Multiparametric Evaluation of Post-MI Small Animal Models Using Metabolic ([18F]FDG) and Perfusion-Based (SYN1) Heart Viability Tracers

Cardiovascular diseases (CVD), with myocardial infarction (MI) being one of the crucial components, wreak havoc in developed countries. Advanced imaging technologies are required to obtain quick and widely available diagnostic data. This paper describes a multimodal approach to in vivo perfusion imaging using the novel SYN1 tracer based on the fluorine-18 isotope. The NOD-SCID mice were injected intravenously with SYN1 or [18F] fluorodeoxyglucose ([18F]-FDG) radiotracers after induction of the MI. In all studies, the positron emission tomography–computed tomography (PET/CT) technique was used. To obtain hemodynamic data, mice were subjected to magnetic resonance imaging (MRI). Finally, the biodistribution of the SYN1 compound was performed using Wistar rat model. SYN1 showed normal accumulation in mouse and rat hearts, and MI hearts correctly indicated impaired cardiac segments when compared to [18F]-FDG uptake. In vivo PET/CT and MRI studies showed statistical convergence in terms of the size of the necrotic zone and cardiac function. This was further supported with RNAseq molecular analyses to correlate the candidate function genes’ expression, with Serpinb1c, Tnc and Nupr1, with Trem2 and Aldolase B functional correlations showing statistical significance in both SYN1 and [18F]-FDG. Our manuscript presents a new fluorine-18-based perfusion radiotracer for PET/CT imaging that may have importance in clinical applications. Future research should focus on confirmation of the data elucidated here to prepare SYN1 for first-in-human trials.

Transferrin Isoforms, Old but New Biomarkers in Hereditary Fructose Intolerance

Hereditary Fructose Intolerance (HFI) is an autosomal recessive inborn error of metabolism characterised by the deficiency of the hepatic enzyme aldolase B. Its treatment consists in adopting a fructose-, sucrose-, and sorbitol (FSS)-restrictive diet for life. Untreated HFI patients present an abnormal transferrin (Tf) glycosylation pattern due to the inhibition of mannose-6-phosphate isomerase by fructose-1-phosphate. Hence, elevated serum carbohydrate-deficient Tf (CDT) may allow the prompt detection of HFI. The CDT values improve when an FSS-restrictive diet is followed; however, previous data on CDT and fructose intake correlation are inconsistent. Therefore, we examined the complete serum sialoTf profile and correlated it with FSS dietary intake and with hepatic parameters in a cohort of paediatric and adult fructosemic patients. To do so, the profiles of serum sialoTf from genetically diagnosed HFI patients on an FSS-restricted diet (n = 37) and their age-, sex- and body mass index-paired controls (n = 32) were analysed by capillary zone electrophoresis. We found that in HFI patients, asialoTf correlated with dietary intake of sucrose (R = 0.575, p < 0.001) and FSS (R = 0.475, p = 0.008), and that pentasialoTf+hexasialoTf negatively correlated with dietary intake of fructose (R = −0.386, p = 0.024) and FSS (R = −0.400, p = 0.019). In addition, the tetrasialoTf/disialoTf ratio truthfully differentiated treated HFI patients from healthy controls, with an area under the ROC curve (AUROC) of 0.97, 92% sensitivity, 94% specificity and 93% accuracy.

Molecular and clinical findings of Turkish patients with hereditary fructose intolerance

Objectives Hereditary fructose intolerance (HFI) is an autosomal recessive disorder caused by a deficiency in aldolase B that can result in hypoglycemia, nausea, vomiting, abdominal pain, liver and kidney dysfunction, coma, and even death. This study aims to represent the clinical features and molecular genetic analysis data of the patients diagnosed with HFI in our study population. Methods The medical records of the 26 patients with HFI were evaluated retrospectively. Age, gender, clinical findings, metabolic crises, and the results of molecular analyses were recorded. Results The patients with HFI had a good prognosis and the aversion to sugar-containing foods was the main complaint. Seven different variants were identified in the Aldolase B (ALDOB) gene in HFI patients. The most frequent mutations were p.Ala150Pro, p.Ala175Asp had a prevalence of 61 and 30%, respectively, in agreement with the literature and other known variants were found with minor frequencies c.360-363del4(3.8%), p.Asn335Lys(3.8%), and three novel mutations c.113-1_15del4 (3.8%), p.Ala338Val(7.6%), and p.Asp156His(3.8%) were identified at a heterozygous, homozygous, or compound heterozygous level. Conclusions This study results revealed three novel mutations in patients with HFI. On the basis of age of presentation, clinical symptoms, and metabolic crisis, there was no clear-cut genotype-phenotype correlation. This article also demonstrates the importance of screening suspected infants in cases of acute liver failure for prompt diagnosis and treatment of HFI.

ALDOB Promotes Neuroblastoma Metastasis by Affecting EMT Pathway and is a Potential Prognostic Factor

Background： Aldolase B (ALDOB) is a member of the aldolase family, which is the fourth enzyme in glycolysis process. In recent years, the non-enzymatic effects of some glycolytic enzymes have been reported to promote the formation of several human tumors, but the non-enzymatic action of ALDOB in neuroblastoma(NB) remains unclear. This study aims to explore the non-enzymatic effect of ALDOB in neuroblastoma.Methods： We used immunohistochemistry to examine 63 patients tissue microarray samples and 3 pairs of lymph node metastases and the primary tissue samples, and evaluated the relationship between ALDOB expression level and clinical characteristics. We then analyzed the public datasets of NB based on microarray to verify the immunohistochemistry results. In addition, we conducted in vitro experiments on SK-N-BE(2) and SH-SY5Y cell lines to explore the molecular mechanism.Results： Immunohistochemistry indicated ALDOB is significantly associated with INSS stage and tumor metastasis in NB, public dataset analysis showed ALDOB is related to NB patient survival remarkably. In vitro experiments displayed silencing ALDOB may inhibit the cell migration by epithelial-mesenchymal transition (EMT) pathway.Conclusions： Our finding demonstrated that ALDOB can affect the metastasis of NB by EMT pathway and may be a potential target for neuroblastoma therapy in the future.

Loss of hepatic aldolase B activates Akt and promotes hepatocellular carcinogenesis by destabilizing the Aldob/Akt/PP2A protein complex

Loss of hepatic fructose-1, 6-bisphosphate aldolase B (Aldob) leads to a paradoxical up-regulation of glucose metabolism to favor hepatocellular carcinogenesis (HCC), but the upstream signaling events remain poorly defined. Akt is highly activated in HCC, and targeting Akt is being explored as a potential therapy for HCC. Herein, we demonstrate that Aldob suppresses Akt activity and tumor growth through a protein complex containing Aldob, Akt, and protein phosphatase 2A (PP2A), leading to inhibition of cell viability, cell cycle progression, glucose uptake, and metabolism. Interestingly, Aldob directly interacts with phosphorylated Akt (p-Akt) and promotes the recruitment of PP2A to dephosphorylate p-Akt, and this scaffolding effect of Aldob is independent of its enzymatic activity. Loss of Aldob or disruption of Aldob/Akt interaction in Aldob R304A mutant restores Akt activity and tumor-promoting effects. Consistently, Aldob and p-Akt expression are inversely correlated in human HCC tissues, and Aldob down-regulation coupled with p-Akt up-regulation predicts a poor prognosis for HCC. We have further discovered that Akt inhibition or a specific small-molecule activator of PP2A (SMAP) efficiently attenuates HCC tumorigenesis in xenograft mouse models. Our work reveals a novel nonenzymatic role of Aldob in negative regulation of Akt activation, suggesting that directly inhibiting Akt activity or through reactivating PP2A may be a potential therapeutic approach for HCC treatment.

Aldolase B is differentially expressed in brain metastatic breast cancer.

Brain metastases affect up to 34% of breast cancer patients treated with trastuzumab (1). Limited treatment options are available for clinical control of brain metastatic breast cancer (2-4). We mined published microarray data (5, 6) to identify genes associated with metastasis to the brain in human breast cancer. This unbiased, global gene expression analysis identified differential expression of aldolase B, encoded by the gene Aldob, an enzyme functioning in the metabolism of fructose (7, 8), as a transcriptional feature of brain metastasis in patients with breast cancer. Aldolase B may be of relevance to processes underlying metastasis to the brain in human metastatic breast cancer.

Hexokinase 2 (HK2) is over-expressed in brain metastatic breast cancer.

Brain metastases are a clinical problem in patients with breast cancer (1-3). We mined published microarray data (4, 5) to discover genes associated with brain metastasis in patients with brain metastatic breast cancer. We found that the gene encoding hexokinase 2, HK2, a metabolic enzyme converting glucose to glucose-6-phosphate, among the genes most differentially expressed in the brain metastases of patients with brain metastatic breast cancer. We recently reported that aldolase B is differentially expressed in metastatic brain tissues in human breast cancer (6). Thus, genes involved in both fructose and glucose metabolism are among those most significantly perturbed at the transcriptional level in the brain metastases of humans with metastatic breast cancer.

Chronic exposure to IL6 leads to deregulation of glycolysis and fat accumulation in the zebrafish liver

BACKGROUND AND AIMSInflammation is a constant in Non-Alcoholic Fatty Liver Disease (NAFLD) and is usually considered a consequence. We propose that inflammation can be a cause for NAFLD. Obesity is strongly associated with (NAFLD), but not always. NAFLD in lean individuals is more common in certain populations, especially Asian-Indians. Lean healthy Indians also have a higher basal circulating IL6 suggesting a link with inflammation. We propose that inflammation-induced fatty liver could be relevant for studying obesity-independent NAFLD. Commonly used high-fat diet-induced NAFLD animal models are not ideal for testing this hypothesis.APPROACH AND RESULTSIn this study we used a transgenic zebrafish with chronic systemic overexpression of human IL6 (IL6-OE) and found accumulation of triglyceride in the liver. We performed comparative transcriptomics and proteomics on the IL6-OE liver and found an expression signature distinct from the diet-based NAFLD models. We discovered a deregulation of glycolysis/gluconeogenesis pathway, especially a robust down regulation of the glycolytic enzyme aldolase b in the IL6-OE liver. Metabolomics of the IL6-OE liver showed accumulation of hexose monophosphates and their derivatives, which can act as precursors for triglyceride synthesis. Patients with the genetic disease Hereditary Fructose Intolerance (HFI) caused by ALDOLASE B deficiency also have a higher propensity to develop fatty liver disease.CONCLUSIONSOur study demonstrates a causative role for inflammation in intrahepatic lipid accumulation. Further, our results suggest that IL6-driven repression of glycolysis/gluconeogenesis, specifically aldolase b, may be a novel mechanism for development of fatty liver, especially in obesity-independent NAFLD.