Case Report: Severe Hypercalcemia Following Vitamin D Intoxication in an Infant, the Underestimated Danger of Dietary Supplements

Vitamin D supplementation is routinely introduced in infants, according to medical guidelines. However, vitamin D overdose can result in life-threatening hypercalcemia. We report the case of a 3-month-old infant who suffered from severe hypercalcemia. Upon detailed questioning of the parents, a vitamin D administration error has been identified. Indeed, the parents had followed the advice of their midwife. They substituted the prescribed medicinal vitamin D by a dietary supplement, different in concentration and dosing, without performing the dose conversion needed. In fact, many different medications and dietary supplements with vitamin D exist, offering various concentrations and units of measurement. This case highlights the pivotal role of therapeutic education. Broadly, there is a need for harmonization of the regulation and labeling of dietary supplements and medications containing vitamin D.

A novel class of small tRNA-like noncoding transcripts arising from the human NEAT1-MALAT1 region critically influences innate immunity and angiogenesis

Background

The evolutionary conserved NEAT1-MALAT1 gene cluster encounters high interest in cardiovascular medicine and oncology. The cluster generates large primary transcripts which remain nuclear, whereas novel tRNA-like transcripts (mascRNA, menRNA) enzymatically generated from these precursors translocate to the cytosol. We previously found that NEAT1 and MALAT1 deficient mice display accelerated atherosclerosis and vascular inflammation due to immune dysfunctions.

Methods

While the previously investigated mice were deficient in the entire NEAT1 or MALAT1 locus, here we aimed to selectively disrupt only tRNA-like transcripts “menRNA” arising from NEAT1, or “mascRNA” arising from MALAT1. To none of these a biological function has been assigned so far. Both lncRNAs give rise to transcripts of vastly different size (NEAT1: 23kb MENb, 3.7kb MENe, 59nt “menRNA”; MALAT1: 8.3 kb primary, 59nt “mascRNA”), and traditional knockout methods are unable to selectively inactivate one of the small transcripts only. Through CRISPR/Cas9 editing we therefore developed human monocyte-macrophage cell lines with short deletions in the respective tRNA-encoding sequences to disrupt normal menRNA or mascRNA formation, respectively. These editing procedures do not affect transcription of the respective lncRNA parent transcripts, and also not disturb regular formation of the triple-helix structures at their 3'-ends which support stabilization of the respective lncRNAs (Fig. 1).

Results

We found the tRNA-like transcripts menRNA and mascRNA critically influence innate immunity and angiogenesis. In addition to common anomalies resulting from their selective CRISPR-Cas9 mediated deletion (Fig. 1), there are specific disturbances associated with either Δmasc or Δmen cells (Fig. 2).

Both ΔmascRNA and ΔmenRNA human monocytes show profoundly altered ribosomal RNA/protein and tRNA-modifying enzyme expression, display anomalous growth/ angiogenetic factor expression, fundamentally change angiogenetic patterns in co-cultures with human endothelial cells, and have gravely disturbed innate immune responses (LPS, DNA and RNA viruses) (Fig. 1).

CRISPR-engineered ΔmenRNA cells share remakable similarities with human post-MI PBMCs, suggesting the NEAT1-menRNA system may significantly contribute to post-MI residual inflammatory risk despite optimal standard therapy (Fig. 2).

Conclusions

Beyond prior work in knockout mice documenting immune function of the NEAT1-MALAT1 cluster, the current study identifies menRNA and mascRNA as important novel components of human innate immunity with relevance for angiogenetic processes. These data provide a second mechanistic link for the apparent relevance of the NEAT1-MALAT1 gene cluster in cardiovascular and malignant diseases. As prototypes of a novel class of small noncoding RNAs (distinct from miRNAs and siRNAs) they may constitute cytosolic therapeutic targets.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): DZHK Shared Expertise Project/B19-006_SE/FKZ 81X2100257/Transcriptome analysis of circulating immune cells to improve the assessment of prognosis and the response to novel anti-inflammatory treatments after myocardial infarction Figure 1. Common anomaliesFigure 2. Specific anomalies

Effectiveness and cost effectiveness of a stress management training for leaders of small and medium sized enterprises - study protocol for a randomized controlled-trial

BACKGROUND

Leaders in small and medium-sized enterprises (SMEs) are exposed to increased stress as a result of a range of challenges. Moreover, they rarely have the opportunity to participate in stress management trainings. Therefore, KMU-GO (ger: Kleine und mittlere Unternehmen - Gesundheitsoffensive; en: small and medium-sized enterprises - health campaign) aims at conducting and evaluating such a stress management training. The focus of evaluation does not only lie on the effects on leaders participating but also on their employees.

METHODS

The study is planned as a 2 × 3 mixed design with two groups (intervention and waiting control group) as a between factor and point in time (at baseline, 6 and 12 months later) as a within factor. We aim at collecting data from N = 200 leaders. Based on the results of a preceding assessment, an already successfully implemented stress management training was adapted to SME needs and now serves as the framework of this intervention. The stress management training comprises one and a half days and is followed by two booster sessions (each 180 min) about 3 and 6 months after the training. The main focus of this intervention lies on specifying leaders stress reactivity while at the same time investigating its effects on employees' mental health. Further dependent variables are leaders´ depression and anxiety scores, effort-reward imbalance, sick days and psychophysiological measures of heart rate variability, hair cortisol, and salivary alpha-amylase. Cost-effectiveness analyses will be conducted from a societal and employers' point of view.

DISCUSSION

Stress management is a highly relevant issue for leaders in SMEs. By providing an adequate occupational stress management training, we expect to improve leaders´ and also employees` mental health, thereby preventing economic losses for SMEs and the national economy. However, collecting data from employees about the success of a stress management training of their leader is a highly sensitive topic. It requires a carefully planned proceeding ensuring for example a high degree of transparency, anonymity, and providing team incentives.

TRIAL REGISTRATION

The KMU-GO trial is registered at the German Clinical Trial Register (DRKS): DRKS00023457 (05.11.2020).

Experimental and population-genetic evidence for inflammation control functions of long noncoding RNAs and a novel tRNA-like transcript arising from the human NEAT1-MALAT1 genomic region

Background

Uncontrolled inflammation is a key driver of atherosclerosis, myocardial infarction (MI), and multiple other diseases. Beyond proteins and microRNAs, long noncoding RNAs (lncRNAs) are implicated in inflammation control. We previously reported suppression of lncRNA NEAT1 in circulating immune cells of post-MI patients. In mice lacking lncRNAs NEAT1 or MALAT1 we observed major immune disturbances affecting monocyte-macrophage and T cell differentiation and rendering the immune system unstable and highly vulnerable to immune stress. Here, we report functions of a novel tRNA-type transcript arising from the NEAT1-MALAT1 gene cluster, and on genetic heterogeneity of this region in the human population.

Methods and results

While previously investigated mice were deficient in the entire NEAT1 or MALAT1 locus, we here aimed to selectively disrupted only the novel 59-nt tRNA-like transcript “menRNA” with hitherto unknown functions. Through CRISPR/Cas9 editing we developed 4 human THP-1 monocyte-macrophage cell line clones with deletions of different extension all of which prevented, however, normal transcript folding and formation of “menRNA”. Transcriptome mapping of all clones by RNA-sequencing identified dysregulation of innate immunity-related genes (IFI16, IFITM3, IRAK3, IRF2BP2, IRF3), chemokine and interleukin receptors (CCR10, IL11RA, IL12RB2, IL23A), cell surface receptors (CD37, CD40LG, CD72, FOCAD, ITGA6, MAEA, THY1), macrophage function-associated genes (ELANE, GRN, MIF, MMP25, MST1P2, PRTN3), tRNA-processing transcripts (GARS, QRSL1P3, QTRT1P1, THG1L, VARS), and small nucleolar RNAs (SNORA26.62.64, SNORD65.112). These data and functional assays indicate functions of NEAT1-derived “menRNA” distinct from those previously described for MALAT1-derived mascRNA.

As multiple data suggest inflammation control functions of the NEAT1-MALAT1 region, we investigated the extent of genetic variability of this region in humans. In cohorts from the SHIP study coordinated by the Institute for Community Medicine Greifswald, screening of this region for sequence variants and possible phenotype associations was conducted the results of which are given in Figure 1. Consistent with prior findings, a MALAT1 SNP with very low minor allele frequency (MAF=0.01) was associated (p=0.0062) with systemic low level inflammation (CRP >3.0 mg/L). Unexpected was the association (p<0.01) of eight SNPs (low MAF=0.09 for all) with BMI >35 kg/m2 and LDL >164 mg/dl.

Conclusions

First, selective disruption of menRNA formation in human monocyte-macrophages provides evidence that this novel type of noncoding RNA has immunoregulatory functions. Second, the phenotype associations of SNPs within the NEAT1-MALAT1 gene cluster warrant further in-depth investigation of the molecular basis of these associations, and of their allele frequencies in cardiovascular disease patient cohorts.

The first three and the last authors contributed equally to this work.

Figure 1

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): “Transcriptome analysis of circulating immune cells to improve the assessment of prognosis and the response to novel anti-inflammatory treatments after myocardial infarction”; DZHK Shared Expertise project B19-006_SE FKZ 81X2100257

Impact of the gut microbiome on the atorvastatin-dependent modulation of the serum lipidome

Background and aims

The modulation of serum lipids, in particular of the low-density lipoprotein cholesterol (LDL-C), by statins varies between individuals. The mechanisms regulating this interindividual variation are only poorly understood. Here, we investigated the relation between the gut microbiome and the regulatory properties of atorvastatin on the serum lipidome using mice with depleted gut microbiome.

Methods

Over a period of 6 weeks, mice (C57BL/6) with either an intact (conventional mice, CONV, n=24) or antibiotic-based depleted gut microbiome (antibiotic treated mice, ABS, n=16) were put on standard chow diet (SCD) or high fat diet (HFD), respectively. During the last 4 weeks of treatment atorvastatin (Ator, 10mg/kg body weight/day) or control vehicle was administered via daily oral gavage. Blood lipids (total cholesterol, VLDL, LDL-C, HDL-C) and serum sphingolipids were compared among the groups. The expressions of hepatic and intestinal genes involved in cholesterol metabolism were analyzed by qRT-PCR. Alterations in the gut microbiota profile of mice with intact gut microbiome were examined using 16S RNA qRT-PCR.

Results

In CONV mice, HFD led to significantly increased blood LDL-C levels as compared with SCD (HFD: 36.8±1.4 mg/dl vs. SCD: 22.0±1.8 mg/dl; P<0.01). In CONV mice atorvastatin treatment significantly reduced blood LDL-C levels after HFD, whereas in ABS mice the LDL-C lowering effect of atorvastatin was markedly attenuated (CONV+HFD+Ator: 31.0±1.8 mg/dl vs. ABS+HFD+Ator: 46.4±3 mg/dl; P<0.01). A significant reduction in the abundance of several plasma lipids, in particular sphingolipids and glycerophospholipids upon atorvastatin treatment was observed in CONV mice, but not in ABS mice. The expressions of distinct hepatic and intestinal cholesterol-regulating genes (ldlr, srebp2, pcsk9 and npc1l1) upon atorvastatin treatment were significantly altered in gut microbiota depleted mice. In response to HFD a decrease in the relative abundance of the bacterial phyla Bacteroides and an increase in the relative abundance of Firmicutes was observed. The altered ratio between Bacteroides and Firmicutes in HFD fed mice was partly reversed upon atorvastatin treatment.

Conclusions

Our findings indicate a crucial role of the gut microbiome for the regulatory properties of atorvastatin on the serum lipidome and, in turn, support a critical impact of atorvastatin on the gut microbial composition. The results provide novel insights into potential microbiota related mechanisms underlying interindividual variation in modulation of the serum lipidome by statins, given interindividual differences in microbiome composition and function.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): German Heart Research Foundation

P5393Deficiency of the long noncoding RNA NEAT1 disturbs T cell and monocyte-macrophage lineage differentiation and functions and results in systemic inflammation with high circulating interferon levels

Background

Inflammation is a key driver of atherosclerosis and myocardial infarction (MI), and beyond proteins and microRNAs, long noncoding RNAs (lncRNAs) are implicated in inflammation control. To obtain further information on the role of lncRNAs in the context of atherosclerosis, we analyzed transcriptome maps of circulating immune cells (PBMCs) of post-MI patients in whom the lncRNA NEAT1 was suppressed. Here, we report immune disturbances in murine NEAT1 knockout models with wildtype or ApoE−/− genetic background.

Methods and results

RNA-sequencing (RNA-seq) of PBMCs from post-MI patients revealed profound transcriptome disturbances compared to healthy controls. Among these, NEAT1 suppression was notable since it affected the most highly expressed lncRNA as part of a molecular circuit also encompassing chemokines and interleukins.

We used NEAT1−/− mice to evaluate whether NEAT1 depletion per se may cause immune dysfunction. NEAT1−/− splenocytes displayed enhanced baseline ROS production, and RNA-seq identified anomalous expression and regulation of chemokines/ receptors, innate immunity genes, TNF and caspases. FACS revealed displayed anomalous Treg and TH cell differentiation in NEAT1−/− spleens vs. wildtype (WT).

Beyond grossly altered transcriptome, NEAT1−/− bone marrow derived macrophages (BMDMs) responded to LPS with increased (p<0.001) ROS production, enhanced baseline phagocytic activity (p<0.001), and attenuated proliferation (p=0.001). FACS revealed deregulated monocyte-macrophage differentiation in NEAT1−/− bone marrow and blood.

Further, NEAT1−/− mice displayed aortic wall CD68+ cell infiltration and there was evidence of myocardial inflammation which could lead to severe and potentially life-threatening structural damage in some of these animals. This observation suggests that even stochastic activation of the highly unstable NEAT1−/− immune system may trigger uncontrolled pathogenic cascades, explaining the survival disadvantage of NEAT1−/− mice.

In addition to these studies on homozygous NEAT1−/− deficiency in WT background, we obtained data on mice with partial i.e. heterozygous NEAT1−/+ deficiency on ApoE−/− background. Analysis of this new NEAT1−/+ ApoE−/− strain indicates that even partial NEAT1 deficiency leads to systemic inflammation with high IFN-gamma levels, when the animals are exposed to immune stress e.g. high LDL cholesterol.

Conclusions

Regarding the monocyte-enriched NEAT1 suppressed in post-MI PBMCs, the data from NEAT1−/− and NEAT1−/+ ApoE−/− mice document NEAT1 as a key immune system coordinator whose deficiency affects monocyte-macrophage and T cell differentiation and functions and renders the immune system unstable and highly vulnerable to immune stress. Since in patients NEAT1 is part of a molecular circuit persistently deregulated post-MI, too, it appears reasonable to further search for new therapeutic targets within this circuit, taking advantage of the described genetic animal models.

P3688Familial recurrent autoimmune myocarditis associated with a truncating nonsense mutation of the desmoplakin gene

Background

Arrhythmogenic cardiomyopathy (AC) is an important cause of ventricular arrhythmias in children and young adults. AC is associated with mutation of desmosomal proteins, however, cardiac disease penetrance is incomplete and the clinical course varies widely without recognizable exogenous or epi/genetic co-factors. Importantly, DSP mutation carriers may also display entirely non-cardiac e.g. dermatological phenotypes.

Methods and results

In two brothers with recurrent fulminant myocarditis, mutation screening of 218 cardiomyopathy-related genes identified a truncating mutation Arg1458* of desmoplakin (DSP). DSP immunhistology unexpectedly revealed complete loss (“knockout”) of DSP protein in endomyocardial biopsies (EMBs), but none of the histological anomalies of AC. Criteria for histological diagnosis of myocarditis were not either fulfilled, and cardiac MRI revealed no features associated with AC. Screening for infections was negative, there was no substance abuse, medication or vaccination. Possible disease triggers were competitive sport events. Myosin and troponin I autoantibodies were detected at titers up to 1:320.

We used allele-specific RT-PCR to distinguish if the patients' allele classified as “normal” was actually defective due to promotor mutation or epigenetic silencing. RT-PCRs were done on EMBs and peripheral blood mononuclear cells (PBMCs). In a cohort of dilated cardiomyopathy (DCM) patients we were able to detect DSP transcripts in both, PBMC and left-ventricular heart tissue. RNA sequencing of human PBMC subpopulations suggested that DSP transcription may be restricted to certain immune cell subtypes. RT-PCRs revealed that both Arg1458* carriers have a functional second DSP allele, indicating that their “DSP knockout” occurs at the protein level and may be due to protein instability and degradation within desmosomes.

We screened additional existing cohorts for such variants and identified stopgain variant Gln307Ter in a 37-yrs-old woman with ARVC. This patient's sister died from heart failure at the age of 39. In a 59-yrs-old female LVNC patient, stopgain variant Y1391X was identified. Here, family history was unclear, her brother probably died from coronary artery disease. In a 71-yrs-old female DCM patient with no family history, stopgain variant Tyr1512Ter was identified.

Conclusions

The described patients with DSP truncations strongly suggest the existence of additional genetic or exogenous modifiers driving pathogenesis either way. DSP defects may cause recurrent myocarditis, and mutation screening is advisable to enable early detection of high-risk patients with similar phenotypes. Our finding of complete myocardial DSP protein loss emphasizes that DNA sequencing may miss critical molecular disturbances. It is indispensable to also analyze transcriptome and protein level in the tissue actually affected in a patient in order to recognize his/her individual pathogenesis.

54Role of the gut microbiome for the cholesterol lowering effect of atorvastatin

Background and aims

Statins show interindividual differences in the extent of low-density lipoprotein cholesterol (LDL-C) reduction. The mechanisms of this interindividual variation are not fully understood. Here, we examined the potential role of the gut microbiome for the LDL-C lowering property of atorvastatin.

Methods

Mice (C57BL/6) with either intact (conventional mice, CONV, n=24) or with antiobiotic depleted gut microbiome (gnotobiotic, n=16), were put on standard chow diet (SCD) (n=11) or high fat diet (HFD) (n=29) for 6 weeks. During the last 4 weeks atorvastatin (Ator, 10mg/kg body weight/day) or control vehicle was orally applied via gavage. Blood levels of LDL-C and glucose and body weight after 6 weeks of treatment were compared between the groups. Expression of genes involved in hepatic and intestinal cholesterol-metabolism were examined. Faeces of CONV mice were analyzed for alteration of the gut microbiota profile upon atorvastatin treatment using 16S rRNA qPCR.

Results

HFD fed mice with intact gut microbiome showed significantly increased blood LDL-C levels as compared to SCD (HFD: 36.8±1.4 mg/dl vs. SCD: 22.0±1.8 mg/dl; P<0.01). Bodyweight gain or blood glucose levels after HFD were not significantly different between CONV and gnotobiotic mice. While in CONV mice atorvastatin significantly reduced LDL-C levels after HFD, in gnotobiotic mice the LDL-C lowering effect of atorvastatin was attenuated (CONV+HFD+Ator: 31.0±1.8 mg/dl vs. gnotobiotic mice+HFD+Ator: 46.4±3 mg/dl; P<0.01). The expression of genes involved in hepatic cholesterol synthesis was not significantly altered in gnotobiotic mice as compared to CONV mice. In CONV mice HFD decreased the relative abundance of the bacterial phyla Bacteroidetes and increased the abundance of Firmicutes as compared to SCD. The ratio between Firmicutes to Bacteroidetes was shifted towards control conditions upon atorvastatin treatment.

Conclusions

The results of this study suggest a regulatory impact of atorvastatin on the gut-microbial profile and, in turn, a crucial role of the gut-microbiome for the LDL-C lowering effect of atorvastatin independent of its regulation of hepatic cholesterol synthesis. Our findings provide novel insight into potential microbiota-related mechanisms causing interindividual variation in LDL-C lowering effects of statins.

Acknowledgement/Funding

German Heart Research Foundation

Understanding the viral load during the synthesis and after rebinding of virus imprinted particles via real-time quantitative PCR

In the present study, virus imprinted particles have been synthesized for recognizing and specifically binding viruses. These materials may be used for biomimetic sensing schemes and for selective removal of virus particles. Virus imprinting procedures require careful optimization of the synthesis route for obtaining selective and efficiently binding imprinted materials. A remaining limitation has been a facile method for the quantification of the viral load during the imprinting process. Herein, human adenovirus (AdV) was selected as a model virus facilitating the development and application of a rapid virus quantification method based on a molecular biological approach. A real-time quantitative polymerase chain reaction, a.k.a., the qPCR method was developed for monitoring the AdV viral load during the synthesis of AdV imprinted particles, and subsequent rebinding studies. The developed analytical strategy allows the direct, rapid, and sensitive quantification of human adenovirus type 5 concentrations during synthesis and application of AdV imprinted polymers (AdV-MIPs) with a broad dynamic range suitable for both application scenarios. In addition, it was demonstrated by gel electrophoresis analysis that viruses indeed bind to the beads even after several washing steps.