling molecule, nitric oxide. We therefore hypothesized that treatment with exogenous D-methionine would impact on NTHi biofilm formation and increase antibiotic sensitivity. Treatment of NTHi during the process of biofilm formation resulted in a reduction in biofilm viability, increased biomass, changes in the overall biofilm architecture and the adoption of an amorphous cellular morphology. Quantitative proteomic analyses identified 124 proteins that were differentially expressed following D-methionine treatment, of which 51 (41 %) were involved in metabolic and transport processes. Nine proteins involved in peptidoglycan synthesis and cell division showed significantly increased expression. Furthermore, D-methionine treatment augmented the efficacy of azithromycin treatment and highlighted the potential of D-methionine as an adjunctive therapeutic approach for NTHi biofilm-associated infections.
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| 24. |
- Fabrik, Ivo, et al.
(författare)
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Lung macrophages utilize unique cathepsin K-dependent phagosomal machinery to degrade intracellular collagen
- 2023
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Ingår i: Life Science Alliance (LSA). - : Life Science Alliance, LLC. - 2575-1077. ; 6:4
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Tidskriftsartikel (refereegranskat)abstract
- Resident tissue macrophages are organ-specialized phagocytes responsible for the maintenance and protection of tissue ho-meostasis. It is well established that tissue diversity is reflected by the heterogeneity of resident tissue macrophage origin and phenotype. However, much less is known about tissue-specific phagocytic and proteolytic macrophage functions. Here, using a quantitative proteomics approach, we identify cathepsins as key determinants of phagosome maturation in primary peritoneum-, lung-, and brain-resident macrophages. The data further uncover cathepsin K (CtsK) as a molecular marker for lung phagosomes required for intracellular protein and collagen degradation. Pharmacological blockade of CtsK activity diminished phag-osomal proteolysis and collagenolysis in lung-resident mac-rophages. Furthermore, profibrotic TGF-beta negatively regulated CtsK-mediated phagosomal collagen degradation indepen-dently from classical endocytic-proteolytic pathways. In humans, phagosomal CtsK activity was reduced in COPD lung macrophages and non-COPD lung macrophages exposed to cig-arette smoke extract. Taken together, this study provides a comprehensive map of how peritoneal, lung, and brain tissue environment shapes phagosomal composition, revealing CtsK as a key molecular determinant of lung phagosomes contributing to phagocytic collagen clearance in lungs.
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| 25. |
- Fornes, R., et al.
(författare)
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Mice exposed to maternal androgen excess and diet-induced obesity have altered phosphorylation of catechol-O-methyltransferase in the placenta and fetal liver
- 2019
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Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 43:11, s. 2176-2188
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Tidskriftsartikel (refereegranskat)abstract
- Background/objectives Maternal obesity together with androgen excess in mice negatively affects placental function and maternal and fetal liver function as demonstrated by increased triglyceride content with dysfunctional expression of enzymes and transcription factors involved in de novo lipogenesis and fat storage. To identify changes in molecular pathways that might promote diseases in adulthood, we performed a global proteomic analysis using a liquid-chromatography/massspectrometry system to investigate total and phosphorylated proteins in the placenta and fetal liver in a mouse model that combines maternal obesity with maternal androgen excess. Methods After ten weeks on a control diet (CD) or high fat/high sugar-diet, dams were mated with males fed the CD. Between gestational day (GD) 16.5 and GD 18.5, mice were injected with vehicle or dihydrotestosterone (DHT) and sacrificed at GD 18.5 prior to dissection of the placentas and fetal livers. Four pools of female placentas and fetal livers were subjected to a global proteomic analysis. Total and phosphorylated proteins were filtered by ANOVA q < 0.05, and this was followed by two-way ANOVA to determine the effect of maternal obesity and/or androgen exposure. Results In placenta, phosphorylated ATP-citrate synthase was decreased due to maternal obesity, and phosphorylated catechol-O-methyltransferase (COMT) was differentially expressed due to the interaction between maternal diet and DHT exposure. In fetal liver, five total proteins and 48 proteins phosphorylated in one or more sites, were differentially expressed due to maternal obesity or androgen excess. In fetal liver, phosphorylated COMT expression was higher in fetus exposed to maternal obesity. Conclusion These results suggest a common regulatory mechanism of catecholamine metabolism in the placenta and the fetal liver as demonstrated by higher phosphorylated COMT expression in the placenta and fetal liver from animals exposed to dietinduced maternal obesity and lower expression of phosphorylated COMT in animals exposed to maternal androgen excess.
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