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Contains fulltext : 293805.pdf (Publisher’s version ) (Open Access) OBJECTIVE: Thyroid hormone (TH) transport represents a critical first step in governing intracellular TH regulation. It is still unknown whether the full repertoire of TH transporters has been identified. Members of the solute carrier (SLC) 22 family have substrates in common with the known TH transporters of the organic anion-transporting peptide family. Therefore, we screened the SLC22 family for TH transporters. METHODS: Uptake of 1 nM of iodothyronines or sulfated iodothyronines in COS1 cells expressing SLC22 proteins was performed. RESULTS: We first tested 25 mouse (m) SLC22 proteins for TH uptake and found that the majority of the organic anion transporter (OAT) clade were capable of 3,3',5-triiodothyronine and/or thyroxine (T4) transport. Based on phylogenetic tree analysis of the mouse and human (h) SLC22 family, we selected eight hSLC22s that grouped with the newly identified mouse TH transporters. Of these, four tested positive for uptake of one or more substrates, particularly hSLC22A11 showed robust (3-fold over control) uptake of T4. Uptake of sulfated iodothyronines was strongly (up to 17-fold) induced by some SLC22s, most notably SLC22A8, hSLC22A9, mSLC22A27 and mSLC22A29. Finally, the zebrafish orthologues of SLC22A6/8 drOatx and drSlc22a6l also transported almost all (sulfated) iodothyronines tested. The OAT inhibitors lesinurad and probenecid inhibited most SLC22 proteins. CONCLUSIONS: Our results demonstrated that members of the OAT clade of the SLC22 family constitute a novel, evolutionary conserved group of transporters for (sulfated) iodothyronines. Future studies should reveal the relevance of these transporters in TH homeostasis and physiology.

Background and aims: Homozygous familial hypercholesterolemia (HoFH) is characterized by severely elevated low-density lipoprotein cholesterol (LDL-C) levels leading to extremely premature atherosclerotic cardiovascular disease. Therefore, healthcare professionals consider HoFH to have major impact on patients’ life. Remarkably, little is known on how patients deal with their condition. The aim of this study is to investigate how Dutch patients experience and cope with HoFH in daily life. Methods: Adult patients with genetically confirmed HoFH, treated at the 3 specialized HoFH-centers in the Netherlands, were interviewed in-depth. Interview transcripts were analyzed according to grounded theory. Health-related quality of life (QoL) and coping were measured with the EuroQol (EQ)-5D-5L questionnaire and the Threatening Medical Situations Inventory (TMSI), respectively. Results: 20 Dutch HoFH patients were interviewed: 50% women, median age 38 years, 60% with cardiovascular disease, 10% on apheresis. Coding of the transcripts resulted in a conceptual model, with disease perception as the central theme. Individual TMSI-results corresponded to the interviews, with most patients showing both monitoring (information-seeking behavior) and blunting (distractive strategies) coping styles. The median EQ-5D-5L health utility score (0.839) was only 5% below the Dutch population (0.887). Transient anxiety was reported when confronted with the consequences of HoFH in daily life. Patients reported high confidence in treatment by a dedicated HoFH center, which helped them cope with their disease. Conclusions: Dutch HoFH patients use a variety of effective coping mechanisms in such a way that their subjective QoL is only slightly affected. Healthcare professionals can use this knowledge to tailor their care to the specific needs of these patients.

Contains fulltext : 251929.pdf (Publisher’s version ) (Open Access) Many people, particularly elderly, experience dizziness upon standing. It is important to always measure the blood pressure and heart rate in the supine and standing position in these patients. In case of orthostatic hypotension with an insufficient increase in heart rate, one has to consider autonomic dysfunction. Alpha-synucleopathies are frequent causes of autonomic dysfunction, including Parkinson's disease, Pure Autonomic Failure and Multiple System Atrophy. The quality of life can significantly be improved in patients with autonomic dysfunction due to life-style measures (increased salt and water intake, compressive stockings, head-up sleeping) and medication to increase blood pressure (fludrocortisone, midodrine). There is often a considerable delay in the diagnosis of autonomic dysfunction, which prevents adequate treatment. The main message of this paper is that we should all search for orthostatic hypotension in patients with dizziness and, in case of insufficient heart rate increase, refer these patients for autonomic function testing.

Contains fulltext : 251930.pdf (Publisher’s version ) (Closed access) Although transient loss of consciousness (TLOC) is a common problem, hospital care for patients with TLOC is characterised by high rates of no diagnosis and misdiagnosis, accompanied by unnecessary hospital admissions and tests. We attribute these problems to increasing specialisation as well as to a blind spot for vasovagal syncope, a condition not claimed by any specialty. We suggest that all doctors seeing patients with TLOC, both in primary and secondary care, should be familiar with the presentations of the relatively harmless vasovagal syncope and the alarm symptoms of potentially life-threatening cardiac syncope. In this article we present some practical pointers to recognise these conditions and answer some frequently-asked questions regarding the diagnosis and treatment of TLOC.

Rationale: Altered gut microbial composition has been linked to cardiovascular diseases (CVDs), but its functional links to host metabolism and immunity in relation to CVD development remain unclear. Objectives: To systematically assess functional links between the microbiome and the plasma metabolome, cardiometabolic phenotypes, and CVD risk and to identify diet-microbe-metabolism-immune interactions in well-documented cohorts. Methods and Results: We assessed metagenomics-based microbial associations between 231 plasma metabolites and microbial species and pathways in the population-based LLD (Lifelines DEEP) cohort (n=978) and a clinical obesity cohort (n=297). After correcting for age, sex, and body mass index, the gut microbiome could explain ≤11.1% and 16.4% of the variation in plasma metabolites in the population-based and obesity cohorts, respectively. Obese-specific microbial associations were found for lipid compositions in the VLDL, IDL, and LDL lipoprotein subclasses. Bacterial L-methionine biosynthesis and a Ruminococcus species were associated to cardiovascular phenotypes in obese individuals, namely atherosclerosis and liver fat content, respectively. Integration of microbiome-diet-inflammation analysis in relation to metabolic risk score of CVD in the population cohort revealed 48 microbial pathways associated to CVD risk that were largely independent of diet and inflammation. Our data also showed that plasma levels rather than fecal levels of short-chain fatty acids were relevant to inflammation and CVD risk. Conclusions: This study presents the largest metagenome-based association study on plasma metabolism and microbiome relevance to diet, inflammation, CVD risk, and cardiometabolic phenotypes in both population-based and clinical obesity cohorts. Our findings identified novel bacterial species and pathways that associated to specific lipoprotein subclasses and revealed functional links between the gut microbiome and host health that provide a basis for developing microbiome-targeted therapy for disease prevention and treatment.

Contains fulltext : 198215.pdf (Publisher’s version ) (Open Access)

Contains fulltext : 228881.pdf (Publisher’s version ) (Open Access) Radboud University, 28 januari 2021 Promotores : Graaf, J. de, Riksen, N.P., Joosten, L.A.B. Co-promotor : Rutten, J.H.W. 242 p.