Chemical imaging reveals diverse functions of tricarboxylic acid metabolites in root growth and development.

Understanding how plants grow is critical for agriculture and fundamental for illuminating principles of multicellular development. Here, we apply desorption electrospray ionization mass spectrometry imaging (DESI-MSI) to the chemical mapping of the developing maize root. This technique reveals a range of small molecule distribution patterns across the gradient of stem cell differentiation in the root. To understand the developmental logic of these patterns, we examine tricarboxylic acid (TCA) cycle metabolites. In both Arabidopsis and maize, we find evidence that elements of the TCA cycle are enriched in developmentally opposing regions. We find that these metabolites, particularly succinate, aconitate, citrate, and α-ketoglutarate, control root development in diverse and distinct ways. Critically, the developmental effects of certain TCA metabolites on stem cell behavior do not correlate with changes in ATP production. These results present insights into development and suggest practical means for controlling plant growth.

SDHB knockout and succinate accumulation are insufficient for tumorigenesis but dual SDHB/NF1 loss yields SDHx-like pheochromocytomas.

Inherited pathogenic succinate dehydrogenase (SDHx) gene mutations cause the hereditary pheochromocytoma and paraganglioma tumor syndrome. Syndromic tumors exhibit elevated succinate, an oncometabolite that is proposed to drive tumorigenesis via DNA and histone hypermethylation, mitochondrial expansion, and pseudohypoxia-related gene expression. To interrogate this prevailing model, we disrupt mouse adrenal medulla SDHB expression, which recapitulates several key molecular features of human SDHx tumors, including succinate accumulation but not 5hmC loss, HIF accumulation, or tumorigenesis. By contrast, concomitant SDHB and the neurofibromin 1 tumor suppressor disruption yields SDHx-like pheochromocytomas. Unexpectedly, in vivo depletion of the 2-oxoglutarate (2-OG) dioxygenase cofactor ascorbate reduces SDHB-deficient cell survival, indicating that SDHx loss may be better tolerated by tissues with high antioxidant capacity. Contrary to the prevailing oncometabolite model, succinate accumulation and 2-OG-dependent dioxygenase inhibition are insufficient for mouse pheochromocytoma tumorigenesis, which requires additional growth-regulatory pathway activation.

Cell-Based Ambient Venturi Autosampling and Matrix-Assisted Laser Desorption Ionization Mass Spectrometric Imaging of Secretory Products.

A cell-based ambient Venturi autosampling device was established for the monitoring of dynamic cell secretions in response to chemical stimulations in real time with temporal resolution on the order of a second. Detection of secretory products of cells and screening of bioactive compounds are primarily performed on an ambient autosampling probe and matrix-assisted laser desorption ionization (MALDI) mass spectrometry. It takes advantage of the Venturi effect in which the fluid flowing through an inlet capillary tube is automatically fed into a parallel array of multiple outlet capillaries. Cells are incubated inside the inlet capillary tube that is connected with either a syringe pump or liquid chromatography (LC) for the transfer of single compounds or mixtures, respectively. Secretory products were continuously pushed into the outlet capillaries and then spotted into a compressed thin film of the matrix material 9-aminoacridine for MALDI mass spectrometric imaging. In physiological pH, without the use of high voltages and without the use of chemical derivatizations, this platform can be applied to the direct assay of neurotransmitters or other secretory products released from cells in response to the stimulation of individual compounds or LC-separated eluates of natural mixtures. It provides a new way to identify bioactive compounds with a detection limit down to 0.04 fmol/pixel.

Adipocytes Provide Fatty Acids to Acute Lymphoblastic Leukemia Cells.

BACKGROUND: There is increasing evidence that adipocytes play an active role in the cancer microenvironment. We have previously reported that adipocytes interact with acute lymphoblastic leukemia (ALL) cells, contributing to chemotherapy resistance and treatment failure. In the present study, we investigated whether part of this resistance is due to adipocyte provision of lipids to ALL cells. METHODS: We cultured 3T3-L1 adipocytes, and tested whether ALL cells or ALL-released cytokines induced FFA release. We investigated whether ALL cells took up these FFA, and using fluorescent tagged BODIPY-FFA and lipidomics, evaluated which lipid moieties were being transferred from adipocytes to ALL. We evaluated the effects of adipocyte-derived lipids on ALL cell metabolism using a Seahorse XF analyzer and expression of enzymes important for lipid metabolism, and tested whether these lipids could protect ALL cells from chemotherapy. Finally, we evaluated a panel of lipid synthesis and metabolism inhibitors to determine which were affected by the presence of adipocytes. RESULTS: Adipocytes release free fatty acids (FFA) when in the presence of ALL cells. These FFA are taken up by the ALL cells and incorporated into triglycerides and phospholipids. Some of these lipids are stored in lipid droplets, which can be utilized in states of fuel deprivation. Adipocytes preferentially release monounsaturated FFA, and this can be attenuated by inhibiting the desaturating enzyme steroyl-CoA decarboxylase-1 (SCD1). Adipocyte-derived FFA can relieve ALL cell endogenous lipogenesis and reverse the cytotoxicity of pharmacological acetyl-CoA carboxylase (ACC) inhibition. Further, adipocytes alter ALL cell metabolism, shifting them from glucose to FFA oxidation. Interestingly, the unsaturated fatty acid, oleic acid, protects ALL cells from modest concentrations of chemotherapy, such as those that might be present in the ALL microenvironment. In addition, targeting lipid synthesis and metabolism can potentially reverse adipocyte protection of ALL cells. CONCLUSION: These findings uncover a previously unidentified interaction between ALL cells and adipocytes, leading to transfer of FFA for use as a metabolic fuel and macromolecule building block. This interaction may contribute to ALL resistance to chemotherapy, and could potentially be targeted to improve ALL treatment outcome.

First Line CombinAtion Therapy in the Treatment of Stage II and III Hypertension (FLASH).

Background: Lowering blood pressure (BP) leads to reduced risk of stroke, myocardial infarction, and cardiovascular mortality. Single-pill combination therapies may deliver better BP control than increasing the dose of monotherapies or using more drugs separately. Objectives: The aim of the present observational study was to investigate the real-life use and the effect of first line or replacement single-pill combination therapies containing irbesartan and hydrochlorothiazide (HCTZ) on systolic BP (SBP) control rate in patients with hypertension. Methods: Overall, 780 patients with moderate or severe hypertension either untreated (289; 37%) or uncontrolled (491; 63%) with previous therapy were included in the "First Line CombinAtion Therapy in the Treatment of Stage II and III Hypertension" (FLASH) prospective Swiss national-wide cohort study. All recruited patients received single-pill antihypertensive combination therapy containing HCTZ and irbesartan. BP was measured at baseline and after 8-weeks follow-up according to guidelines. Results: Mean reductions in office systolic/diastolic BP (SBP/DBP) were 23.7 ± 13.7/11.7 ± 8.5 mmHg, with reductions of 26.9 ± 14.1/13.0 ± 8.8 mmHg or 21.8 ± 13.1/11.0 ± 8.3 mmHg when the single-pill combination of irbesartan/HCTZ was given as first line or replacement treatment, respectively (p < 0.001 for differences between first line and replacement treatment in both SBP and DBP). The guidelines-recommended goals were reached in 368 (47%), 492 (63%), and 312 (40%) patients for SBP, DBP, and SBP/DBP, respectively. The SBP control rate was higher when the combination was used as first line treatment (52 vs. 44%; p = 0.043). Overall, 145 adverse events were recorded; hypotension in 12 (1.5%) cases, hypokalaemia in 9 (1.2%), and hyperkalaemia in 3 (0.4%). Conclusions: The single-pill combination of irbesartan/HCTZ was well-tolerated and achieved substantial reductions in both systolic and diastolic BP. The SBP control rate was greater when the combination was prescribed as first line treatment as suggested by recent ESC/ESH guidelines.

Nanoparticles decorated with granulocyte-colony stimulating factor for targeting myeloid cells.

Dysregulated myeloid cell activity underlies a variety of pathologies, including immunosuppression in malignant cancers. Current treatments to alter myeloid cell behavior also alter other immune cell subpopulations and nonimmune cell types with deleterious side effects. Therefore, improved selectivity of myeloid treatment is an urgent need. To meet this need, we demonstrate a novel, targeted nanoparticle system that achieves superior myeloid selectivity both in vitro and in vivo. This system comprises: (1) granulocyte-colony stimulating factor (G-CSF) as a targeting ligand to promote accumulation in myeloid cells, including immunosuppressive myeloid-derived suppressor cells (MDSCs); (2) albumin nanoparticles 100-120 nm in diameter that maintain morphology and drug payload in simulated physiological conditions; and (3) a fluorophore that enables nanoparticle tracking and models a therapeutic molecule. Here, we show that this strategy achieves high myeloid uptake in mixed primary immune cells and that nanoparticles successfully infiltrate the 4T1 triple-negative breast tumor murine microenvironment, where they preferentially accumulate in myeloid cells in a mouse model. Further development will realize diagnostic myeloid cell tracking applications and therapeutic delivery of myeloid-reprogramming drugs.

Effect of Home Blood Pressure Monitoring on Patient's Awareness and Goal Attainment Under Antihypertensive Therapy: The Factors Influencing Results in Anti-HypertenSive Treatment (FIRST) Study.

BACKGROUND/AIMS: Despite availability of a broad spectrum of blood pressure (BP)-lowering drugs many hypertensive patients do not attain BP goals. We aimed to evaluate the influence of home blood pressure monitoring (HBPM) on patient's awareness and attainment of BP goals under antihypertensive treatment with irbesartan alone or in combination with hydro-chlorothiazide. METHODS: In total, 1,268 patients with arterial hypertension were enrolled in the Factors Influencing Results in anti-hypertenSive Treatment (FIRST) study by 348 general practitioners and internal medicine specialists across Switzerland. Patients selected for HBPM received detailed information and training on BP self-management. The study endpoints included patient's awareness and attainment of BP goals, and the efficacy and tolerability of antihypertensive treatment at 3 months. RESULTS: Overall, the mean age was 61±13 years and 616 (49%) were women. The mean systolic/diastolic BP was 161±17/96±11 mmHg, and 239 (19%) patients had diabetes mellitus. 758 (60%) patients were instructed to use HBPM. Both the proportion of patients aware of their BP goals (81% vs. 70%; p< 0.001) and the percentage of patients reaching their BP goal (64% vs. 57%; p=0.028) were higher in those with vs. without HBPM. The mean reduction in systolic/diastolic BP was 23.8/13.2 mmHg. Only 35 (3.0%) patients discontinued antihypertensive therapy. CONCLUSION: In a large Swiss cohort of patients with arterial hypertension, information and training on BP self-measurement and direct involvement of patients by using HBPM led to improvement in BP control. Treatment with irbesartan alone or in combination with hydrochlorothiazide was well tolerated and markedly reduced BP.

Analytical Capability of Defocused µ-SORS in the Chemical Interrogation of Thin Turbid Painted Layers.

A recently developed micrometer-scale spatially offset Raman spectroscopy (µ-SORS) method provides a new analytical capability for investigating non-destructively the chemical composition of sub-surface, micrometer-scale thickness, diffusely scattering layers at depths beyond the reach of conventional confocal Raman microscopy. Here, we demonstrate experimentally, for the first time, the capability of µ-SORS to determine whether two detected chemical components originate from two separate layers or whether the two components are mixed together in a single layer. Such information is important in a number of areas, including conservation of cultural heritage objects, and is not available, for highly turbid media, from conventional Raman microscopy, where axial (confocal) scanning is not possible due to an inability to facilitate direct imaging within the highly scattering sample. This application constitutes an additional capability for µ-SORS in addition to its basic capacity to determine the overall chemical make-up of layers in a turbid system.

Knee Extension Range of Motion at 4 Weeks Is Related to Knee Extension Loss at 12 Weeks After Anterior Cruciate Ligament Reconstruction.

BACKGROUND: The anterior cruciate ligament (ACL) is commonly torn, and surgical reconstruction is often required to allow a patient to return to their prior level of activity. Avoiding range of motion (ROM) loss is a common goal, but little research has been done to identify when ROM loss becomes detrimental to a patient's future function. PURPOSE: To determine whether there is a relationship between early knee side-to-side extension difference after ACL reconstruction and knee side-to-side extension difference at 12 weeks. The hypothesis was that early (within the first 8 weeks) knee side-to-side extension difference will be predictive of knee side-to-side extension difference seen at 12 weeks. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Knee side-to-side extension difference measures were taken on 74 patients undergoing ACL reconstruction rehabilitation at the initial visit and 4, 8, and 12 weeks postoperatively. Visual analog scores (VAS) and International Knee Documentation Committee (IKDC) scores were also recorded at these time frames. RESULTS: There was a strong relationship between knee extension ROM at 4 and 12 weeks (r = 0.639, P < .001) and 8 and 12 weeks (r = 0.742, P < .001). When the variables of knee extension ROM at initial visit and 4 and 8 weeks were entered into a regression analysis, the predictor variable explained 61% (R (2) = 0.611) of variance for knee extension ROM at 12 weeks, with 4 weeks (R (2) = 0.259) explaining the majority of this variance. CONCLUSION: This study found that a patient's knee extension at 4 weeks was strongly correlated with knee extension at 12 weeks. CLINICAL RELEVANCE: This information may be useful for clinicians treating athletic patients who are anxious for return to sport by providing them an initial goal to work toward in hopes of ensuring successful rehabilitation of their knee.

Direct oral anticoagulants in atrial fibrillation.

Atrial fibrillation (AF), the most frequent sustained arrhythmia, is associated with an increased risk of thromboembolic events. The risk of stroke depends on risk factors such as age, hypertension, heart failure, and vascular disease. Thus, antithrombotic therapy is a cornerstone in the management of AF. Warfarin is successfully used to reduce thromboembolic events. More recently, direct thrombin (dabigatran) and factor Xa (apixaban, edoxaban, rivaroxaban) inhibitors have been compared to warfarin in large randomized trials. All new substances have been shown to be non-inferior to warfarin concerning thromboembolic events. Severe bleeding, such as fatal and intracranial bleeding, was less frequent with direct oral anticoagulants. Results of the studies and subgroup analyses are discussed. Further trials using direct oral anticoagulants in special populations such as very old and patients with kidney disease are needed.