Glucose transporters and sodium glucose co-transporters cooperatively import glucose into energy-demanding organs in carcinogenic liver fluke Clonorchis sinensis.

BACKGROUND: The liver fluke Clonorchis sinensis imports large amounts of glucose to generate energy and metabolic intermediates through glycolysis. We hypothesized that C. sinensis absorbs glucose through glucose transporters and identified four subtypes of glucose transporter (CsGTP) and one sodium glucose co-transporter (CsSGLT) in C. sinensis. METHODOLOGY/PRINCIPAL FINDINGS: Expressed sequence tags encoding CsGTPs were retrieved from the C. sinensis transcriptome database, and their full-length cDNA sequences were obtained by rapid amplification of cDNA ends (RACE). The tissue distribution of glucose transporters in C. sinensis adults was determined using immunohistochemical staining. Developmental expression was measured using RT-qPCR. The transport and distribution of glucose into living C. sinensis were monitored using confocal microscopy. Membrane topology and key functional residues of CsGTPs were homologous to their counterparts in animals and humans. CsGTP1, 2, and 4 were transcribed 2.4-5.5 times higher in the adults than metacercariae, while CsGTP3 was transcribed 2.1 times higher in the metacercariae than adults. CsSGLT transcription was 163.6 times higher in adults than in metacercariae. In adults, CsSGLT was most abundant in the tegument; CsGTP3 and CsSGLT were localized in the vitelline gland, uterine wall, eggs, mesenchymal tissue, and testes; CsGTP4 was found in sperm and mesenchymal tissue; and CsGTP1 was mainly in the sperm and testes. In C. sinensis adults, exogenous glucose is imported in a short time and is present mainly in the middle and posterior body, in which the somatic and reproductive organs are located. Of the exogenous glucose, 53.6% was imported through CsSGLT and 46.4% through CsGTPs. Exogenous glucose import was effectively inhibited by cytochalasin B and phlorizin. CONCLUSIONS/SIGNIFICANCE: We propose that CsSGLT cooperates with CsGTPs to import exogenous glucose from the environmental bile, transport glucose across mesenchymal tissue cells, and finally supply energy-demanding organs in C. sinensis adults. Studies on glucose transporters may pave the way for the development of new anthelmintic drugs.

Genetic imputation of kidney transcriptome, proteome and multi-omics illuminates new blood pressure and hypertension targets.

Genetic mechanisms of blood pressure (BP) regulation remain poorly defined. Using kidney-specific epigenomic annotations and 3D genome information we generated and validated gene expression prediction models for the purpose of transcriptome-wide association studies in 700 human kidneys. We identified 889 kidney genes associated with BP of which 399 were prioritised as contributors to BP regulation. Imputation of kidney proteome and microRNAome uncovered 97 renal proteins and 11 miRNAs associated with BP. Integration with plasma proteomics and metabolomics illuminated circulating levels of myo-inositol, 4-guanidinobutanoate and angiotensinogen as downstream effectors of several kidney BP genes (SLC5A11, AGMAT, AGT, respectively). We showed that genetically determined reduction in renal expression may mimic the effects of rare loss-of-function variants on kidney mRNA/protein and lead to an increase in BP (e.g., ENPEP). We demonstrated a strong correlation (r = 0.81) in expression of protein-coding genes between cells harvested from urine and the kidney highlighting a diagnostic potential of urinary cell transcriptomics. We uncovered adenylyl cyclase activators as a repurposing opportunity for hypertension and illustrated examples of BP-elevating effects of anticancer drugs (e.g. tubulin polymerisation inhibitors). Collectively, our studies provide new biological insights into genetic regulation of BP with potential to drive clinical translation in hypertension.

Knocking Out Sodium Glucose-Linked Transporter 5 Prevents Fructose-Induced Renal Oxidative Stress and Salt-Sensitive Hypertension.

BACKGROUND: A fructose high-salt (FHS) diet increases systolic blood pressure and Ang II (angiotensin II)-stimulated proximal tubule (PT) superoxide (O2-) production. These increases are prevented by scavenging O2- or an Ang II type 1 receptor antagonist. SGLT4 (sodium glucose-linked cotransporters 4) and SGLT5 are implicated in PT fructose reabsorption, but their roles in fructose-induced hypertension are unclear. We hypothesized that PT fructose reabsorption by SGLT5 initiates a genetic program enhancing Ang II-stimulated oxidative stress in males and females, thereby causing fructose-induced salt-sensitive hypertension. METHODS: We measured systolic blood pressure in male and female Sprague-Dawley (wild type [WT]), SGLT4 knockout (-/-), and SGLT5-/- rats. Then, we measured basal and Ang II-stimulated (37 nmol/L) O2- production by PTs and conducted gene coexpression network analysis. RESULTS: In male WT and female WT rats, FHS increased systolic blood pressure by 15±3 (n=7; P<0.0027) and 17±4 mm Hg (n=9; P<0.0037), respectively. Male and female SGLT4-/- had similar increases. Systolic blood pressure was unchanged by FHS in male and female SGLT5-/-. In male WT and female WT fed FHS, Ang II stimulated O2- production by 14±5 (n=6; P<0.0493) and 8±3 relative light units/µg protein/s (n=7; P<0.0218), respectively. The responses of SGTL4-/- were similar. Ang II did not stimulate O2- production in tubules from SGLT5-/-. Five gene coexpression modules were correlated with FHS. These correlations were completely blunted in SGLT5-/- and partially blunted by chronically scavenging O2- with tempol. CONCLUSIONS: SGLT5-mediated PT fructose reabsorption is required for FHS to augment Ang II-stimulated proximal nephron O2- production, and increases in PT oxidative stress likely contribute to FHS-induced hypertension.

The role of the mitochondrial ribosomal protein family in detecting hepatocellular carcinoma and predicting prognosis, immune features, and drug sensitivity

Background Hepatocellular carcinoma (HCC) is one of the most common types of malignant tumors, with a slow onset, rapid progression, and frequent recurrence. Previous research has implicated mitochondrial ribosomal genes in the development, metastasis, and prognosis of various cancers. However, further research is necessary to establish a link between mitochondrial ribosomal protein (MRP) family expression and HCC diagnosis, prognosis, ferroptosis-related gene (FRG) expression, m6A modification-related gene expression, tumor immunity, and drug sensitivity. Methods Bioinformatics resources were used to analyze data from patients with HCC retrieved from the TCGA, ICGC, and GTEx databases (GEPIA, UALCAN, Xiantao tool, cBioPortal, STRING, Cytoscape, TISIDB, and GSCALite). Results Among the 82 MRP family members, 14 MRP genes (MRPS21, MRPS23, MRPL9, DAP3, MRPL13, MRPL17, MRPL24, MRPL55, MRPL16, MRPL14, MRPS17, MRPL47, MRPL21, and MRPL15) were significantly upregulated differentially expressed genes (DEGs) in HCC tumor samples in comparison to normal samples. Receiver-operating characteristic curve analysis indicated that all 14 DEGs show good diagnostic performance. Furthermore, TCGA analysis revealed that the mRNA expression of 39 MRPs was associated with overall survival (OS) in HCC. HCC was divided into two molecular subtypes (C1 and C2) with distinct prognoses using clustering analysis. The clusters showed different FRG expression and m6A methylation profiles and immune features, and prognostic models showed that the model integrating 5 MRP genes (MRPS15, MRPL3, MRPL9, MRPL36, and MRPL37) and 2 FRGs (SLC1A5 and SLC5A11) attained a greater clinical net benefit than three other prognostic models. Finally, analysis of the CTRP and GDSC databases revealed several potential drugs that could target prognostic MRP genes (AU)

Dapagliflozin and Mode of Death in Heart Failure With Improved Ejection Fraction: A Post Hoc Analysis of the DELIVER Trial.

Importance: Heart failure with improved ejection fraction (HFimpEF), defined as prior left ventricular ejection fraction (LVEF) 40% or lower that has increased to greater than 40%, is understudied. Objective: To examine mode of death and the association of dapagliflozin with reductions in cause-specific death in patients with HFimpEF. Design, Setting, and Participants: This was a post hoc analysis from the Dapagliflozin Evaluation to Improve the Lives of Patients With Preserved Ejection Fraction Heart Failure (DELIVER) randomized clinical trial, conducted from August 2018 to December 2020. The trial randomly assigned patients with HF with LVEF greater than 40%, New York Heart Association class II to IV symptoms, and elevated natriuretic peptides to treatment with dapagliflozin (10 mg, once daily) or placebo. The presence of HFimpEF was captured through study case report forms. The primary outcome was a composite of worsening HF events (hospitalization or urgent HF visits) or cardiovascular death. Clinical outcomes were adjudicated by a blinded clinical end points committee. Data were analyzed from May 2022 to August 2023. Intervention: Dapagliflozin vs placebo. Main Outcomes and Measures: The mode of death in relation to HFimpEF status was examined, as well as the association of randomized treatment with cause-specific death in Cox regression models. Results: Of 1151 patients with HFimpEF in DELIVER, 190 (16.5%) died, compared with 833 patients (16.3%) of 5112 with LVEF consistently greater than 40%. The overall distribution of mode of death was similar in those with HFimpEF compared with those with LVEF consistently greater than 40% (noncardiovascular death: 103 of 190 [54%] vs 428 of 833 [51%]; cardiovascular death: 87 of 190 [46%] vs 405 of 833 [49%], respectively). Most deaths in individuals with HFimpEF were noncardiovascular (103 of 180 [54%]). For cardiovascular deaths, sudden deaths were most common (36 of 190 events [19%]), followed by HF-related (29 of 190 events [15%]). Among patients with HFimpEF, treatment with dapagliflozin was associated with lower rates of cardiovascular death relative to placebo, a difference primarily due to lower rates of sudden death (hazard ratio, 0.38; 95% CI, 0.18-0.79; P for interaction = .01). Conclusions and Relevance: The findings in this study support current guideline recommendations for use of sodium-glucose transport protein 2 inhibitor therapy, and further suggest that the addition of a sodium-glucose transport protein 2 inhibitor therapy to other guideline-directed medical therapies may help reduce cardiovascular mortality in patients with HFimpEF. Trial Registration: ClinicalTrials.gov Identifier: NCT03619213.

The role of the mitochondrial ribosomal protein family in detecting hepatocellular carcinoma and predicting prognosis, immune features, and drug sensitivity.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common types of malignant tumors, with a slow onset, rapid progression, and frequent recurrence. Previous research has implicated mitochondrial ribosomal genes in the development, metastasis, and prognosis of various cancers. However, further research is necessary to establish a link between mitochondrial ribosomal protein (MRP) family expression and HCC diagnosis, prognosis, ferroptosis-related gene (FRG) expression, m6A modification-related gene expression, tumor immunity, and drug sensitivity. METHODS: Bioinformatics resources were used to analyze data from patients with HCC retrieved from the TCGA, ICGC, and GTEx databases (GEPIA, UALCAN, Xiantao tool, cBioPortal, STRING, Cytoscape, TISIDB, and GSCALite). RESULTS: Among the 82 MRP family members, 14 MRP genes (MRPS21, MRPS23, MRPL9, DAP3, MRPL13, MRPL17, MRPL24, MRPL55, MRPL16, MRPL14, MRPS17, MRPL47, MRPL21, and MRPL15) were significantly upregulated differentially expressed genes (DEGs) in HCC tumor samples in comparison to normal samples. Receiver-operating characteristic curve analysis indicated that all 14 DEGs show good diagnostic performance. Furthermore, TCGA analysis revealed that the mRNA expression of 39 MRPs was associated with overall survival (OS) in HCC. HCC was divided into two molecular subtypes (C1 and C2) with distinct prognoses using clustering analysis. The clusters showed different FRG expression and m6A methylation profiles and immune features, and prognostic models showed that the model integrating 5 MRP genes (MRPS15, MRPL3, MRPL9, MRPL36, and MRPL37) and 2 FRGs (SLC1A5 and SLC5A11) attained a greater clinical net benefit than three other prognostic models. Finally, analysis of the CTRP and GDSC databases revealed several potential drugs that could target prognostic MRP genes. CONCLUSION: We identified 14 MRP genes as HCC diagnostic markers. We investigated FRG and m6A modification-related gene expression profiles and immune features in patients with HCC, and developed and validated a model incorporating MRP and FRG expression that accurately and reliably predicts HCC prognosis and may predict disease progression and treatment response.

Masked anemia and hematocrit elevation under sodium glucose transporter inhibitors: findings from a large real-world study.

AIMS: Sodium glucose transporter inhibitors (SGLT2i) therapy is associated with an increase in hematocrit as a class effect. There is a lack of information regarding the clinical magnitude and significance of hematocrit elevation, especially cardiovascular outcomes in patients with polycythemia and possible masking of lower hemoglobin levels as a sign of potential severe disease. METHODS: A retrospective study utilizing large community healthcare provider electronic database. Hematocrit levels and variables with potential effect on hematocrit change were compared before and during SGLT2i treatment in adults with type 2 diabetes mellitus. RESULTS: Study population included 9646 patients treated with Dapagliflozin or Empagliflozin between 01.2015 and 06.2019. Hematocrit levels were significantly higher after treatment initiation (2.1%), with higher median elevation among male vs female (2.3% vs. 1.8%). Anemia prevalence was significantly lower under treatment (20% vs. 31.6%). In multivariable model, gender, smoking status, SGLT2i type, pretreatment hematocrit, diabetes duration, body mass index and estimated glomerular filtration rate change significantly effected hematocrit change. CONCLUSIONS: In the current study SGLT2i treatment was associated with significant hematocrit elevation, polycythemia and lower anemia prevalence. Further studies are needed to determine the clinical significance and approach to patients with pretreatment or on treatment polycythemia and the approach to patients with lower-normal hemoglobin levels under SGLT2i treatment.

Membrane potential accelerates sugar uptake by stabilizing the outward facing conformation of the Na/glucose symporter vSGLT.

Sodium-dependent glucose transporters (SGLTs) couple a downhill Na+ ion gradient to actively transport sugars. Here, we investigate the impact of the membrane potential on vSGLT structure and function using sugar uptake assays, double electron-electron resonance (DEER), electrostatic calculations, and kinetic modeling. Negative membrane potentials, as present in all cell types, shift the conformational equilibrium of vSGLT towards an outward-facing conformation, leading to increased sugar transport rates. Electrostatic calculations identify gating charge residues responsible for this conformational shift that when mutated reduce galactose transport and eliminate the response of vSGLT to potential. Based on these findings, we propose a comprehensive framework for sugar transport via vSGLT, where the cellular membrane potential facilitates resetting of the transporter after cargo release. This framework holds significance not only for SGLTs but also for other transporters and channels.

Sodium Glucose Transporter-2 Inhibitors (SGLT2Is)-TLRs Axis Modulates Diabetes.

Diabetes affects millions of people worldwide and is mainly associated with impaired insulin function. To date, various oral anti-diabetic drugs have been developed, of which, the sodium glucose transporter-2 inhibitors (SGLT2Is) are of the most recent classes that have been introduced. They differ from other classes in terms of their novel mechanism of actions and unique beneficial effects rather than just lowering glucose levels. SGLT2Is can protect body against cardiovascular events and kidney diseases even in non-diabetic individuals. SGLT2Is participate in immune cell activation, oxidative stress reduction, and inflammation mediation, thereby, moderating diabetic complications. In addition, toll like receptors (TLRs) are the intermediators of the immune system and inflammatory process, thus it's believed to play crucial roles in diabetic complications, particularly the ones that are related to inflammatory reactions. SGLT2Is are also effective against diabetic complications via their anti-inflammatory and oxidative properties. Given the anti-inflammatory properties of TLRs and SGLT2Is, this review investigates how SGLT2Is can affect the TLR pathway, and whether this could be favorable toward diabetes.

Review: A species comparison of the kinetic homogeneous and heterogeneous organization of sodium-dependent glucose transport systems along the intestine.

The targeted use of carbohydrates by feed and food industries to create balanced and cost-effective diets has generated a tremendous amount of research in carbohydrate digestion and absorption in different species. Specifically, this research has led us to a larger observation that identified different organizations of intestinal sodium-dependent glucose absorption across species, which has not been previously collated and reviewed. Thus, this review will compare the kinetic segregation of sodium-dependent glucose transport across the intestine of different species, which we have termed either homogeneous or heterogeneous systems. For instance, the pig follows a heterogeneous system of sodium-dependent glucose transport with a high-affinity, super-low-capacity (Ha/sLc) in the jejunum, and a high-affinity, super-high-capacity (Ha/sHc) in the ileum. This is achieved by multiple sodium-dependent glucose transporters contributing to each segment. In contrast, tilapia have a homogenous system characterized by high-affinity, high-capacity (Ha/Hc) throughout the intestine. Additionally, we are the first to report glucose transporter patterns across species presented from vertebrates to invertebrates. Finally, other kinetic transport systems are briefly covered to illustrate possible contributions/modulations to sodium-dependent glucose transporter organization. Overall, we present a new perspective on the organization of glucose absorption along the intestinal tract.

Collective Domain Motion Facilitates Water Transport in SGLT1.

The human sodium-glucose cotransporter protein (SGLT1) is an important representative of the sodium solute symporters belonging to the secondary active transporters that are critical to the homeostasis of sugar, sodium, and water in the cell. The underlying transport mechanism of SGLT1 is based on switching between inward- and outward-facing conformations, known as the alternating access model, which is crucial for substrate transport, and has also been postulated for water permeation. However, the nature of water transport remains unclear and is disputed along the passive and active transport, with the latter postulating the presence of the pumping effect. To better examine the water transport in SGLT1, we performed a series of equilibrium all-atom molecular dynamics simulations, totaling over 6 µs of sample representative conformational states of SGLT1 and its complexes, with the natural substrates, ions, and inhibitors. In addition to elucidating the basic physical factors influencing water permeation, such as channel openings and energetics, we focus on dynamic flexibility and its relationship with domain motion. Our results clearly demonstrate a dependence of instantaneous water flux on the channel opening and local water diffusion in the channel, strongly supporting the existence of a passive water transport in SGLT1. In addition, a strong correlation found between the local water diffusion and protein domain motion, resembling the "rocking-bundle" motion, reveals its facilitating role in the water transport.

Sodium-Glucose Co-Transporters Family: Current Evidence, Clinical Applications and Perspectives.

Sodium-glucose co-transporters (SGLTs) family members are involved in several vital biological functions. Except for SGLT3, they are involved in the mechanisms of active transport of sodium and glucose and several micromolecules. The discovery of functions and mechanisms of SGLT1 inhibition and, in particular, of SGLT2 has radically changed the natural history of some pathologies. SGLT2 inhibitors have revolutionized the therapeutic approach not only of type 2 diabetes mellitus but also of heart failure and chronic kidney failure. Considering the role played by the other SGLTs and the functions still unknown to date, clinical implications of the inhibition of SGLT2 could represent the prelude for a wider modulation of these cotransporters. A better understanding of the role and function of SGLTs could represent a revolution in the therapeutic approach in the hepatological, metabolic, neurological and oncological fields. The purpose of this review is to illustrate the knowledge currently available on SGLTs, its clinical implications and future perspectives.

Precision medicine in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disease that has diverse clinical manifestations, ranging from restricted cutaneous involvement to life-threatening systemic organ involvement. The heterogeneity of pathomechanisms that lead to SLE contributes to between-patient variation in clinical phenotype and treatment response. Ongoing efforts to dissect cellular and molecular heterogeneity in SLE could facilitate the future development of stratified treatment recommendations and precision medicine, which is a considerable challenge for SLE. In particular, some genes involved in the clinical heterogeneity of SLE and some phenotype-related loci (STAT4, IRF5, PDGF genes, HAS2, ITGAM and SLC5A11) have an association with clinical features of the disease. An important part is also played by epigenetic varation (in DNA methylation, histone modifications and microRNAs) that influences gene expression and affects cell function without modifying the genome sequence. Immune profiling can help to identify an individual's specific response to a therapy and can potentially predict outcomes, using techniques such as flow cytometry, mass cytometry, transcriptomics, microarray analysis and single-cell RNA sequencing. Furthermore, the identification of novel serum and urinary biomarkers would enable the stratification of patients according to predictions of long-term outcomes and assessments of potential response to therapy.

Meta-Analysis on the Safety and Efficacy of Sodium Glucose Cotransporters 2 Inhibitors in Patients With Heart Failure With and Without Diabetes.

Heart failure (HF) is the most common cardiovascular cause of hospitalization in patients over 60 years, affecting about 64.3 million patients worldwide. Few studies have investigated the role of sodium glucose cotransporter inhibitors (SGLT2Is) in patients with HF without and without diabetes. Thus, we conducted our meta-analysis to further investigate the role of SGLT2I role in patients with HF without and without diabetes. PubMed, Scopus, Web of Science, and Embase were searched. All clinical trials that compared the effect of SGLT2Is versus placebo on patients with HF were included. Dichotomous data were extracted, pooled as risk ratio (RR) with 95% confidence interval (CI), and analyzed using RevMan version 5.3 for windows using the Mantel-Haenszel method. A total of 13 randomized clinical trials were included for analysis, with a total number of 75,287 patients. SGLT2Is significantly lowered the risk of hospitalization for HF in patients with (RR = 0.68, 95% CI 0.63 to 0.74) and without diabetes (RR = 0.75, 95% CI 0.62 to 0.89). Furthermore, they lowered the mortality risk in both patients with diabetes with statistical significance (RR = 0.87, 95% CI 0.77 to 0.99), yet without statistical significance in patients without diabetes (RR = 0.93, 95% CI 0.70 to 1.23). Further analyses for serious adverse events were conducted, and SGLT2I showed a significant lower risk in patients with diabetes (RR = 0.94, 95% CI 0.90 to 0.98) and without diabetes (RR = 0.72, 95% CI 0.38 to 1.39). in patients with diabetes, SGLT2Is significantly reduced cardiovascular mortality, HHF, and serious adverse events. However, in patients without, despite showing a significant reduction in HHF, SGLT2I reduced cardiovascular mortality or serious adverse events but without statistical significance.

Pre-admission use of sodium glucose transporter-2 inhibitor (SGLT-2i) may significantly improves Covid-19 outcomes in patients with diabetes: A systematic review, meta-analysis, and meta-regression.

AIMS: This study aims to examine the effectiveness of using sodium glucose transporter-2 inhibitor (SGLT-2i) before hospital admission on Covid-19 outcomes in diabetic patients. METHODS: A literature search was conducted using specific keywords until October 24th, 2022 on 4 databases: Medline, Scopus, Cochrane Library, and ClinicalTrials.gov. All articles regarding SGLT-2i in diabetic patients with Covid-19 were included in the study. Outcomes in this study were calculated using random-effect models to generate pooled odds ratio (OR) with 95% confidence intervals (CI). RESULTS: A total of 17 studies were included in the analysis. Our meta-analysis showed that pre-admission use of SGLT-2i was associated with reduced mortality (OR 0.69; 95 %CI: 0.56 - 0.87, p = 0.001, I2 = 91 %) and severity of Covid-19 (OR 0.88; 95 %CI: 0.80 - 0.97, p = 0.008, I2 = 13 %). This benefit of SGLT-2i on Covid-19 mortality was not significantly affected by patient's factors such as age (p = 0.2335), sex (p = 0.2742), hypertension (p = 0.2165), heart failure (p = 0.1616), HbA1c levels (p = 0.4924), metformin use (p = 0.6617), duration of diabetes (p = 0.7233), and BMI (p = 0.1797). CONCLUSIONS: This study suggests that SGLT-2i as glucose lowering treatment in patients with diabetes has a positive effect on Covid-19 outcomes, therefore can be considered as an antidiabetic drug of choice, especially during the Covid-19 pandemic. Short Title: SGLT-2i in diabetes and Covid-19. REGISTRATION DETAILS: CRD42022369784.

Narrative review investigating the nephroprotective mechanisms of sodium glucose cotransporter type 2 inhibitors in diabetic and nondiabetic patients with chronic kidney disease.

Background and aims: Outcome trials using sodium glucose cotransporter type 2 inhibitors have consistently shown their potential to preserve kidney function in diabetic and nondiabetic patients. Several mechanisms have been introduced which may explain the nephroprotective effect of sodium glucose cotransporter type 2 inhibitors beyond lowering blood glucose. This current narrative review has the objective to describe main underlying mechanisms causing a nephroprotective effect and to show similarities as well as differences between proposed mechanisms which can be observed in patients with diabetic and nondiabetic chronic kidney disease. Methods: We performed a narrative review of the literature on Pubmed and Embase. The research string comprised various combinations of items including "chronic kidney disease", "sodium glucose cotransporter 2 inhibitor" and "mechanisms". We searched for original research and review articles published until march, 2022. The databases were searched independently and the agreements by two authors were jointly obtained. Results: Sodium glucose cotransporter type 2 inhibitors show systemic, hemodynamic, and metabolic effects. Systemic effects include reduction of blood pressure without compensatory activation of the sympathetic nervous system. Hemodynamic effects include restoration of tubuloglomerular feedback which may improve pathologic hyperfiltration observed in most cases with chronic kidney disease. Current literature indicates that SGLT2i may not improve cortical oxygenation and may reduce medullar oxygenation. Conclusion: Sodium glucose cotransporter type 2 inhibitors cause nephroprotective effects by several mechanisms. However, several mediators which are involved in the underlying pathophysiology may be different between diabetic and nondiabetic patients.

SOdium-glucose CO-transporter inhibition in patients with newly detected Glucose Abnormalities and a recent Myocardial Infarction (SOCOGAMI).

AIMS/HYPOTHESIS: Established dysglycaemia (impaired glucose tolerance [IGT] or type 2 diabetes [T2DM]) is a risk factor for further cardiovascular events in patients with coronary artery disease. Sodium-glucose cotransporter 2 inhibitors reduce this risk. The aim of the present investigation was to test the hypothesis that empagliflozin exerts beneficial effects on myocardial function in patients with a recent acute coronary syndrome and newly detected dysglycaemia. METHODS: Forty-two patients (mean age 67.5 years, 81 % male) with recent myocardial infarction (n = 36) or unstable angina (n = 6) and newly detected IGT (n = 27) or T2DM (n = 15) were randomised to 25 mg of empagliflozin daily (n = 20) or placebo (n = 22) on top of ongoing therapy. They were investigated with oral glucose tolerance tests, stress-perfusion cardiac magnetic resonance imaging (CMR) and echocardiography at three occasions: before randomisation, after seven months on study drug and three months following cessation of such drug. Primary outcome was a change in left ventricular (LV) end-diastolic volume (LVEDV) and secondary outcomes were a change in a) systolic and diastolic LV function; b) coronary flow reserve; c) myocardial extracellular volume (ECV) in non-infarcted myocardium; d) aortic pulse wave velocity. RESULTS: Empagliflozin induced a significant decrease in fasting and post load glucose (p < 0.05) and body weight (p < 0.01). Empagliflozin did not influence LVEDV, LV systolic or mass indexes, coronary flow reserve, ECV or aortic pulse wave velocity. Echocardiographic indices of LV diastolic function (E/e' and mitral E/A ratio) were not influenced. No safety concerns were identified. CONCLUSIONS/INTERPRETATION: Empagliflozin had predicted effects on the dysglycaemia but did not influence variables expressing LV function, coronary flow reserve and ECV. An explanation may be that the LV function of the patients was within the normal range.

Los iSGLT2 en la insuficiencia cardiaca. ¿Sus beneficios pueden extenderse a todo el espectro de la fracción de eyección? / SGLT2i in heart failure: can their benefits be expanded across the entire spectrum of ejection fraction?

La publicación del estudio EMPEROR-Preserved y la extensión del beneficio cardiovascular de los inhibidores del cotransportador de sodio-glucosa tipo 2 (iSGLT2) a pacientes con insuficiencia cardiaca IC y fracción de eyección (FE)> 40% supone un importante hito en el tratamiento de la IC con FE conservada (IC-FEc). A raíz de estos resultados, en febrero de 2022 la Food and Drug Administration estadounidense aprobó el uso de la empagliflozina para el tratamiento de pacientes con IC independientemente de la FE. Sin embargo, un análisis más detallado del estudio EMPEROR-Preserved genera ciertas dudas en relación con la banda de FE más alta (> 60%). Este grupo de pacientes presenta una gran heterogeneidad y probablemente no se pueda considerar un único fenotipo para fines terapéuticos y de abordaje clínico. Además, la FE es un parámetro continuo. Por ello, no parece que una diferenciación basada en puntos de corte matemáticos concuerde con la evidencia más reciente, que apunta precisamente a un cambio más gradual en cuanto a mecanismos subyacentes, etiologías y respuesta al tratamiento a lo largo del espectro de la FE. Un mejor conocimiento de los mecanismos fisiopatológicos es fundamental para establecer nuevas dianas terapéuticas, interpretar los resultados de los ensayos clínicos y desarrollar tratamientos dirigidos y eficaces (AU)

The publication of the EMPEROR-Preserved trial and data on the benefits of sodium-glucose cotransporter 2 (SGLT2) inhibitors in patients with heart failure (HF) with ejection fraction (EF)> 40% represent a significant step forward in the treatment of HF with preserved EF. Given these results, in February 2022 the US Food and Drug Administration approved the use of empaglifozin in adults with HF with reduced or preserved EF. However, more detailed analysis of the EMPEROR-Preserved trial led to doubts about the effect of empagliflozin in patients with an EF of> 60% this patient group is widely heterogeneous and, probably, a single phenotype cannot be considered in treatment goals or the clinical approach. Moreover, EF occurs on a continuum and classifications of HF according to arbitrary cut-points in EF do not appear consistent with recent evidence, which points to a gradual shift and considerable overlap in underlying mechanisms, phenotypes and treatment response over the spectrum of EF. Enhanced knowledge of pathophysiological mechanisms is essential to establish new therapeutic targets, interpret the results of clinical trials, and develop targeted and effective therapies (AU)

In Vivo Functional Assessment of Sodium-Glucose Cotransporters (SGLTs) Using [18F]Me4FDG PET in Rats.

Background: Mediating glucose absorption in the small intestine and renal clearance, sodium glucose cotransporters (SGLTs) have emerged as an attractive therapeutic target in diabetic patients. A substantial fraction of patients, however, only achieve inadequate glycemic control. Thus, we aimed to assess the potential of the SGLT-targeting PET radiotracer alpha-methyl-4-deoxy-4-[18F]fluoro-D-glucopyranoside ([18F]Me4FDG) as a noninvasive intestinal and renal biomarker of SGLT-mediated glucose transport. Methods: We investigated healthy rats using a dedicated small animal PET system. Dynamic imaging was conducted after administration of the reference radiotracer 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG), or the SGLT-targeting agent, [18F]Me4FDG either directly into the digestive tract (for assessing intestinal absorption) or via the tail vein (for evaluating kidney excretion). To confirm the specificity of [18F]Me4FDG and responsiveness to treatment, a subset of animals was also pretreated with the SGLT inhibitor phlorizin. In this regard, an intraintestinal route of administration was used to assess tracer absorption in the digestive tract, while for renal assessment, phlorizin was injected intravenously (IV). Results: Serving as reference, intestinal administration of [18F]FDG led to slow absorption with retention of 89.2 ± 3.5% of administered radioactivity at 15 min. [18F]Me4FDG, however, was rapidly absorbed into the blood and cleared from the intestine within 15 min, leading to markedly lower tracer retention of 18.5 ± 1.2% (P < 0.0001). Intraintestinal phlorizin led to marked increase of [18F]Me4FDG uptake (15 min, 99.9 ± 4.7%; P < 0.0001 vs. untreated controls), supporting the notion that this PET agent can measure adequate SGLT inhibition in the digestive tract. In the kidneys, radiotracer was also sensitive to SGLT inhibition. After IV injection, [18F]Me4FDG reabsorption in the renal cortex was significantly suppressed by phlorizin when compared to untreated animals (%ID/g at 60 min, 0.42 ± 0.10 vs. untreated controls, 1.20 ± 0.03; P < 0.0001). Conclusion: As a noninvasive read-out of the concurrent SGLT expression in both the digestive tract and the renal cortex, [18F]Me4FDG PET may serve as a surrogate marker for treatment response to SGLT inhibition. As such, [18F]Me4FDG may enable improvement in glycemic control in diabetes by PET-based monitoring strategies.