Functional and Morphological Differences of Muscle Mitochondria in Chronic Fatigue Syndrome and Post-COVID Syndrome.

Patients suffering from chronic fatigue syndrome (CFS) or post-COVID syndrome (PCS) exhibit a reduced physiological performance capability. Impaired mitochondrial function and morphology may play a pivotal role. Thus, we aimed to measure the muscle mitochondrial oxidative phosphorylation (OXPHOS) capacity and assess mitochondrial morphology in CFS and PCS patients in comparison to healthy controls (HCs). Mitochondrial OXPHOS capacity was measured in permeabilized muscle fibers using high-resolution respirometry. Mitochondrial morphology (subsarcolemmal/intermyofibrillar mitochondrial form/cristae/diameter/circumference/area) and content (number and proportion/cell) were assessed via electron microscopy. Analyses included differences in OXPHOS between HC, CFS, and PCS, whereas comparisons in morphology/content were made for CFS vs. PCS. OXPHOS capacity of complex I, which was reduced in PCS compared to HC. While the subsarcolemmal area, volume/cell, diameter, and perimeter were higher in PCS vs. CFS, no difference was observed for these variables in intermyofibrillar mitochondria. Both the intermyofibrillar and subsarcolemmal cristae integrity was higher in PCS compared to CFS. Both CFS and PCS exhibit increased fatigue and impaired mitochondrial function, but the progressed pathological morphological changes in CFS suggest structural changes due to prolonged inactivity or unknown molecular causes. Instead, the significantly lower complex I activity in PCS suggests probably direct virus-induced alterations.

A precisely positioned MED12 activation helix stimulates CDK8 kinase activity.

The Mediator kinase module regulates eukaryotic transcription by phosphorylating transcription-related targets and by modulating the association of Mediator and RNA polymerase II. The activity of its catalytic core, cyclin-dependent kinase 8 (CDK8), is controlled by Cyclin C and regulatory subunit MED12, with its deregulation contributing to numerous malignancies. Here, we combine in vitro biochemistry, cross-linking coupled to mass spectrometry, and in vivo studies to describe the binding location of the N-terminal segment of MED12 on the CDK8/Cyclin C complex and to gain mechanistic insights into the activation of CDK8 by MED12. Our data demonstrate that the N-terminal portion of MED12 wraps around CDK8, whereby it positions an "activation helix" close to the T-loop of CDK8 for its activation. Intriguingly, mutations in the activation helix that are frequently found in cancers do not diminish the affinity of MED12 for CDK8, yet likely alter the exact positioning of the activation helix. Furthermore, we find the transcriptome-wide gene-expression changes in human cells that result from a mutation in the MED12 activation helix to correlate with deregulated genes in breast and colon cancer. Finally, functional assays in the presence of kinase inhibitors reveal that binding of MED12 remodels the active site of CDK8 and thereby precludes the inhibition of ternary CDK8 complexes by type II kinase inhibitors. Taken together, our results not only allow us to propose a revised model of how CDK8 activity is regulated by MED12, but also offer a path forward in developing small molecules that target CDK8 in its MED12-bound form.

Current state and future perspective of drug repurposing in malignant glioma.

Malignant gliomas are still extremely difficult to treat because complete surgical resection is biologically not feasible due to the invasive nature of these diseases and the proximity of tumors to functionally sensitive areas. Moreover, adjuvant therapies are facing a strong therapeutic resistance since the central nervous system is a highly protected environment and the tumor cells display a vast intra-tumoral genetic and epigenetic variation. As a consequence, new therapeutics are urgently needed but the process of developing novel compounds that finally reach clinical application is highly time-consuming and expensive. Drug repurposing is an approach to facilitate and accelerate the discovery of new cancer treatments. In malignant glioma, like in other cancers, pre-existing physiological pathways that regulate cell growth, cell death or cell migration are dysregulated causing malignant transformation. A wide variety of drugs are clinically used to treat non-cancerous diseases interfering with these malignancy-associated pathways. Repurposed drugs have key advantages: They already have approval for clinical use by national regulatory authorities. Moreover, they are for the most part inexpensive and their side effect and safety profiles are well characterized. In this work, we provide an overview on current repurposing strategies for the treatment of malignant glioma.

Mediator kinase inhibition further activates super-enhancer-associated genes in AML.

Super-enhancers (SEs), which are composed of large clusters of enhancers densely loaded with the Mediator complex, transcription factors and chromatin regulators, drive high expression of genes implicated in cell identity and disease, such as lineage-controlling transcription factors and oncogenes. BRD4 and CDK7 are positive regulators of SE-mediated transcription. By contrast, negative regulators of SE-associated genes have not been well described. Here we show that the Mediator-associated kinases cyclin-dependent kinase 8 (CDK8) and CDK19 restrain increased activation of key SE-associated genes in acute myeloid leukaemia (AML) cells. We report that the natural product cortistatin A (CA) selectively inhibits Mediator kinases, has anti-leukaemic activity in vitro and in vivo, and disproportionately induces upregulation of SE-associated genes in CA-sensitive AML cell lines but not in CA-insensitive cell lines. In AML cells, CA upregulated SE-associated genes with tumour suppressor and lineage-controlling functions, including the transcription factors CEBPA, IRF8, IRF1 and ETV6 (refs 6-8). The BRD4 inhibitor I-BET151 downregulated these SE-associated genes, yet also has anti-leukaemic activity. Individually increasing or decreasing the expression of these transcription factors suppressed AML cell growth, providing evidence that leukaemia cells are sensitive to the dosage of SE-associated genes. Our results demonstrate that Mediator kinases can negatively regulate SE-associated gene expression in specific cell types, and can be pharmacologically targeted as a therapeutic approach to AML.

Anti-glioma Activity of Dapsone and Its Enhancement by Synthetic Chemical Modification.

The sulfone dapsone is an old antibiotic used for the treatment of mycobacterial and protozoal infections. We postulated before that dapsone might possess biological activity exceeding its anti-infectious properties and that it could potentially be repurposed for the treatment of glioma. To test this hypothesis, we treated established and primary cultured glioma cells with dapsone or several dapsone analogues which we previously synthesized (D2-D5) and determined effects on proliferation, anchorage-independent growth and migration. While dapsone and its synthetic analogues D2-D5 displayed only modest anti-proliferative activity, important neoplastic features such as anchorage-independent growth, clonogenic survival and directed migration were significantly inhibited by dapsone treatment. Moreover, dapsone analogues D3, D4 and D5 yielded even enhanced anti-glioma activity against different pro-neoplastic features. Overall these data suggest that dapsone provides activity against glioma which can be further enhanced by molecular modifications. These compounds could potentially serve as a therapeutic adjunct to the treatment of gliomas in a repurposing approach.

Structure-kinetic relationship study of CDK8/CycC specific compounds.

In contrast with the very well explored concept of structure-activity relationship, similar studies are missing for the dependency between binding kinetics and compound structure of a protein ligand complex, the structure-kinetic relationship. Here, we present a structure-kinetic relationship study of the cyclin-dependent kinase 8 (CDK8)/cyclin C (CycC) complex. The scaffold moiety of the compounds is anchored in the kinase deep pocket and extended with diverse functional groups toward the hinge region and the front pocket. These variations can cause the compounds to change from fast to slow binding kinetics, resulting in an improved residence time. The flip of the DFG motif ("DMG" in CDK8) to the inactive DFG-out conformation appears to have relatively little influence on the velocity of binding. Hydrogen bonding with the kinase hinge region contributes to the residence time but has less impact than hydrophobic complementarities within the kinase front pocket.

Cryo-EM Structures of CRAF2/14-3-32 and CRAF2/14-3-32/MEK12 Complexes.

RAF protein kinases are essential effectors in the MAPK pathway and are important cancer drug targets. Structural understanding of RAF activation is so far based on cryo-electron microscopy (cryo-EM) and X-ray structures of BRAF in different conformational states as inactive or active complexes with KRAS, 14-3-3 and MEK1. In this study, we have solved the first cryo-EM structures of CRAF2/14-3-32 at 3.4 Å resolution and CRAF2/14-3-32/MEK12 at 4.2 Å resolution using CRAF kinase domain expressed as constitutively active Y340D/Y341D mutant in insect cells. The overall architecture of our CRAF2/14-3-32 and CRAF2/14-3-32/MEK12 cryo-EM structures is highly similar to corresponding BRAF structures in complex with 14-3-3 or 14-3-3/MEK1 and represent the activated dimeric RAF conformation. Our CRAF cryo-EM structures provide additional insights into structural understanding of the activated CRAF2/14-3-32/MEK12 complex.

Dataset on electrical single-family house and heat pump load profiles in Germany.

This paper describes a dataset of residential electricity household and heat pump load profiles, measured in 38 single-family houses in Northern Germany. We provide data per household of apparent, active and reactive power (W), voltage (V), current (A) and the power factor (no unit) in 10 seconds to 60 minutes temporal resolution from May 2018 to the end of 2020. We validated the dataset both in itself, comparing different measurements that should produce the same results, and externally to standard load profiles and found no major inconsistencies. We identified an average consumption per single-family house with 2.38 inhabitants of 2829 kWh for the household and an additional 4993 kWh for the heat pump. The dataset can support the understanding of patterns in electrical load curves and can help to estimate the additional load on distribution networks induced by heat pumps.

Effects of Fasting and Lifestyle Modification in Patients with Metabolic Syndrome: A Randomized Controlled Trial.

BACKGROUND: Lifestyle interventions, such as fasting, diet, and exercise, are increasingly used as a treatment option for patients with metabolic syndrome (MS). This study assesses the efficacy and safety of fasting followed by lifestyle modification in patients with MS compared to lifestyle modification only. METHODS: Single-blind, multicenter, parallel, randomized controlled trial in two German tertiary referral hospitals in metropolitan areas. INTERVENTIONS: (a) 5-day fasting followed by 10 weeks of lifestyle modification (modified DASH diet, exercise, mindfulness; n = 73); (b) 10 weeks of lifestyle modification only (n = 72). MAIN OUTCOMES AND MEASURES: Co-primary outcomes were ambulatory systolic blood pressure and the homeostasis model assessment (HOMA) index at week 12. Further outcomes included anthropometric, laboratory parameters, and the PROCAM score at weeks 1, 12, and 24. RESULTS: A total of 145 patients with metabolic syndrome (62.8% women; 59.7 ± 9.3 years) were included. No significant group differences occurred for the co-primary outcomes at week 12. However, compared to lifestyle modification only, fasting significantly reduced HOMA index (Δ = -0.8; 95% confidence interval [CI] = -1.7, -0.1), diastolic blood pressure (Δ = -4.8; 95% CI = -5.5, -4.1), BMI (Δ = -1.7; 95% CI = -2.0, -1.4), weight (Δ = -1.7; 95% CI = -2.0, -1.4), waist circumference (Δ = -2.6; 95% CI = -5.0, -0.2), glucose (Δ = -10.3; 95% CI = -19.0, -1.6), insulin (Δ = -2.9; 95% CI = -5.3, -0.4), HbA1c (Δ = -0.2; 95% CI = -0.4, -0.05;), triglycerides (Δ = -48.9; 95% CI = -81.0, -16.9), IL-6 (Δ = -1.2; 95% CI = -2.5, -0.005), and the 10-year risk of acute coronary events (Δ = -4.9; 95% CI = -9.5, -0.4) after week 1. Fasting increased uric acid levels (Δ = 1.0; 95% CI = 0.1, 1.9) and slightly reduced eGRF (Δ = -11.9; 95% CI = -21.8, -2.0). Group differences at week 24 were found for weight (Δ = -2, 7; 95% CI = -4.8, -0.5), BMI (Δ = -1.0; 95% CI = -1.8, -0.3), glucose (Δ = -7.7; 95% CI = -13.5, -1.8), HDL (Δ = 5.1; 95% CI = 1.5, 8.8), and CRP (Δ = 0.2; 95% CI = 0.03, 0.4). No serious adverse events occurred. CONCLUSIONS: A beneficial effect at week 24 was found on weight; fasting also induced various positive short-term effects in patients with MS. Fasting can thus be considered a treatment for initializing lifestyle modification for this patient group; however, it remains to be investigated whether and how the multilayered effects of fasting can be maintained in the medium and longer term.

A Randomized Controlled Trial of Fasting and Lifestyle Modification in Patients with Metabolic Syndrome: Effects on Patient-Reported Outcomes.

Lifestyle interventions can have a positive impact on quality of life and psychological parameters in patients with metabolic syndrome (MetS). In this randomized controlled trial, 145 participants with MetS (62.8% women; 59.7 ± 9.3 years) were randomized to (1) 5-day fasting followed by 10 weeks of lifestyle modification (F + LM; modified DASH diet, exercise, mindfulness; n = 73) or (2) 10 weeks of lifestyle modification only (LM; n = 72). Outcomes were assessed at weeks 0, 1, 12, and 24, and included quality of life (Short-Form 36 Health Survey Questionnaire, SF-36), anxiety/depression (Hospital Anxiety and Depression Scale, HADS), stress (Cohen Perceived Stress Scale, CPSS), mood (Profile of Mood States, POMS), self-efficacy (General Self-Efficacy Scale, GSE), mindfulness (Mindfulness Attention Awareness Scale, MAAS), and self-compassion (Self-Compassion Scale, SCS). At week 1, POMS depression and fatigue scores were significantly lower in F + LM compared to LM. At week 12, most self-report outcomes improved in both groups-only POMS vigor was significantly higher in F + LM than in LM. Most of the beneficial effects within the groups persisted at week 24. Fasting can induce mood-modulating effects in the short term. LM induced several positive effects on quality of life and psychological parameters in patients with MetS.