Aldolase B Research Articles

Loss of glomerular aldolase B in diabetic nephropathy promotes renal fibrosis via activating Akt/GSK/β-catenin axis.

Diabetic nephropathy (DN), characterized by a complex and multifaceted pathogenesis, stands as the foremost catalyst behind end-stage renal disease (ESRD). This study aims to analyze the level and non-metabolic role of glomerular aldolase B (ALDOB) in DN progression. Glomerular proteomics and transcriptome are analyzed from 50 DN patients and 25 controls, respectively. Human kidney biopsy, cultured podocytes and mouse models are employed to study ALDOB levels and function. ALDOB is strongly downregulated in DN-affected glomeruli, as well as in human and murine podocytes exposed to inflammatory cytokines. ALDOB reduction increases podocyte injury, while adenovirus-mediated ALDOB overexpression leads to substantial alleviation of renal injuries in a diabetic mouse model. Mechanistically, ALDOB reduction triggers the Akt/GSK/β-catenin signaling cascade within podocytes. Our findings reveal a novel non-metabolic role of glomerular ALDOB in protecting against podocyte injury and renal fibrosis.

Polymeric immunoglobulin receptor promotes Th2 immune response in the liver by increasing cholangiocytes derived IL-33: a diagnostic and therapeutic biomarker of biliary atresia

Biliary atresia (BA) is a devastating neonatal cholangiopathy with an unclear pathogenesis, and prompt diagnosis of BA is currently challenging. Proteomic and immunoassay analyses were performed with serum samples from 250 patients to find potential BA biomarkers. The expression features of polymeric immunoglobulin receptor (PIGR) were investigated using human biopsy samples, three different experimental mouse models, and cultured human biliary epithelial cells (BECs). Chemically modified small interfering RNA and adenovirus expression vector were applied for invivo silencing and overexpressing PIGR in a rotavirus-induced BA mouse model. Luminex-based multiplex cytokine assays and RNA sequencing were used to explore the molecular mechanism of PIGR involvement in the BA pathogenesis. Serum levels of PIGR, poliovirus receptor (PVR), and aldolase B (ALDOB) were increased in BA patients and accurately distinguished BA from infantile hepatitis syndrome (IHS). Combined PIGR and PVR analysis distinguished BA from IHS with an area under the receiver operating characteristic curve of 0.968 and an accuracy of 0.935. PIGR expression was upregulated in the biliary epithelium of BA patients; Th1 cytokines TNF-α and IFN-γ induced PIGR expression in BECs via activating NF-κB pathway. Silencing PIGR alleviated symptoms, reduced IL-33 expression, and restrained hepatic Th2 inflammation in BA mouse model; while overexpressing PIGR increased liver fibrosis and IL-33 expression, and boosted hepatic Th2 inflammation in BA mouse model. PIGR expression promotes the proliferation and epithelial-mesenchymal transition, and reduced the apoptosis of BECs. PIGR participated in BA pathogenesis by promoting hepatic Th2 inflammation via increasing cholangiocytes derived IL-33; PIGR has the value as a diagnostic and therapeutic biomarker of BA. This study was financially supported by the National Natural Science Foundation of China (82170529), the National Key R&D Program (2021YFC2701003), and the National Natural Science Foundation of China (82272022).

Ketogenic diet reshapes cancer metabolism through lysine β-hydroxybutyrylation.

Lysine β-hydroxybutyrylation (Kbhb) is a post-translational modification induced by the ketogenic diet (KD), a diet showing therapeutic effects on multiple human diseases. Little is known how cellular processes are regulated by Kbhb. Here we show that protein Kbhb is strongly affected by the KD through a multi-omics analysis of mouse livers. Using a small training dataset with known functions, we developed a bioinformatics method for the prediction of functionally important lysine modification sites (pFunK), which revealed functionally relevant Kbhb sites on various proteins, including aldolase B (ALDOB) Lys108. KD consumption or β-hydroxybutyrate supplementation in hepatocellular carcinoma cells increases ALDOB Lys108bhb and inhibits the enzymatic activity of ALDOB. A Kbhb-mimicking mutation (p.Lys108Gln) attenuates ALDOB activity and its binding to substrate fructose-1,6-bisphosphate, inhibits mammalian target of rapamycin signalling and glycolysis, and markedly suppresses cancer cell proliferation. Our study reveals a critical role of Kbhb in regulating cancer cell metabolism and provides a generally applicable algorithm for predicting functionally important lysine modification sites.

INTOLERÂNCIA HEREDITÁRIA À FRUTOSE: ETIOLOGIA E PRINCIPAIS CARACTERÍSTICAS CLÍNICAS, UMA REVISÃO DE LITERATURA

INTRODUCTION: Fructose is a monosaccharide found in various plant sources, honey, and fruits, as well as composing sucrose. After consumption, fructose absorption is facilitated by glucose transporters and metabolized in the liver, small intestine, and kidneys, where enzymes catalyze the breakdown of this monosaccharide. Hereditary Fructose Intolerance results from mutations in the ALDOB gene, which encodes the enzyme aldolase B, the primary enzyme involved in fructose metabolism, thus intolerance is a result of deficiency of this enzyme. OBJECTIVES: To review the etiological factors of Hereditary Fructose Intolerance, its main symptoms, and the treatment that should be performed. METHODOLOGY: Narrative literature review in biochemistry and genetics textbooks and in electronic databases (PubMed, Orphanet, Google Scholar, and Scielo) between July and September 2023. RESULTS: Hereditary Fructose Intolerance, estimated to have a prevalence of 1/40,000 in Europe, consists of aldolase B deficiency, responsible for fructose catabolism. Caused by genetic mutations, enzyme coding is affected, leading to the accumulation of fructose-1-phosphate in the liver, kidneys, and small intestine, which is harmful to these organs. Symptoms include nausea, vomiting, diarrhea, abdominal pain, flatulence, and hypoglycemia. Hepatic inflammation, renal overload, and tubular reabsorption difficulty also occur. It is noted that symptoms are not manifested in infants, as they usually occur during dietary diversification when foods containing fructose are ingested. CONCLUSION: Since it is a result of genetic mutations, there is no effective treatment as in the case of lactose intolerance, where aldolase B is not available in capsule form like lactase. Therefore, treatment involves dietary restriction of fructose, sucrose, sucralose, and sorbitol, with supplementation of essential vitamins present in foods containing these compounds being necessary. If left untreated, it can result in renal failure, metabolic acidosis, hepatic cirrhosis, coma, and death.

Characterization of a human induced pluripotent stem cell line (FDCHi015-A) derived from PBMCs of a patient harbouring ALDOB mutation

Hereditary fructose intolerance (HFI) is an autosomal recessive metabolic disease associated with a mutation in the aldolase B gene on chromosome 9q31. In this study, we generated a human-induced pluripotent stem cell (hiPSC) line, FDCHi015-A, from peripheral blood mononuclear cells (PBMCs) of a patient carrying the compound heterozygous mutations c.360_364delCAAA and c.1013C > T in exons 4 and 9 of the ALDOB gene, respectively. The iPSCs with the confirmed patient-specific mutation demonstrate pluripotency markers expression, a normal karyotype, and the ability to differentiate into derivatives of three germ layers.

Caspase-1 Cleavage of Aldolase B Impairs Hepatic Fructose Metabolism and Aggravates Chronic Viral Hepatitis

Abstract Of dietary monosaccharides, fructose is primarily metabolized by aldolase B (ALDOB) in the liver, whereas glucose is metabolized elsewhere in the body. It has been documented that overconsumption of dietary fructose, especially industrial fructose, associates significantly with advanced inflammation in chronic hepatitis C (CHC) patients. However, little is known about whether impaired fructolysis might attribute to CHC hepatopathogenesis. Herein we found that the level of ALDOB protein was significantly reduced in CHC patients and mice that were persistently infected by hepatitis C virus (HCV). In vitro, HCV infection activated caspase-1, and caspase-3 to a lesser extent, which proteolyzed ALDOB and blocked fructose metabolism in hepatocytes. Downregulation of ALDOB attenuated HCV replication, indicating an intrinsic anti-HCV role for homeostatic fructolysis. On the other hand, reduced ALDOB caused intracellular fructose 1-phosphate accumulation that provoked severe cellular toxicity through intracellular ATP depletion and heightened glycation, which was aggravated by HCV infection. Taken together, these results have unveiled that inflammatory activation of caspase-1 impairs homeostatic fructolysis and exacerbates liver damage.

Abstract 3084: Aldob regulates fructose metabolism to confer ferroptosis and immune response in colorectal cancer harboring microsatellite instability

Abstract Microsatellite instability (MSI) is a genetic alteration that occurs during cancer progression, specifically in colorectal cancer. Objective evidence demonstrates that colorectal cancer patients with MSI have better survival rates than those without MSI. Moreover, patients with both dMMR and MSI respond equally well to immunotherapy. We evaluated the MSI status of colorectal cancer specimens and identified an activation of aldolase B (ALDOB), the primary regulator of fructose metabolism, in the MSI group. Our analysis of the cancer cell panel revealed that the expression level of ALDOB in MSI+ cells (HCT116 and LoVo) was significantly higher than that in the microsatellite stable (MSS) group (SW480 and HT29). We also discovered a significant negative correlation between ALDOB and numerous dMMR-related genes, such as MLH1 and MSH2. We investigated how fructose concentration and pathway activation affected MSI occurrence. Our results demonstrated that abnormal fructose metabolism leaded to SLC7A11-mediated ferroptosis. SLC7A11 functioned as the active subunit and generated glutathione, GPX4, and lipid epoxides in response to transported cystine. This may explain the better clinical outcomes observed in colorectal patients with MSI. On the other hand, we also observed that ALDOB could increase certain immune ratios, such as CD4+ T cells and B cells. This aligns with the implementation of immunotherapy in the MSI community, which has been proven to yield positive effects. Consistent results were still being shown. Our study revealed significant increases in various chemokines and cytokines in media conditioned with fructose. It was interesting to note that fructose resulted in more significant changes than glucose. Based on the gathered evidence, it could be posited that ALDOB plays a crucial role as a promoter of fructose metabolism, leading to the induction of ferroptosis and immune responses in MSI colorectal cancer. The findings shed new light on known consequences and provide new avenues of information. Citation Format: Yu-Chan Chang, Chi-Long Chen. Aldob regulates fructose metabolism to confer ferroptosis and immune response in colorectal cancer harboring microsatellite instability [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3084.

Associations between ALDOB polymorphisms and intrahepatic cholestasis of pregnancy susceptibility in the Chinese Han population.

To research the associations between fructose-bisphosphate aldolase B (ALDOB) gene polymorphisms and intrahepatic cholestasis of pregnancy (ICP) risk. Whole-genome sequencing (WGS) was performed to detect ALDOB polymorphisms. Five web-available tools were employed to predict the effect of the site variant on the protein. Protein structure comparisons between the reference and ALDOB-modified samples were performed by SWISS-MODEL and Chimera 1.14rc, respectively. We identified 28 genetic variants in the ALDOB gene. When the cut-off value of minor allele frequency (MAF) of loci was 0.001 in four databases, five missense variants, including rs747604233, rs759204107, rs758242037, rs371526091 and rs77718928, were reserved for subsequent analysis. These variants were absent from the 1029 control individuals. The influence of all five variants on protein function was predicted to be damaging by the abovementioned five prediction software programs. Bioinformatics analysis demonstrated that these five missense variants were highly conserved among vertebrates. Compared to the wild-type protein structure, all five mutated protein structures showed a slight change in the chemical bond lengths of the enzyme activity domains. The combined clinical data indicate that the variant group had a significantly older age (p = 0.038), a higher level of indirect bilirubin (IDBIL, p = 0.033), and lower counts of white blood cells (WBCs, p = 7.38E-05) and platelets (PLTs, p = 0.018) than the wild-type group. This is the first study to examine the associations between ALDOB polymorphisms and ICP disease in 249 Chinese patients with ICP. Our present study expands the understanding of the pathogenesis of ICP.

Fructose Metabolism Defects in Indian Children - Uncommon or Under-reported? - a Case Series

Objective − The objective of this case series is to report the varied manifestations of fructose metabolic defects across various age groups in Indian children.Case Series − We report 3 cases of fructose intolerance (1 male, 2 female) presenting at 17 months, 3.3 years and 10 months, with hypoglycaemia, recurrent metabolic acidosis, and abdominal distension with hepatomegaly, respectively. Weight was more affected than height in all of them: 1 child had hypoglycaemia and 2 of them had metabolic acidosis. Genetic tests confirmed the diagnosis with 2 patients having mutations in the FBP-1 gene and 1 mutation in the ALDO-B gene. Catch up growth was documented with resolution of symptoms in all with a fructose free diet.Conclusion − Fructose metabolic defect is a wide spectrum disorder which should be kept in mind in children with failure to thrive, recurrent hypoglycaemia and/or metabolic acidosis.

ALDOB/KAT2A interactions epigenetically modulate TGF-β expression and T cell functions in hepatocellular carcinogenesis.

Cross talk between tumor cells and immune cells enables tumor cells to escape immune surveillance and dictate responses to immunotherapy. Previous studies have identified that downregulation of the glycolytic enzyme fructose-1,6-bisphosphate aldolase B (ALDOB) in tumor cells orchestrated metabolic programming to favor HCC. However, it remains elusive whether and how ALDOB expression in tumor cells affects the tumor microenvironment in HCC. We found that ALDOB downregulation was negatively correlated with CD8 + T cell infiltration in human HCC tumor tissues but in a state of exhaustion. Similar observations were made in mice with liver-specific ALDOB knockout or in subcutaneous tumor models with ALDOB knockdown. Moreover, ALDOB deficiency in tumor cells upregulates TGF-β expression, thereby increasing the number of Treg cells and impairing the activity of CD8 + T cells. Consistently, a combination of low ALDOB and high TGF-β expression exhibited the worst overall survival for patients with HCC. More importantly, the simultaneous blocking of TGF-β and programmed cell death (PD) 1 with antibodies additively inhibited tumorigenesis induced by ALDOB deficiency in mice. Further mechanistic experiments demonstrated that ALDOB enters the nucleus and interacts with lysine acetyltransferase 2A, leading to inhibition of H3K9 acetylation and thereby suppressing TGFB1 transcription. Consistently, inhibition of lysine acetyltransferase 2A activity by small molecule inhibitors suppressed TGF-β and HCC. Our study has revealed a novel mechanism by which a metabolic enzyme in tumor cells epigenetically modulates TGF-β signaling, thereby enabling cancer cells to evade immune surveillance and affect their response to immunotherapy.

Aldolase B-driven lactagenesis and CEACAM6 activation promote cell renewal and chemoresistance in colorectal cancer through the Warburg effect

Colorectal cancer (CRC) is a prevalent malignancy worldwide and is associated with a high mortality rate. Changes in bioenergy metabolism, such as the Warburg effect, are often observed in CRC. Aldolase B (ALDOB) has been identified as a potential regulator of these changes, but its exact role in CRC cell behavior and bioenergetic homeostasis is not fully understood. To investigate this, two cohorts of CRC patients were analyzed independently. The results showed that higher ALDOB expression was linked to unfavorable prognosis, increased circulating carcinoembryonic antigen (CEA) levels, and altered bioenergetics in CRC. Further analysis using cell-based assays demonstrated that ALDOB promoted cell proliferation, chemoresistance, and increased expression of CEA in CRC cells. The activation of pyruvate dehydrogenase kinase-1 (PDK1) by ALDOB-induced lactagenesis and secretion, which in turn mediated the effects on CEA expression. Secreted lactate was found to enhance lactate dehydrogenase B (LDHB) expression in adjacent cells and to be a crucial modulator of ALDOB-mediated phenotypes. Additionally, the effect of ALDOB on CEA expression was downstream of the bioenergetic changes mediated by secreted lactate. The study also identified CEA cell adhesion molecule-6 (CEACAM6) as a downstream effector of ALDOB that controlled CRC cell proliferation and chemoresistance. Notably, CEACAM6 activation was shown to enhance protein stability through lysine lactylation, downstream of ALDOB-mediated lactagenesis. The ALDOB/PDK1/lactate/CEACAM6 axis plays an essential role in CRC cell behavior and bioenergetic homeostasis, providing new insights into the involvement of CEACAM6 in CRC and the Warburg effect. These findings may lead to the development of new treatment strategies for CRC patients.

Comparative transcriptome analysis reveals mechanisms of restriction feeding on lipid metabolism in ducks

Presently, excessive fat deposition is the main reason to limit the development of duck industry. In the production, the methods of restricted feeding (RF) were widely used to reduce the lipid deposition of ducks. The liver (L), abdominal adipose (AA), and subcutaneous adipose (SA) were the main tissues of lipid metabolism and deposition of ducks. However, the mechanisms of lipid metabolism and deposition of ducks under RF have not been fully clarified. In this study, in order to better understand the mechanisms of lipid metabolism and deposition in ducks under RF, a total of 120 male Nonghua ducks were randomly divided into a free feeding group (FF, n=60) and RF group (RF, n=60), then comparative transcriptomic analysis of L, AA, and SA between FF (n=3) and RF (n=3) ducks was performed at 56 d of age. Phenotypically, L, AA, and SA index of FF group was higher than that in RF group. There were 279, 390, and 557 differentially expressed genes (DEGs) in L, AA, and SA. Functional enrichment analysis revealed that ECM-receptor interaction and metabolic pathways were significantly enriched in L, AA, and SA. Lipid metabolism-related pathways including fatty acid metabolism, unsaturated fatty acid synthesis, and steroidogenesis were significantly enriched in AA and SA. Moreover, through integrated analysis weighted gene coexpression network (WGCNA) and protein-protein interaction network, 10 potential candidate genes involved in the ECM-receptor interaction and lipid metabolism pathways were identified, including 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2), aldolase B (ALDOB), formimidoyltransferase cyclodeaminase(FTCD), phosphoenolpyruvate carboxykinase 1 (PCK1), tyrosine aminotransferase (TAT), stearoyl-CoA desaturase (SCD), squalene epoxidase (SQLE), phosphodiesterase 4B (PDE4B), choline kinase A (CHKA), and elongation of very-long-chain fatty acids-like 2 (ELOVL2), which could play a key role in lipid metabolism and deposition of ducks under RF. Our study reveals that the liver might regulate the lipid metabolism of abdominal adipose and subcutaneous adipose through ECM-receptor interaction and metabolic pathways (fatty acid metabolism, unsaturated fatty acid synthesis, and steroid synthesis), thus to reduce the lipid deposition of ducks under RF. These results provide novel insights into the avian lipid metabolism and will help better understand the underlying molecular mechanisms.

Pan-cancer analysis of aldolase B gene as a novel prognostic biomarker for human cancers.

Aldolase B (ALDOB) gene is essential for the process of glycolysis and differentially expressed in cancers. The aims of this study were to explore the potential role of ALDOB in pan-cancer, in order to deepen the research on the pathological mechanism of cancer. Hence, we used several online tools (TIMER2, GEPIA2, UALCAN, cBioPortal, and MXPRESS) and R language to identify the correlation between the ALDOB expression and survival analysis, genetic alteration, DNA methylation, and immune cell infiltration based on The Cancer Genome Atlas project. The results showed that ALDOB was lowly expressed in pan-cancer. Survival analysis revealed that low expression of ALDOB was markedly related with poor clinical prognosis, while the genetic alteration within ALDOB changed along with the difference of overall survival (OS) and disease-free survival (DFS) prognosis in several cancers. A possible relationship between DNA methylation and ALDOB expression for several tumors was found. Besides, ALDOB expression was confirmed to be associated with tumor immune cell infiltration, especially in breast invasive carcinoma (BRCA), esophageal carcinoma (ESCA), and testicular germ cell tumors (TGCT) cases. Further, the enrichment analysis demonstrated that metabolic pathway was closely related to ALDOB expression. Our results provide a comprehensive pan-cancer analysis and suggest ALDOB could act as a promising tumor predictive biomarker for human cancer.

Fructose-1,6-bisphosphatase is a nonenzymatic safety valve that curtails AKT activation to prevent insulin hyperresponsiveness

Insulin inhibits gluconeogenesis and stimulates glucose conversion to glycogen and lipids. How these activities are coordinated to prevent hypoglycemia and hepatosteatosis is unclear. Fructose-1,6-bisphosphatase (FBP1) is rate controlling for gluconeogenesis. However, inborn human FBP1 deficiency does not cause hypoglycemia unless accompanied by fasting or starvation, which also trigger paradoxical hepatomegaly, hepatosteatosis, and hyperlipidemia. Hepatocyte FBP1-ablated mice exhibit identical fasting-conditional pathologies along with AKT hyperactivation, whose inhibition reversed hepatomegaly, hepatosteatosis, and hyperlipidemia but not hypoglycemia. Surprisingly, fasting-mediated AKT hyperactivation is insulin dependent. Independently of its catalytic activity, FBP1 prevents insulin hyperresponsiveness by forming a stable complex with AKT, PP2A-C, and aldolase B (ALDOB), which specifically accelerates AKT dephosphorylation. Enhanced by fasting and weakened by elevated insulin, FBP1:PP2A-C:ALDOB:AKT complex formation, which is disrupted by human FBP1 deficiency mutations or a C-terminal FBP1 truncation, prevents insulin-triggered liver pathologies and maintains lipid and glucose homeostasis. Conversely, an FBP1-derived complex disrupting peptide reverses diet-induced insulin resistance.

ALDOB represents a potential prognostic biomarker for patients with clear cell renal cell carcinoma.

Previous studies have shown that aldolase B (ALDOB) might play controversial roles in multiple types of cancer, which could act as a cancer-promoting factor or a cancer-inhibiting factor depending on the subtype of the cancer. However, the role of ALDOB in clear cell renal cell carcinoma (ccRCC) patients has not been clearly elucidated. Therefore, this study aimed to comprehensively explore the expression level, prognostic value, functional enrichment, immune infiltration, and N6-methyladenosine (m6A) modification of ALDOB in ccRCC patients. A total of 1,070 ccRCC tissues and 409 normal tissues from the Gene Expression Omnibus (GEO) database, The Cancer Genome Atlas (TCGA) database, and the ArrayExpress database were enrolled to evaluate the expression level and prognostic value of ALDOB in ccRCC. The Kaplan-Meier survival curves and the Log-Rank test were performed to assess the prognostic value. The univariate and multivariate Cox regression analysis were used to identify the independent prognostic predictors in ccRCC patients. In addition, R version 4.2.0 with its suitable packages were used to perform the functional enrichment analysis, immune infiltration analysis, and m6A methylation analysis. Statistical significance was set at the P value <0.05. The expression level of ALDOB was significantly down-regulated in ccRCC compared to normal tissue, and the ALDOB expression level was noticeably correlated with T stage, M stage, and histologic grade of patients with ccRCC. The survival analysis revealed that ALODB was the independent predictor of overall survival (OS), disease-specific survival (DSS), and progression-free survival (PFS) of ccRCC patients. In addition, the functional enrichment analysis showed that ALDOB and its related genes were mainly involved in the metabolism and metabolic pathways of multiple substances, including glycolysis, gluconeogenesis, and fatty acid degradation. Finally, the immune infiltration analysis and the m6A methylation analysis suggested that ALDOB was closely correlated with the infiltration abundance of immune cells and stromal cells in the tumor microenvironment and several types of m6A regulators in ccRCC. As a potential prognostic biomarker for patients with ccRCC, downregulation of ALDOB was closely associated with the clinicopathological features, poor prognosis, immune infiltration, and m6A modification in ccRCC patients.

Aldolase B attenuates clear cell renal cell carcinoma progression by inhibiting CtBP2.

Aldolase B (ALDOB), a glycolytic enzyme, is uniformly depleted in clear cell renal cell carcinoma (ccRCC) tissues. We previously showed that ALDOB inhibited proliferation through a mechanism independent of its enzymatic activity in ccRCC, but the mechanism was not unequivocally identified. We showed that the corepressor C-terminal-binding protein 2 (CtBP2) is a novel ALDOB-interacting protein in ccRCC. The CtBP2-to-ALDOB expression ratio in clinical samples was correlated with the expression of CtBP2 target genes and was associated with shorter survival. ALDOB inhibited CtBP2-mediated repression of multiple cell cycle inhibitor, proapoptotic, and epithelial marker genes. Furthermore, ALDOB overexpression decreased the proliferation and migration of ccRCC cells in an ALDOB-CtBP2 interaction-dependent manner. Mechanistically, our findings showed that ALDOB recruited acireductone dioxygenase 1, which catalyzes the synthesis of an endogenous inhibitor of CtBP2, 4-methylthio 2-oxobutyric acid. ALDOB functions as a scaffold to bring acireductone dioxygenase and CtBP2 in close proximity to potentiate acireductone dioxygenase-mediated inhibition of CtBP2, and this scaffolding effect was independent of ALDOB enzymatic activity. Moreover, increased ALDOB expression inhibited tumor growth in a xenograft model and decreased lung metastasis in vivo. Our findings reveal that ALDOB is a negative regulator of CtBP2 and inhibits tumor growth and metastasis in ccRCC.

Genomic analysis of lean individuals with NAFLD identifies monogenic disorders in a prospective cohort study

Lean patients with non-alcoholic fatty liver disease (NAFLD) represent 10-20% of the affected population and may have heterogeneous drivers of disease. We have recently proposed the evaluation of patients with lean NAFLD without visceral adiposity for rare monogenic drivers of disease. Here, we aimed to validate this framework in a well-characterised cohort of patients with biopsy-proven NAFLD by performing whole exome sequencing. This prospective study included 124 patients with biopsy-proven NAFLD and paired liver biopsies who underwent standardised research visits including advanced magnetic resonance imaging (MRI) assessment of liver fat and stiffness. Six patients with lean NAFLD were identified and underwent whole exome sequencing. Two lean patients (33%) were identified to have monogenic disorders. The lean patients with monogenic disorders had similar age, and anthropometric and MRI characteristics to lean patients without a monogenic disorder. Patient 1 harbours a rare homozygous pathogenic mutation in ALDOB (aldolase B) and was diagnosed with hereditary fructose intolerance. Patient 2 harbours a rare heterozygous mutation in apolipoprotein B (APOB). The pathogenicity of this APOB variant (p.Val1856CysfsTer2) was further validated in the UK Biobank and associated with lower circulating APOB levels (beta= -0.51g/L, 95% CI -0.65 to -0.36g/L, p= 1.4×10-11) and higher liver fat on MRI (beta=+10.4%, 95% CI 4.3-16.5%, p= 8.8×10-4). Hence, patient 2 was diagnosed with heterozygous familial hypobetalipoproteinaemia. In this cohort of well-characterised patients with lean NAFLD without visceral adiposity, 33% (2/6) had rare monogenic drivers of disease, highlighting the importance of genomic analysis in this NAFLD subtype. Although most people with non-alcoholic fatty liver disease (NAFLD) are overweight or obese, a subset are lean and may have unique genetic mutations that cause their fatty liver disease. We show that 33% of study participants with NAFLD who were lean harboured unique mutations that cause their fatty liver, and that these mutations had effects beyond the liver. This study demonstrates the value of genetic assessment of NAFLD in lean individuals to identify distinct subtypes of disease.

ALDOB plays a tumor-suppressive role by inhibiting AKT activation in gastric cancer.

Enhanced aerobic glycolysis has been one of the cancer hallmarks. Cancerous cells develop certain alterations during glucose metabolism for supporting their infinite growth requirement and metastasis. Therefore, targeting metabolism, for instance, crucial glycolytic enzymes, will provide a novel therapeutic strategy to treat cancer. Aldolase B (ALDOB), as a glycolytic enzyme, plays a contentious role in cancers and can either act against the tumor or as an oncogenic enzyme. The precise role of ALDOB in gastric cancer (GC) and the endogenous process is elusive and needs further exploration. This investigation revealed that ALDOB expression was markedly decreased in GC tissues. Furthermore, ALDOB inhibition was notably linked with tumor size, depth of tumor invasion, lymph node metastasis (LNM), tumor node metastases (TNM) staging, and substandard prognosis of GC. The assessment of loss- and gain-of-function indicated that ALDOB inhibited the growth and the migrative ability of GC cells, suggesting its anti-tumor role. Mechanistic studies revealed that ALDOB modulates the AKT signaling pathway. The increase in growth and cells' ability to migrate stimulated by ALDOB inhibition was partially impaired in cells under the influence of AKT inhibitors. The overall data highlights a novel target, the ALDOB/AKT signaling axis for the treatment of GC.

Prognostic values of ALDOB expression and 18F-FDG PET/CT in hepatocellular carcinoma.

The glycolytic enzyme fructose 1,6-bisphosphate aldolase B (ALDOB) is aberrantly expressed and impacts the prognosis in hepatocellular carcinoma (HCC). Hepatic ALDOB loss leads to paradoxical upregulation of glucose metabolism, favoring hepatocellular carcinogenesis. Nevertheless, the relationship between ALDOB expression and 18F-fluorodeoxyglucose (18F-FDG) uptake, and their effects on HCC prognosis remain unclear. We evaluated whether ALDOB expression is associated with 18F-FDG uptake and their impacts on HCC prognosis prediction. Changes in ALDOB expression levels and the prognostic values in HCC were analyzed using data from The Cancer Genome Atlas (TCGA) database. Ultimately, 34 patients with HCC who underwent 18F-FDG positron emission tomography/computed tomography (PET/CT) preoperatively were enrolled in this retrospective study. ALDOB expression was determined using immunohistochemistry (IHC) staining, and the maximum standardized uptake value (SUVmax) of HCC was calculated from the 18F-FDG PET/CT scans. The relationship between ALDOB expression and SUVmax was examined, and their impacts on overall survival were evaluated using Cox proportional hazards models and Kaplan-Meier survival analysis. ALDOB overexpression in HUH7 and 7721 cells was used to analyze its role in tumor metabolism. According to TCGA database, the ALDOB mRNA level was downregulated in HCC compared to normal tissue, and significantly shortened overall survival in HCC patients. ALDOB protein expression was similarly decreased in IHC findings in HCC than that in adjacent normal tissues (P<0.05) and was significantly associated with tumor size (P<0.001), high tumor-node-metastasis stage (P=0.022), and elevated SUVmax (P=0.009). ALDOB expression in HCC was inversely correlated with SUVmax (r=-0.454; P=0.012), and the optimal SUVmax cutoff value for predicting its expression was 4.15. Prognostically, low ALDOB expression or SUVmax ≥3.9 indicated shorter overall survival time in HCC. Moreover, COX regression analysis suggested high SUVmax as an independent prognostic risk factor for HCC (P=0.036). HCC patients with negative ALDOB expression and positive SUVmax (≥3.9) were correlated with worse prognosis. ALDOB overexpression in HCC cells significantly decreases 18F-FDG uptake and lactate production. SUVmax in HCC patients is inversely correlated with ALDOB expression, and 18F-FDG PET/CT may be useful for ALDOB status prediction. The combined use of ALDOB expression and 18F-FDG PET/CT data can provide additional information on disease prognosis in HCC patients.

Abstract IA04: Metabolic control of HCC initiation and progression

Abstract Non-alcoholic steatohepatitis (NASH) is quickly becoming the leading HCC etiology. NASH can lead to HCC by altering liver metabolism, inducing oncogenic mutations, causing tumor promoting inflammation as well as the immunosuppression of anti-HCC immunity. We have established an accurate model for studying NASH-induced HCC development, the MUP-uPA mouse, and used it to show that elevated TNF production by liver macrophages contributes to both NASH and HCC progression. The major cause of TNF induction during NASH is gut-derived endotoxin, whose infiltration into the portal circulation is enhanced by barrier disrupting diets that are high in fats or fructose. By disrupting autophagy and activating NF-kB, HFD feeding of MUP-uPA mice results in accumulation of p62, the major constituent of Mallory-Denk bodies, within hepatocytes. Accumulation of p62 is not required for induction of hepatosteatosis but it greatly accelerates and enhances NASH to HCC progression through the activation of NRF2 and mTORC1. Conditional activation of NRF2 in hepatocytes results in hepatomegaly due to induction of EGF and PDGF family members as well as altered liver metabolism, in part by triggering the degradation of fructose-1,6 bisphosphate phosphatase (FBP1). FBP1 is rate limiting for gluconeogenesis and its germ-line inherited deficiency results in a complex metabolic disorder that includes hypoglycemia, lactic acidosis, hepatomegaly, hepatosteatosis, hyperlipidemia and liver damage and is manifested only in response to glucose starvation. By generating Fbp1ΔHep mice, we found that FBP1 has enzymatic and non-enzymatic activities, the latter of which are due to formation of a multiprotein complex with aldolase B (ALDOB) and PP2A-C that interacts with AKT, dephosphorylates it and inhibits its activation. By inhibiting AKT activation, FBP1 and ALDOB suppress HCC development. Citation Format: Michael Karin, Li Gu, Yahui Zhu. Metabolic control of HCC initiation and progression [abstract]. In: Proceedings of the AACR Special Conference: Advances in the Pathogenesis and Molecular Therapies of Liver Cancer; 2022 May 5-8; Boston, MA. Philadelphia (PA): AACR; Clin Cancer Res 2022;28(17_Suppl):Abstract nr IA04.