Escherichia coli Dcu C4-dicarboxylate transporters dependent proton and potassium fluxes and FOF1-ATPase activity during glucose fermentation at pH 7.5

During fermentation in Escherichia coli succinate is transported via Dcu transporters, encoded dcuA, dcuB, dcuC and dcuD although the role of DcuD protein has not been elucidated yet. It has been shown contribution of Dcu transporters in the N,N'-dicyclohexylcarbodiimide (DCCD) sensitive proton and potassium transport through the cytoplasmic membrane and membrane-associated ATPase activity. Total H^± efflux was decreased ~ 40% while K^± uptake was absent in dcuD mutant. DCCD-sensitive H^± flux was absent in dcuD nevertheless it was increased ~ 3 fold in dcuACB. K^± uptake in dcuACB was stimulated ~ 30% compared to wild type but in DCCD assays K^± ions were effluxed with the rate of 0.15 mmol/min per 10⁹ cells/ml. In dcuACB mutant membrane potential (ΔΨ) was ~ 30 mV higher than in wild type. dcuD gene expression was increased in the dcuACB mutant respect to wild type at pH 7.5 (~120%), suggesting that an increment of DcuD activity compensates the lack of DcuA, DcuC and DcuB carriers. It can be concluded that active DcuD is important for H^± efflux via the F_OF₁-ATPase and K^± uptake at pH 7.5. In addition, DcuA, DcuB and DcuC transporters are crucial for regulating DCCD-sensitive K^± transport and ΔΨ in E. coli.

Evidence for Escherichia coli DcuD carrier dependent FOF1-ATPase activity during fermentation of glycerol

During fermentation Escherichia coli excrete succinate mainly via Dcu family carriers. Current work reveals the total and N,N'-dicyclohexylcarbodiimide (DCCD) inhibited ATPase activity at pH 7.5 and 5.5 in E. coli wild type and dcu mutants upon glycerol fermentation. The overall ATPase activity was highest at pH 7.5 in dcuABCD mutant. In wild type cells 50% of the activity came from the FOF1-ATPase but in dcuD mutant it reached ~80%. K+ (100 mM) stimulate total but not DCCD inhibited ATPase activity 40% and 20% in wild type and dcuD mutant, respectively. 90% of overall ATPase activity was inhibited by DCCD at pH 5.5 only in dcuABC mutant. At pH 7.5 the H+ fluxes in E. coli wild type, dcuD and dcuABCD mutants was similar but in dcuABC triple mutant the H+ flux decreased 1.4 fold reaching 1.15 mM/min when glycerol was supplemented. In succinate assays the H+ flux was higher in the strains where DcuD is absent. No significant differences were determined in wild type and mutants specific growth rate except dcuD strain. Taken together it is suggested that during glycerol fermentation DcuD has impact on H+ fluxes, FOF1-ATPase activity and depends on potassium ions.

[Iron deficiency in Russia heart failure patients. Observational cross-sectional multicenter study]

Aim    To evaluate the prevalence of iron deficiency (ID) in Russian patients with heart failure (HF).Material and methods    Iron metabolism variables were studied in 498 (198 women, 300 men) patients with HF. Data were evaluated at admission for HF (97 %) or during an outpatient visit (3 %). ID was determined according to the European Society of Cardiology Guidelines.Results    83.1 % of patients had ID; only 43.5 % of patients with ID had anemia. Patients with ID were older: 70.0 [63.0;79.0] vs. 66.0 years [57.0;75.2] (p=0.009). The number of patients with ID increased in parallel with the increase in HF functional class (FC). Among patients with ID, fewer people were past or current alcohol users (p=0.002), and a greater number of patients had atrial fibrillation (60.1 vs. 45.2 %, p=0.016). A multiple logistic regression showed that more severe HF (HF FC) was associated with a higher incidence of ID detection, whereas past alcohol use was associated with less pronounced ID. An increase in N-terminal pro-brain natriuretic peptide (NT-proBNP) by 100 pg/ml was associated with an increased likelihood of ID (odds ratio, 1.006, 95 % confidence interval: 1.002-1.011, p=0.0152).Conclusion    The incidence rate of HF patients is high in the Russian Federation (83.1 %). Only 43.5 % of these patients had anemia. The prevalence of ID in the study population increased with increases in HF FC and NT-proBNP.

Association of Inflammasome Gene Expression Levels with Pathogenesis of Familial Mediterranean Fever in Armenians

Familial Mediterranean fever (FMF) is a genetically determined autoinflammatory disease transmitted mostly by an autosomal recessive mechanism and caused by point mutations of the MEFV (Mediterranean FeVer) gene. The aim of this study was to evaluate the expression of inflammasome genes (p65, Casp1, MEFV, and NLRP3) in patients with FMF compared to controls to understand the changes playing a key role in disease development. We found altered expression levels of the full-length MEFV isoform as well as Casp1 and p65 in FMF patients versus controls. This, once again, highlighted the significance of inflammasome genes in terms of FMF.

Generation of iPSCs from a Patient with the M694V Mutation in the MEFV Gene Associated with Familial Mediterranean Fever and Their Differentiation into Macrophages

Familial Mediterranean fever (FMF) is a systemic autoinflammatory disorder caused by inherited mutations in the MEFV (Mediterranean FeVer) gene, located on chromosome 16 (16p13.3) and encoding the pyrin protein. Despite the existing data on MEFV mutations, the exact mechanism of their effect on the development of the pathological processes leading to the spontaneous and recurrent autoinflammatory attacks observed in FMF, remains unclear. Induced pluripotent stem cells (iPSCs) are considered an important tool to study the molecular genetic mechanisms of various diseases due to their ability to differentiate into any cell type, including macrophages, which contribute to the development of FMF. In this study, we developed iPSCs from an Armenian patient with FMF carrying the M694V, p.(Met694Val) (c.2080A>G, rs61752717) pathogenic mutation in exon 10 of the MEFV gene. As a result of direct differentiation, macrophages expressing CD14 and CD45 surface markers were obtained. We found that the morphology of macrophages derived from iPSCs of a patient with the MEFV mutation significantly differed from that of macrophages derived from iPSCs of a healthy donor carrying the wild-type MEFV gene.

In Search of Optimal Criteria for Iron Deficiency in CHF Patients. Post-hoc Analysis of the Study "Prevalence of Iron Deficiency in Patients With Chronic Heart Failure in the Russian Federation (ID-CHF-RF)"

AIM

Comparative analysis of clinical, anamnestic, and laboratory and instrumental data of patients with chronic heart failure (CHF) and iron deficiency (ID) diagnosed according to the AHA/ESC/RSC criteria, and CHF patients diagnosed with ID based on decreased transferrin saturation (TSAT) ≤19.8% or serum iron (Fe) ≤13 μmol/l.

MATERIAL AND METHODS

An additional analysis of the ID-CHF-RF study was performed. The analyzed population included 498 patients (198 women) with CHF. In addition to the ID criteria provided by the protocol (AHA/ESC/RSC criteria: ferritin <100 μg/l or ferritin from 100 to 299 μg/l and TSAT<20%), concentrations of ID biomarkers were assessed, which showed high sensitivity and specificity for the diagnosis of ID compared to the morphological picture of the bone marrow (TSAT<19.8% or Fe ≤13 μmol/l). Subgroups of patients with ID determined only by the AHA/ESC/RSC criteria, only by the TSAT≤19.8% and Fe ≤13 μmol/l criteria, and by both were analyzed.

RESULTS

ID diagnosed by the AHA/ESC/RSC criteria was found in 83.1% of patients. The TSAT ≤19.8% and Fe ≤13 μmol/l criteria revealed ID in 74.5% of patients. In 341 patients (76.8%), ID was diagnosed using both criteria. Patients with ID diagnosed by the TSAT≤19.8% and Fe≤13 μmol/l criteria, compared with patients with ID diagnosed by the AHA/ESC/RKO criteria, had a 50% lower Fe (9.8 μmol/l vs. 19.4 μmol/l) and a higher incidence of anemia (43.3% vs. 23.3%) and diabetes mellitus (DM) (36.7% and 24.7%). Also, these patients had higher values of body mass index (BMI) and NT-proBNP concentration (2317 [1305;9092] vs. 1691 [709;3856] pg/ml), and lower LV EF values (41.5 [29.0;54.5]% vs. 45.0 [34.0;54.0]%), respectively. The most severe course of CHF and the greatest changes in laboratory tests associated with ID and anemia were observed in patients with ID determined by two criteria. Patients in this group were older, with a higher BMI, more frequent presence of atrial fibrillation, and higher NT-proBNP (4182 [1854;9341] pg/ml).

CONCLUSION

Patients with isolated low ferritin are characterized by less severe clinical and functional impairment compared to patients with low TSAT or Fe. At the same time, patients with ferritin higher than 300 μg/l and low TSAT and/or Fe were characterized by very severe CHF and a low functional status, although this may not be related with ID. Thus, the use of the ferritin-based criteria of ID may lead to overdiagnosis of ID in some patients and, at the same time, miss some of the most "severe" patients who likely require the ID correction. Patients with ID who show a decrease in all three parameters are likely to benefit most from Fe supplementation. It is advisable to perform additional studies on the effect of Fe supplements on the course and prognosis of the disease in this cohort of patients.

Effectiveness of indapamide/amlodipine single-pill combination in patients with isolated systolic hypertension: post-hoc analysis of the ARBALET study

BACKGROUND

This study evaluated the effectiveness of treatment with an indapamide/amlodipine single-pill combination (SPC) in outpatients with uncontrolled isolated systolic hypertension (ISH) aged over 55 years in real-life clinical practice.

METHODS

This was a post-hoc analysis of the subgroup of patients with ISH from ARBALET, a 3-month, multicenter, observational, open-label study conducted in Russia among patients with grade I or II hypertension who were either uncontrolled on previous antihypertensive treatment or treatment-naïve. The effectiveness of indapamide/amlodipine SPC was assessed by the change in office systolic blood pressure (SBP) and the rate of target SBP (< 140 mmHg) achievement at 2 weeks, 1 month and 3 months, in four age groups: 55-59 years, 60-69 years, 70-79 years, and 80 years or older.

RESULTS

The ARBALET study recruited 2217 patients, of whom 626 had ISH and were included in this post-hoc analysis (mean age 66.1 ± 7.8 years; 165 men [26.4%] and 461 women [73.6%]). Target SBP < 140 mmHg was achieved in 43%, 75% and 93% of patients at 2 weeks, 1 and 3 months, respectively. SBP decreased from baseline by 18.8 ± 10.5 mmHg, 27.2 ± 10.6 mmHg and 31.8 ± 9.9 mmHg at 2 weeks, 1 month and 3 months, respectively. In the groups of patients aged 55-59, 60-69, 70-79, and ≥ 80 years, SBP reductions at 3 months compared with baseline were - 30.3 ± 9.4, - 32.4 ± 9.7, - 32.5 ± 10.7, and - 28.9 ± 9.6 mmHg, respectively.

CONCLUSION

This post-hoc analysis of the observational ARBALET study showed that indapamide/amlodipine SPC was associated with significant reductions in BP and high rates of target BP achievement in a broad age range of patients with ISH treated in routine clinical practice.

STUDY REGISTRATION NUMBER

ISRCTN40812831.

Female and Male Phenotypes of Iron Deficiency in CHF. Additional analysis of the «The Prevalence of Iron Deficiency in Patients With Chronic Heart Failure in the Russian Federation (J-CHF-RF)» study

Aim    To evaluate the incidence of iron deficiency (ID) in men and women with chronic heart failure (CHF) and to compare clinical and functional indexes in patient with and without ID depending on the gender.Material and methods    An additional analysis of the study "Prevalence of Iron Deficiency in Patients With Chronic Heart Failure in the Russian Federation (ID-CHF-RF)" was performed. The study included 498 (198 women, 300 men) patients with CHF, in whom, in addition to iron metabolism, the quality of life and exercise tolerance (ET) were studied. 97 % of patients were enrolled during their stay in a hospital. ID was defined in consistency with the European Society of Cardiology (ESC) Guidelines. Also, and additional analysis was performed according to ID criteria validated by the morphological picture of the bone marrow.Results    ID was detected in 174 (87.9 %) women and 239 (79.8 %) men (p=0.028) according to the ESC criteria, and in 154 (77.8 %) women and 217 (72.3 %) men (p=0.208) according to the criteria validated by the morphological picture of the bone marrow. Men with ID were older and had more severe CHF. They more frequently had HF functional class (FC) III and IV (63.4 % vs. 43.3 % in men without ID); higher concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP) and lower ET. HF FC III increased the probability of ID presence 3.4 times (p=0.02) and the probability of HF FC IV 13.7 times (p=0.003). This clinical picture was characteristic of men when either method of determining ID was used. In women, ID was not associated with more severe CHF.Conclusion    Based on the presented analysis, it is possible to characterize the male and female ID phenotypes. The male ID phenotype is associated with more severe CHF, low ET, and poor quality of life. In females of the study cohort, ID was not associated with either the severity of CHF or with ET.

Relationship of Iron Deficiency, Anemia and Combination of Iron Deficiency With Anemia With Severity of Manifestations of Chronic Heart Failure. Additional Analysis of the Study "Prevalence of Iron Deficiency in Patients With Chronic Heart Failure in the Russian Federation (J-CHF-RF)"

Aim      To evaluate the role of iron deficiency (ID) identified by various criteria, anemia, and the combination of ID and anemia in determining the severity of the clinical course of chronic heart failure (CHF) in a retrospective analysis of data from 498 patients who participated in the ID-CHF-RF Russian multicenter program.Material and methods  ID was diagnosed by the following three criteria established by the European Society of Cardiology (ESC) and the Russian Society of Cardiology (RSC): 1) ferritin concentration <100 μg/l or ferritin concentration 100-299 μg/l in combination with a decreased transferrin saturation (TS) <20%; 2) ID criteria that showed a high sensitivity and specificity when compared with bone marrow morphology (BMM): TS ≤19.8% or serum iron (SI) ≤13 μmol/l; and 3) a composite index including a ferritin concentration <100 μg/l in combination with TS <20% and SI ≤13 μmol/l. The presence of anemia was defined as a hemoglobin concentration of less than 12.0 g/dl in women and less than 13.0 g/dl in men according to the criteria of the World Health Organization.Results Concomitant anemia was detected in 40.3% of patients with CHF; in 85.1% of cases, anemia was combined with the SI concentration below normal. CHF patients with concomitant anemia were significantly older and had low levels of not only red blood cells and hemoglobin but also all parameters of iron metabolism, i.e., SI, ferritin concentration, and TS. The mean deviation of the red blood cell size, that characterizes the degree of anisocytosis, was significantly increased in patients with anemia, especially with a low SI. These patients had a higher CHF functional class, elevated levels of N-terminal fragment of pro-brain natriuretic peptide (NT-proBNP) and walked a shorter distance in the 6-minute walk test, which reflects significantly more severe manifestations of CHF with concomitant anemia, particularly in combination with a low SI. The incidence of ID was 83.1% (including 23.3% in combination with anemia) according to the ESC/RSC criteria; 74.5% (including 43.3% with anemia) according to the BMM criteria; and 51.6% (including 51.7% with anemia) according to the composite index, which seems to be stricter compared to the first two criteria. Regardless of the assessment method (by total weighted average data), in ID combined with anemia, not only the hemoglobin concentration was significantly reduced but all three analyzed parameters of iron metabolism were also significantly reduced (SI 9.0 μmol/l vs. 10.4 μmol/l; ferritin 41 μg/l vs. 59 μg/l; TS 8.5% vs. 12.9%) compared to ID without anemia, respectively. The CHF severity and the NT-proBNP concentration were also maximum for the combination of ID and anemia, in contrast to ID without anemia, regardless of the ID criterion used. A more accurate comparison of the methods for determining ID in CHF in the context of their prognostic value will be obtained by analyzing the data of a two-year follow-up of patients in this study, which will be the subject of the next article.Conclusion      This analysis suggests that the presence of concomitant ID without anemia or anemia without ID moderately affects the severity of clinical manifestations of CHF and may be rather markers than factors determining the course of the disease, and in this case, does not require special correction with iron medications. And only ID anemia (a combination of ID with anemia) in patients with CHF can be considered a condition requiring special correction (for example, with intravenous medication) in addition to optimal therapy for CHF. This conclusion does not change depending on the used criteria for ID and requires verification in new RCTs.