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Objective CD8+ T cells contribute to rheumatoid arthritis (RA) by releasing proinflammatory and cytolytic mediators, even in a challenging hypoxic and nutrient‐poor microenvironment such as the synovial membrane. This study was undertaken to explore the mechanisms through which CD8+ T cells meet their metabolic demands in the blood and synovial membrane of patients with RA. Methods Purified blood CD8+ T cells from patients with RA, patients with psoriatic arthritis (PsA), and patients with spondyloarthritis (SpA), as well as healthy control subjects, and CD8+ T cells from RA synovial membrane were stimulated in medium containing 13C‐labeled metabolic substrates in the presence or absence of metabolic inhibitors, under conditions of normoxia or hypoxia. The production of metabolic intermediates was quantified by 1H‐nuclear magnetic resonance. The expression of metabolic enzymes, transcription factors, and immune effector molecules was assessed at both the messenger RNA (mRNA) and protein levels. CD8+ T cell functional studies were performed. Results RA blood CD8+ T cells met their metabolic demands through aerobic glycolysis, production of uniformly 13C‐enriched lactate in the RA blood (2.6 to 3.7–fold higher than in patients with SpA, patients with PsA, and healthy controls; P < 0.01), and induction of glutaminolysis. Overexpression of Warburg effect–linked enzymes in all RA CD8+ T cell subsets maintained this metabolic profile, conferring to the cells the capacity to proliferate under hypoxia and low‐glucose conditions. In all RA CD8+ T cell subsets, lactate dehydrogenase A (LDHA) was overexpressed at the mRNA level (P < 0.03 versus controls; n = 6 per group) and protein level (P < 0.05 versus controls; n = 17 RA patients, n = 9 controls). In RA blood, inhibition of LDHA with FX11 led to reductions in lipogenesis, migration and proliferation of CD8+ T cells, and CD8+ T cell effector functions, while production of reactive oxygen species was increased by 1.5‐fold (P < 0.03 versus controls). Following inhibition of LDHA with FX11, RA CD8+ T cells lost their capacity to induce healthy B cells to develop a proinflammatory phenotype. Similar metabolic alterations were observed in RA CD8+ T cells from the synovial membrane. Conclusion Remodeling glucose and glutamine metabolism in RA CD8+ T cells by targeting LDHA activity can reduce the deleterious inflammatory and cytolytic contributions of these cells to the development of autoimmunity.

The mammalian circadian clock and the cell cycle are two major biological oscillators whose coupling influences cell fate decisions. In the present study, we use a model-driven experimental approach to investigate the interplay between clock and cell cycle components and the dysregulatory effects of RAS on this coupled system. In particular, we focus on the Ink4a/Arf locus as one of the bridging clock-cell cycle elements. Upon perturbations by the rat sarcoma viral oncogene (RAS), differential effects on the circadian phenotype were observed in wild-type and Ink4a/Arf knock-out mouse embryonic fibroblasts (MEFs), which could be reproduced by our modelling simulations and correlated with opposing cell cycle fate decisions. Interestingly, the observed changes can be attributed to in silico phase shifts in the expression of core-clock elements. A genome-wide analysis revealed a set of differentially expressed genes that form an intricate network with the circadian system with enriched pathways involved in opposing cell cycle phenotypes. In addition, a machine learning approach complemented by cell cycle analysis classified the observed cell cycle fate decisions as dependent on Ink4a/Arf and the oncogene RAS and highlighted a putative fine-tuning role of Bmal1 as an elicitor of such processes, ultimately resulting in increased cell proliferation in the Ink4a/Arf knock-out scenario. This indicates that the dysregulation of the core-clock might work as an enhancer of RAS-mediated regulation of the cell cycle. Our combined in silico and in vitro approach highlights the important role of the circadian clock as an Ink4a/Arf-dependent modulator of oncogene-induced cell fate decisions, reinforcing its function as a tumour-suppressor and the close interplay between the clock and the cell cycle network.

The circadian clock is a powerful endogenous timing system, which allows organisms to fine-tune their physiology and behaviour to the geophysical time. The interplay of a distinct set of core-clock genes and proteins generates oscillations in expression of output target genes which temporally regulate numerous molecular and cellular processes. The study of the circadian timing at the organismal as well as at the cellular level outlines the field of chronobiology, which has been highly interdisciplinary ever since its origins. The development of high-throughput approaches enables the study of the clock at a systems level. In addition to experimental approaches, computational clock models exist which allow the analysis of rhythmic properties of the clock network. Such mathematical models aid mechanistic understanding and can be used to predict outcomes of distinct perturbations in clock components, thereby generating new hypotheses regarding the putative function of particular clock genes. Perturbations in the circadian timing system are linked to numerous molecular dysfunctions and may result in severe pathologies including cancer. A comprehensive knowledge regarding the mechanistic of the circadian system is crucial to develop new procedures to investigate pathologies associated with a deregulated clock.In this manuscript we review the combination of experimental methodologies, bioinformatics and theoretical models that have been essential to explore this remarkable timing-system. Such an integrative and interdisciplinary approach may provide new strategies with regard to chronotherapeutic treatment and new insights concerning the restoration of the circadian timing in clock-associated diseases.

By regulating the timing of cellular processes, the circadian clock provides a way to adapt physiology and behaviour to the geophysical time. In mammals, a light-entrainable master clock located in the suprachiasmatic nucleus (SCN) controls peripheral clocks that are present in virtually every body cell. Defective circadian timing is associated with several pathologies such as cancer and metabolic and sleep disorders. To better understand the circadian regulation of cellular processes, we developed a bioinformatics pipeline encompassing the analysis of high-throughput data sets and the exploitation of published knowledge by text-mining. We identified 118 novel potential clock-regulated genes and integrated them into an existing high-quality circadian network, generating the to-date most comprehensive network of circadian regulated genes (NCRG). To validate particular elements in our network, we assessed publicly available ChIP-seq data for BMAL1, REV-ERBα/β and RORα/γ proteins and found strong evidence for circadian regulation of Elavl1, Nme1, Dhx6, Med1 and Rbbp7 all of which are involved in the regulation of tumourigenesis. Furthermore, we identified Ncl and Ddx6, as targets of RORγ and REV-ERBα, β, respectively. Most interestingly, these genes were also reported to be involved in miRNA regulation; in particular, NCL regulates several miRNAs, all involved in cancer aggressiveness. Thus, NCL represents a novel potential link via which the circadian clock, and specifically RORγ, regulates the expression of miRNAs, with particular consequences in breast cancer progression. Our findings bring us one step forward towards a mechanistic understanding of mammalian circadian regulation, and provide further evidence of the influence of circadian deregulation in cancer.

Highlights The role of miRNAs in PAH is fast expanding, and it is increasingly difficult to identify which molecules have the highest translational potential. This review discusses the challenges in miRNA analysis and interpretation in PAH and highlights 4 promising miRNAs in this field. Additional pre-clinical studies and clinical trials are urgently needed to bring miRNAs from the bench to the bedside soon.

Type 2 diabetes mellitus (T2DM) is a major risk factor for several cardiovascular (CV) conditions, including heart failure (HF). However, until recently, no therapy to treat patients with diabetes could also reduce CV risks related to HF. The EMPA-REG OUTCOME trial with empagliflozin was the first to demonstrate significant cardioprotective benefits in this population. Its impressive 35% reduction in hospitalizations for HF drew the attention of the scientific community to the possibility that pharmacologic sodium-glucose cotransporter 2 (SGLT2) inhibition could be part of the armamentarium for treating patients with HF, with and without diabetes. The recently published CANVAS Program (with canagliflozin) and real-life data from the CVD-Real Study (using dapagliflozin, empagliflozin, and canagliflozin) further strengthened this hypothesis, suggesting that the observed benefit is not restricted to a particular drug, but is rather a class effect. This review explores the effects of pharmacologic SGLT2 inhibitors' use in cardiac function and discusses the potential role of this class of medication as a treatment for HF.

ObjectiveMedication adherence is impacted by regimen complexity. The SIMPLE (Simple basal Insulin titration, Metformin Plus Liraglutide for type 2 diabetes with very Elevated HbA1c) study compared GLP1RA plus basal insulin (GLP1RA+BI) to basal-bolus insulin (BBI) regimen in participants with very uncontrolled type 2 diabetes mellitus (T2DM). This analysis aimed to evaluate medication adherence to GLP1RA+BI compared with BBI, the effect of adherence on clinical and patient-reported outcomes, and baseline predictors of adherence.Research design and methodsThis was an analysis of the SIMPLE study based on prespecified outcome. The study took place in pragmatic, real-world setting. A total of 120 adults with T2DM and HgbA1c≥10% were randomized to detemir plus liraglutide, or detemir plus aspart before each meal; 6-month follow-up. The main outcomes evaluated were: adherence, HgbA1c, weight, quality of life, and hypoglycemia. Adherence rate was calculated for each study medication at each follow-up visit; participants were classified as ≥80% or <80% adherent.ResultA higher percentage of participants in the GLP1RA+BI compared with the BBI group had ≥80% adherence to detemir (59.3% vs 35.7%, p=0.02) as well as liraglutide versus aspart (57.4% vs 30.4%, p=0.007). Higher age was predictive of ≥80% adherence (OR per 5-year increment=1.48, 95% CI 1.09 to 2.0, p=0.01). Higher adherence led to greater improvement in HbA1c and weight in both groups. Treatment with GLP1RA+BI compared with BBI led to greater improvement in HbA1c, weight, and quality of life and lower risk of hypoglycemia even after adjusting for the difference in adherence between groups.ConclusionsAdherence was higher with the simplified regimen of GLP1RA+BI compared with BBI. Greater adherence to the simpler regimen amplified the treatment effect on HbA1c, weight, quality of life, and risk of hypoglycemia, yet statistically significant greater benefits were noted even when adjusted for adherence.Trial registration numberNCT01966978