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BACKGROUND RESULTS CONCLUSIONS The aqueous extraction of sesame oil is a traditional process that generates a large amount of melanoidins. However, little is known about the characteristics and bioactive functions of these melanoidins.Electronic tongue, fluorescence emission spectroscopy, and Fourier transform infrared spectroscopy analyses indicated that melanoidins from sesame residues (MELs) are brown macromolecular compounds with protein skeletons and heteroaromatic ring structures, a bitter taste, and instability in strong oxidative and reductive environments. The MELs demonstrated inhibitory effects on α‐glucosidase, α‐amylase and pancreatic lipase in vitro. These MELs mitigated weight loss in mice with type 2 diabetes (T2DM), reduced their fasting blood glucose to 54.73% (500 mg kg−1 day−1) of the initial value, increased the glycogen levels in the liver and skeletal muscles, lowered blood lipid levels, and protected the liver. Western blot analysis revealed that MELs inhibited the activities of enzymes such as PEPCK, FBPase, and G6Pase through the IRS‐1/PI3K/Akt and AMPK pathways, increased the activity of the enzymes hexokinase (HK) and pyruvate kinase (PK), enhanced liver glycolytic ability, and promoted liver glycogen synthesis, thereby reducing blood glucose levels in T2DM mice. Moreover, MELs reduced the ratio of Firmicutes to Bacteroides (F/B) in the intestines of T2DM mice, increased the relative abundance of beneficial bacteria such as Lactobacillus, Coprococcus, and Ruminococcus, and reduced the propionic acid content.Melanoidins can regulate T2DM by activating the IRS‐1/PI3K/Akt and AMPK‐signaling pathways and ameliorating gut microbiota imbalances in T2DM mice. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Background: Aerobic glycolysis is a tumor cell phenotype and a hallmark in cancer research. The alternative splicing of the pyruvate kinase M (PKM) gene regulates the expressions of PKM1/2 isoforms and the aerobic glycolysis of tumors. Polypyrimidine tract binding protein (PTBP1) is critical in this process; however, its impact and underlying mechanisms in colorectal cancer (CRC) remain unclear. This study aimed to investigate the role of PTBP1 crotonylation in CRC progression. Methods: The crotonylation levels of PTBP1 in human CRC tissues and cell lines were analyzed using crotonylation proteomics and immunoprecipitation. The main crotonylation sites were identified by immunoprecipitation and immunofluorescent staining. The glycolytic capacities of CRC cells were evaluated by measuring the glucose uptake, lactate production, extracellular acidification rate, and glycolytic proton efflux rate. The role and mechanism of PTBP1 crotonylation in PKM alternative splicing were determined by Western blot, quantitative real-time PCR (RT-qPCR), RNA immunoprecipitation, and immunoprecipitation. The effects of PTBP1 crotonylation on the behaviors of CRC cells and CRC progression were assessed using CCK-8, colony formation, cell invasion, wound healing assays, xenograft model construction, and immunohistochemistry. Results: The crotonylation level of PTBP1 was elevated in human CRC tissues compared to peritumor tissues. In CRC tissues and cells, PTBP1 was mainly crotonylated at K266 (PTBP1 K266-Cr), and lysine acetyltransferase 2B (KAT2B) acted as the crotonyltranferase. PTBP1 K266-Cr promoted glycolysis and lactic acid production, increasing the PKM2/PKM1 ratio in CRC tissues and cells. Mechanistically, PTBP1 K266-Cr enhanced the interaction of PTBP1 with heterogeneous nuclear ribonucleoprotein A1 and A2 (hnRNPA1/2), thus affecting the PKM alternative splicing. PTBP1 K266-Cr facilitated CRC cell proliferation, migration, and metastasis in vitro and in vivo. Pathologically, a high level of PTBP1 K266-Cr was associated with poor prognosis in CRC patients. Conclusions: Crotonylation of PTBP1 coordinates tumor cell glycolysis and promotes CRC progression by regulating PKM alternative splicing and increasing PKM2 expression. [ABSTRACT FROM AUTHOR]

Sodium Danshensu (SDSS) is extracted from Salvia miltiorrhiza and has many pharmacological effects. However, little is known about its effects on muscle fiber formation and metabolism. Here, we aimed to investigated the role and molecular mechanisms of SDSS in modulating the formation of skeletal muscle fiber. C2C12 cells were incubated in differentiation medium with or without SDSS for 4 days. C57BL/6 mice were orally administered SDSS by gavage once a day for 8 weeks. Grip strength, treadmill, muscle weight, western blotting, qPCR, immunofluorescence staining and H&E staining were performed. SDSS target proteins were searched through drug affinity responsive target stability (DARTS) and mass spectrometry analysis. Furthermore, molecular docking was carried out for Pyruvate kinase M1 (PKM1). The effect of PKM1 on myosin heavy chain (MyHCs) gene expression was verified by knockdown of PKM1 experiment. SDSS induced oxidative muscle fiber-related gene expression, and inhibited glycolytic fiber-related gene expression in C2C12 cells. Muscle mass, the percentage of slow oxidative fibers, succinic dehydrogenase activity, muscle endurance, glucose tolerance, and the expression of the MyHC1 and MyHC2a genes increased while MyHC2b expression, lactate dehydrogenase activity, and the percentage of glycolytic muscle fibers decreased in SDSS-treated mice. Mechanistically, SDSS bound to the pyruvate kinase PKM1 and significantly repressed its activity. PKM1 inhibited MyH C1 and MyHC2 a expression but promoted MyHC2b expression. SDSS also significantly attenuated the effects of PKM1 on muscle fiber-related gene expression in C2C12 cells. Our findings indicate that SDSS promotes muscle fiber transformation from the glycolytic type to the oxidative type by inhibiting PKM1 activity, which provide a new idea for treating muscle atrophy, muscle metabolism diseases and improving animal meat production. [ABSTRACT FROM AUTHOR]

Introduction: Myelodysplastic syndromes/neoplasms (MDS) are a heterogeneous group of hematologic malignancies that are stratified into high-risk (HR-MDS) and low-risk (LR-MDS) categories. Until recently, LR-MDS has been typically managed by supportive measures and erythropoiesis-stimulating agents (ESAs); whereas management of HR-MDS typically included hypomethylating agents and allogeneic hematopoietic stem cell transplant. However, the limited rates and durations of response observed with these interventions prompted the search for targeted therapies to improve the outcomes among patients with MDS. Areas covered: Here, we review the current landscape of targeted therapies in MDS. These include pyruvate kinase and hypoxia-inducible factor (HIF) activators; TGF-beta, telomerase, BCL2 and isocitrate dehydrogenase (IDH) inhibitors; as well as novel approaches targeting inflammation, pyroptosis, immune evasion, and RNA splicing machinery. Expert opinion: This review highlights the progress and challenges in MDS treatment. Despite some promising results, many therapies remain in early development or have faced setbacks, emphasizing the need for a more comprehensive understanding of the disease's pathobiology. Continued research into targeted therapies, homogenous clinical trial designs, as well as increased incorporation of molecular prognostic tools and artificial intelligence into trial design are essential for developing effective treatments for MDS and improving patient outcomes. [ABSTRACT FROM AUTHOR]

Pyruvate kinase (PK) deficiency is a rare, hereditary, hemolytic anemia caused by mutations in the PKLR gene encoding the PK enzyme. Mitapivat (previously designated AG‐348) is a first‐in‐class, oral, allosteric activator of PK. We report results from 5 Phase 1 trials in healthy adults to characterize and compare mitapivat pharmacokinetics across different formulations and analyze food effects on mitapivat bioavailability (Studies 1‐5). Pharmacokinetic assessments were peak exposure, total exposure, time to maximum plasma concentration of mitapivat, and relative bioavailability (where appropriate). Plasma total exposure of mitapivat was similar in the fasted and fed (high‐fat meal or different soft foods) states after capsule, tablet, and pediatric granule formulations. Although mitapivat administration with food reduced the rate of mitapivat absorption (delay in time to maximum plasma concentration; reduction in maximum concentration) versus dosing under fasted conditions, this was not considered clinically relevant, given the lack of effect on total mitapivat exposure. Consequently, the administration instructions for mitapivat relating to food state that “patients may take mitapivat tablets with or without food.” These findings will continue to inform clinical studies and development of mitapivat in adult and pediatric patients with hemolytic anemias and may help inform healthcare professionals on mitapivat dosing/administration recommendations in clinical practice. [ABSTRACT FROM AUTHOR]

Simple Summary: Adipose tissue has A vital impact on animal production efficiency. Postnatal development plays a key role in regulating adipose tissue function; however, the underlying molecular mechanisms of this early-life programming of adipose tissue remain unclear. In this study, we analyzed the transcriptomes of adipose tissue between newborn and twenty-one days old Laiwu piglets, which is a Chinese indigenous breed characterized with high fat content. Our findings revealed a significant change in metabolic pattern as well as transcriptional and translational control in adipose tissue during this postnatal period, providing a better understanding of the development and function regulation of adipose tissue, improving pig production efficiency. Adipose tissue plays an important role in pig production efficiency. Studies have shown that postnatal development has a vital impact on adipose tissue; however, the mechanisms behind pig adipose tissue early-life programming remain unknown. In this study, we analyzed the transcriptomes of the subcutaneous adipose tissue (SAT) of 1-day and 21-day old Laiwu piglets. The results showed that the SAT of Laiwu piglets significantly increased from 1-day to 21-day, and transcriptome analysis showed that there were 2352 and 2596 differentially expressed genes (DEGs) between 1-day and 21-day SAT in male and female piglets, respectively. Expression of genes in glycolysis, gluconeogenesis, and glycogen metabolism such as pyruvate kinase M1/2 (PKM), phosphoenolpyruvate carboxy kinase 1 (PCK1) and amylo-alpha-1, 6-glucosidase, 4-alpha-glucanotransferase (AGL) were significantly different between 1-day and 21-day SAT. Genes in lipid uptake, synthesis and lipolysis such as lipase E (LIPE), acetyl-CoA carboxylase alpha (ACACA), Stearoyl-CoA desaturase (SCD), and 3-hydroxy-3-methylglutaryl-CoA synthase 1 (HMGCS1) were also differentially expressed. Functional analysis showed enrichment of DEGs in transcriptional regulation, protein metabolism and cellular signal transduction. The protein–protein interaction (PPI) networks of these DEGs were analyzed and potential hub genes in these pathways were identified, such as transcriptional factors forkhead box O4 (FOXO4), CCAAT enhancer binding protein beta (CEBPB) and CCAAT enhancer binding protein delta (CEBPD), signal kinases BUB1 mitotic checkpoint serine/threonine kinase (BUB1) and cyclin-dependent kinase 1 (CDK1), and proteostasis-related factors ubiquitin conjugating enzyme E2 C (UBE2C) and cathepsin D (CTSD). Moreover, we further analyzed the transcriptomes of SAT between genders and the results showed that there were 54 and 72 DEGs in 1-day and 21-day old SAT, respectively. Genes such as KDM5D and KDM6C showed gender-specific expression in 1-day and 21-day SAT. These results showed the significant changes in SAT between 1-day and 21-day in male and female Laiwu pigs, which would provide information to comprehensively understand the programming of adipose tissue early development and to regulate adipose tissue function. [ABSTRACT FROM AUTHOR]

Oral cancer, representing 2–4% of all cancer cases, predominantly consists of Oral Squamous Cell Carcinoma (OSCC), which makes up 90% of oral malignancies. Early detection of OSCC is crucial, and identifying specific proteins in saliva as biomarkers could greatly improve early diagnosis. Here, we proposed a strategy to pinpoint candidate biomarkers. Starting from a list of salivary proteins detected in 10 OSCC patients and 20 healthy controls, we combined a univariate approach and a multivariate approach to select candidates. To reduce the number of proteins selected, a Protein–Protein Interaction network was built to consider only connected proteins. Then, an over-representation analysis (ORA) determined the enriched pathways. The network from 172 differentially abundant proteins highlighted 50 physically connected proteins, selecting relevant candidates for targeted experimental validations. Notably, proteins like Heat shock 70 kDa protein 1A/1B, Pyruvate kinase PKM, and Phosphoglycerate kinase 1 were suggested to be differentially regulated in OSCC patients, with implications for oral carcinogenesis and tumor growth. Additionally, the ORA revealed enrichment in immune system, complement, and coagulation pathways, all known to play roles in tumorigenesis and cancer progression. The employed method has successfully identified potential biomarkers for early diagnosis of OSCC using an accessible body fluid. [ABSTRACT FROM AUTHOR]

Breast cancer (BC) is a prevalent malignant tumor in women, and its incidence has been steadily increasing in recent years. Compared with other types of cancer, it has the highest mortality and morbidity rates in women. So, it is crucial to investigate the underlying mechanisms of BC development and identify specific therapeutic targets. Pyruvate kinase M2 (PKM2), an important metabolic enzyme in glycolysis, has been found to be highly expressed in BC. It can also move to the nucleus and interact with various transcription factors and proteins, including hypoxia-inducible factor-1a (HIF-1a), signal transducer and activator of transcription 3 (STAT3), b-catenin, cellular-myelocytomatosis oncogene (c-Myc), nuclear factor kappa-light-chain enhancer of activated B cells (NF-kB), and mammalian sterile 20-like kinase 1 (MST1). This interaction leads to non-metabolic functions that control the cell cycle, proliferation, apoptosis, migration, invasion, angiogenesis, and tumor microenvironment in BC. This review provides an overview of the latest advancements in understanding the interactions between PKM2 and different transcription factors and proteins that influence the initiation and progression of BC. It also examined how natural drugs and noncoding RNAs affect various biological processes in BC cells through the regulation of the non-metabolic enzyme functions of PKM2. The findings provide valuable insights for improving the prognosis and developing targeted therapies for BC in the coming years. [ABSTRACT FROM AUTHOR]

Endothelial cell (EC) senescence and vascular aging are important hallmarks of chronic metabolic diseases. An improved understanding of the precise regulation of EC senescence may provide novel therapeutic strategies for EC and vascular aging-related diseases. This study examined the potential functions of Spinster homolog 2 (SPNS2) in EC senescence and vascular aging. We discovered that the expression of SPNS2 was significantly lower in older adults, aged mice, hydrogen peroxide-induced EC senescence models and EC replicative senescence model, and was correlated with the expression of aging-related factors. in vivo experiments showed that the EC-specific knockout of SPNS2 markedly aggravated vascular aging by substantially, impairing vascular structure and function, as evidenced by the abnormal expression of aging factors, increased inflammation, reduced blood flow, pathological vessel dilation, and elevated collagen levels in a naturally aging mouse model. Moreover, RNA sequencing and molecular biology analyses revealed that the loss of SPNS2 in ECs increased cellular senescence biomarkers, aggravated the senescence-associated secretory phenotype (SASP), and inhibited cell proliferation. Mechanistically, silencing SPNS2 disrupts pyruvate metabolism homeostasis via pyruvate kinase M (PKM), resulting in mitochondrial dysfunction and EC senescence. Overall, SPNS2 expression and its functions in the mitochondria are crucial regulators of EC senescence and vascular aging. [ABSTRACT FROM AUTHOR]

Cytokine storm (CS) is linked with macrophage dysfunction and acute lung injury (ALI), which can lead to patient mortality. Glycolysis is preferentially exploited by the pro-inflammatory macrophages, in which pyruvate kinase M2 (PKM2) is a critical enzyme. The mechanism underlying the link between CS and ALI involves cell death, with the recently discovered programmed cell death known as ferroptosis being involved. However, the relationship between the glycolysis and ferroptosis in the context of CS-related ALI remains unclear. CS-associated ALI induced by poly I:C (10 mg/kg, i.v) and LPS (5 mg/kg, i.p) (IC: LPS) exhibit significant ferroptosis. Ferrostatin-1 (ferroptosis inhibitor) treatment attenuated IC:LPS‑induced mortality and lung injury. Moreover, Alveolar macrophage (AM) from IC:LPS model exhibited enhanced glycolysis and PKM2 translocation. The administration of ML-265(PKM2 monomer/dimer inhibitor) resulted in the formation of a highly active tetrameric PKM2, leading to improved survival and attenuation of ALI. Furthermore, ML-265 treatment decreased ferroptosis and restored the balance between anaerobic glycolysis and oxidative phosphorylation. Notably, in patients with lung infection, intracellular expression level of PKM2 were correlated with circulating inflammation. Enhanced ferroptosis and PKM2 nuclear translocation was noticed in CD14+ blood monocytes of lung infection patients with CS. In conclusion, PKM2 is a key regulatory node integrating metabolic reprograming with intra-nuclear function for the regulation of ferroptosis. Targeting PKM2 could be explored as a potential means in the future to prevent or alleviate hyper-inflammatory state or cytokines storm syndrome with aberrant ferroptotic cell death. [ABSTRACT FROM AUTHOR]

Prior studies have emphasized a bioenergetic crisis in the retinal pigment epithelium (RPE) as a critical factor in the development of age-related macular degeneration (AMD). The isoforms Fructose-1,6-bisphosphate aldolase C (ALDOC) and pyruvate kinase M2 (PKM2) have been proposed to play a role in AMD pathogenesis. While PKM2 and ALDOC are crucial for aerobic glycolysis in the neural retina, they are not as essential for the RPE. In this study, we examined the expression and activity of PKM2 and ALDOC in both young and aged RPE cells, as well as in the retina and RPE tissue of mice, including an experimentally induced AMD mouse model. Our findings reveal an upregulation in PKM2 and ALDOC expression, accompanied by increased pyruvate kinase activity, in the aged and AMD mouse RPE. Conversely, there is a decrease in ALDOC expression but an increase in PKM2 expression and pyruvate kinase activity in the aged and AMD retina. Overall, our study indicates that aged and AMD RPE cells tend to favor aerobic glycolysis, while this tendency is diminished in the aged and AMD retina. These results underscore the significance of targeting PKM2 and ALDOC in the RPE as a promising therapeutic approach to address the bioenergetic crisis and prevent vision loss in AMD. [ABSTRACT FROM AUTHOR]

Background: Alzheimer's disease (AD) is a complex neurodegenerative disorder, with recent research emphasizing the roles of microglia and their secreted extracellular vesicles in AD pathology. However, the involvement of specific molecular pathways contributing to neuronal death in the context of copper toxicity remains largely unexplored. Objective: This study investigates the interaction between pyruvate kinase M2 (PKM2) and dihydrolipoamide S‐acetyltransferase (DLAT), particularly focusing on copper‐induced neuronal death in Alzheimer's disease. Methods: Gene expression datasets were analyzed to identify key factors involved in AD‐related copper toxicity. The role of DLAT was validated using 5xFAD transgenic mice, while in vitro experiments were conducted to assess the impact of microglial exosomes on neuronal PKM2 transfer and DLAT expression. The effects of inhibiting the PKM2 transfer via microglial exosomes on DLAT expression and copper‐induced neuronal death were also evaluated. Results: DLAT was identified as a critical factor in the pathology of AD, particularly in copper toxicity. In 5xFAD mice, increased DLAT expression was linked to hippocampal damage and cognitive decline. In vitro, microglial exosomes were shown to facilitate the transfer of PKM2 to neurons, leading to upregulation of DLAT expression and increased copper‐induced neuronal death. Inhibition of PKM2 transfer via exosomes resulted in a significant reduction in DLAT expression, mitigating neuronal death and slowing AD progression. Conclusion: This study uncovers a novel pathway involving microglial exosomes and the PKM2‐DLAT interaction in copper‐induced neuronal death, providing potential therapeutic targets for Alzheimer's disease. Blocking PKM2 transfer could offer new strategies for reducing neuronal damage and slowing disease progression in AD. [ABSTRACT FROM AUTHOR]

Introduction: The presence of hypoxic‐ischemic brain damage (HIBD) in neonates triggers a strong neuroinflammatory reaction. Pyroptosis, a programmed cell death mechanism associated with inflammation, plays a crucial role in HIBD. Pyruvate kinase M2 (PKM2) plays a significant role in connecting metabolic processes and inflammatory responses, but whether it affects hippocampus pyroptosis in HIBD is unclear. The aim of this study is to elucidate the role of PKM2 in HIBD and to propose a novel therapeutic approach for neonatal ischemic‐hypoxic encephalopathy. Methods: In this study, we employed neonatal 7‐day‐old Sprague Dawley rats to establish a model of HIBD using the Rice–Vannucci surgical technique and a hypoxia device. To inhibit the elevation of PKM2, we utilized the PKM2 inhibitor shikonin. The rats were categorized into four groups: Sham, Shikonin, HIBD, and Shikonin + HIBD. Behavioral tests, hematoxylin eosin staining, immunofluorescence staining, ELISA (IL‐1β, IL‐18), and LDH were conducted in each group to evaluate neurological function, hippocampal damage, the occurrence of neuronal pyroptosis, and the neuroinflammation. Western blot was used to assess the expression levels of PKM2, NLRP3, Caspase‐1, Cleaved Caspase‐1, GSDMD, GSDMDN, and IL‐1β. Results: The expression of PKM2 elevated in hippocampal tissues of the HIBD model and the localization of PKM2 in the hippocampus was activated in neurons instead of microglia during the HIBD. Meanwhile, the inhibition of PKM2 improved the behavioral test scores and the body weight of rats, the neuronal damage in the CA1 region of hippocampal tissue was also attenuated. In addition, inhibiting PKM2 alleviated neuronal pyroptosis by decreasing the expression of PKM2, NLRP3, Caspase‐1, Cleaved Caspase‐1, GSDMD, GSDMDN. Furthermore, serum levels of LDH and inflammatory factors IL‐1β and IL‐18 decrease with PKM2 inhibition. Conclusions: Based on these findings, we can conclude that PKM2 plays a crucial role in regulating hippocampal neuronal pyroptosis of HIBD rats via NLRP3/Caspase‐1/GSDMD pathway. Therefore, inhibiting PKM2 could be a promising therapeutic strategy for the treatment of neonatal ischemic‐hypoxic encephalopathy. [ABSTRACT FROM AUTHOR]

Hepatocellular carcinoma (HCC) is one of the deadly malignant tumors that directly leads to the death of nearly one million people worldwide every year, causing a serious burden on society. In the presence of sufficient oxygen, HCC cells rapidly generate energy through aerobic glycolysis, which promotes tumor cell proliferation, immune evasion, metastasis, angiogenesis, and drug resistance. Pyruvate kinase M2 (PKM2) is a key rate‐limiting enzyme in glycolysis. In recent years, studies have found that PKM2 not only exerts pyruvate kinase activity in the process of glucose metabolism, but also exerts protein kinase activity in non‐metabolic pathways to affect tumor cell processes, and its activity is flexibly regulated by various posttranslational modifications such as acetylation, phosphorylation, lactylation, ubiquitination, SUMOylation, and so forth. This review summarizes the role of posttranslational modifications of PKM2‐related sites in the development of HCC. Summary: Hepatocellular carcinoma (HCC) is one of the deadly malignant tumors.Even in the case of sufficient oxygen, HCC cells rapidly generate energy through aerobic glycolysis.Pyruvate kinase M2 (PKM2) is a key rate‐limiting enzyme in glycolysis.Recent studies have found that the posttranslational modification of PKM2 flexibly regulates its pyruvate kinase activity and protein kinase activity, thus affecting the important physiological functions of cells.This review summarizes the role of posttranslational modifications of PKM2‐related sites in the development of HCC.It has been found that posttranslational modifications of PKM2‐related sites mostly promote the occurrence, metastasis and drug resistance of HCC, often suggesting poor prognosis. [ABSTRACT FROM AUTHOR]

Mycoplasma bovis is a global problem for the cattle industry due to its high infection rates and associated morbidity, although its pathophysiology is poorly understood. In this study, the M. bovis transcriptome and proteome were analyzed to further investigate the biology of clinical isolates of M. bovis. A differential analysis of M. bovis, a clinical isolate (NX114), and an international type strain (PG45) at the logarithmic stage of growth, was carried out using prokaryotic transcriptome and 4D-label-free quantitative non-labeled proteomics. Transcriptomics and proteomics identified 193 DEGs and 158 DEPs, respectively, with significant differences in 49 proteins/34 transcriptomic CDS post-translational protein sequences (15 jointly up-regulated and 21 jointly down-regulated). GO comments indicate membrane, cytoplasmic and ribosome proteins were important components of the total proteins of M. bovis NX114 clinical isolate. KEGG enrichment revealed that M. bovis NX114 is mainly associated with energy metabolism, the biosynthesis of secondary metabolites, and the ABC transporters system. In addition, we annotated a novel adhesion protein that may be closely related to M. bovis infection. Triosephosphate isomerase (TpiA) and Pyruvate kinase (Pyk) genes may be the key enzymes that regulate the growth and maintenance of M. bovis and are involved in the pathogenic process as virulence factors. The results of the study revealed the biology of different isolates of M. bovis and may provide research ideas for the pathogenic mechanism of M. bovis. [ABSTRACT FROM AUTHOR]

Recent studies have shown that high dietary fructose intake enhances intestinal tumor growth in mice. Our previous work indicated that glucose enables hypoxic colorectal cancer (CRC) cells to resist receptor-interacting protein (RIP)-dependent necroptosis. Despite having the same chemical formula, glucose and fructose are absorbed through different transporters yet both can enter the glycolytic metabolic pathway. The excessive intake of dietary fructose, leading to its overflow into the colon, allows colonic cells to absorb fructose apically. This study explores the mechanisms behind apical fructose-mediated death resistance in CRC cells under hypoxic stress. Utilizing three CRC cell lines (Caco-2, HT29, and T84) under normoxic and hypoxic conditions with varying fructose concentrations, we assessed lactate dehydrogenase (LDH) activity, RIP1/3 complex formation (a necroptosis marker), and cell integrity. We investigated the role of fructose in glycolytic-mediated death resistance using glycolytic inhibitors iodoacetate (IA, a glycolytic inhibitor to glyceraldehyde 3-phosphate dehydrogenase), and UK5099 (UK, an inhibitor to mitochondrial pyruvate carrier). Our findings reveal that apical fructose prevents the hypoxia-induced RIP-dependent necroptosis in Caco-2 and HT29 cells. Fructose exposure under hypoxia also preserved epithelial integrity. IA, but not UK, blocked fructose-mediated glycolytic metabolite production and necrosis, indicating that anaerobic glycolytic metabolites facilitate death resistance. Notably, fructose treatment upregulated pyruvate kinase (PK)-M1 mRNA in hypoxic Caco-2 and HT29 cells, while PKM2 upregulation was exclusive to HT29 cells. In conclusion, apical fructose utilization through glycolysis effectively inhibits hypoxia-induced RIP-dependent necroptosis in CRC cells, shedding light on potential metabolic adaptation mechanisms in the tumor microenvironment and suggesting novel targets for therapeutic intervention. [ABSTRACT FROM AUTHOR]

Cancer is a global health challenge, despite significant advancements in research. Addressing this issue, we report the design, synthesis and biological evaluation of pyrimidinyl indoles as potential antineoplastic agents. Pyrimidinyl indoles interact with pyruvate kinase isoform M2 (PKM2), which is commonly overexpressed in oral, lung, breast and colorectal cancers. In silico studies indicated that these molecules are having affinity towards PKM2 and targeting key residues such as Phe26, Leu27, Tyr390, Gln393, Leu394 and Glu397 at the interfacial active site region between the two chains of PKM2. Thereafter compounds were designed, synthesized and characterized using nuclear magnetic resonance (NMR), infrared spectroscopy (IR) and mass spectrometry (MS). This was followed by in vitro screening using cell lines and enzyme‐coupled assays. One of the designed PKM2 inhibitor demonstrated potent anticancer activity against MCF‐7 (Breast Cancer) cells while sparing normal MCF‐10 A breast cells. Molecular dynamics (MD) simulation studies showed that the developed inhibitor stabilized the PKM2 active site over a 100 ns simulation. [ABSTRACT FROM AUTHOR]

Objective: To study the relationship between serum lysyl oxidase like-2 protein (LOXL2) and pyruvate kinase M2 (PKM2) and long-term recurrence after radical resection in patients with cervical cancer. Methods: 302 patients with cervical cancer who underwent radical surgery in Qilu Hospital of Shandong University Dezhou Hospital from January 2017 to March 2018 were selected as observation subjects, the patients were followed up for 5 years, and 3 cases were lost to follow-up. The patients were divided into recurrence group (72 cases) and non-recurrence group (230 cases) according to whether the patients had long-term recurrence. The levels of serum LOXL2 and PKM2 were compared between recurrence group and non-recurrence group. The influencing factors of long-term recurrence after radical resection were analyzed by multivariate Logistic regression analysis, the predictive value of serum LOXL2 combined with PKM2 for long-term recurrence after radical resection were analyzed by receiver operating characteristic (ROC) curve. Results: There were 72 cases of recurrence in 302 patients 5 years after operation, and the recurrence rate was 23.84% (72/302). The serum levels of LOXL2 and PKM2 in recurrence group were higher than those in non-recurrence group (P<0.05). Multivariate Logistic regression analysis showed that, the surgical mode was laparoscopic surgery, infiltration depth≥ 1/2 muscular layer, lymph node metastasis, elevated LOXL2 and elevated PKM2 were risk factors for long-term recurrence after operation (P<0.05). ROC curve analysis showed that, serum LOXL2 combined with PKM2 had the highest predictive value for long-term recurrence in patients after radical resection, the area under curve (AUC) was 0.921, and the sensitivity was 95.24%. Conclusion: The levels of serum LOXL2 and PKM2 in patients with cervical cancer are increase, and they are risk factors for long-term recurrence after radical resection. Serum LOXL2 combine with PKM2 has a high predictive value for long-term recurrence in patients after surgery. [ABSTRACT FROM AUTHOR]

Simple Summary: When faced with starvation, fish can consume energy reserves and adaptively modify the metabolic responses of main energy substrates for fundamental activity. Carbohydrates and lipids are mobilized preferentially in most fish under starvation. However, the mobilization of endogenous energy in starving fish varies with the species, tissue, and fasting duration. Liver tissue is the primary tissue for energy reserves in multiple fish, particularly lipid-associated components. Therefore, this study was conducted to investigate the phenotypic changes in physiological, metabolic, histological, and molecular characteristics of glucose and lipid metabolism in the liver of Synechogobius hasta experiencing different starvation periods. Hepatic glycogen and triglycerides were concurrently mobilized in S. hasta during starvation, which was accompanied by consistent changes in liver intermediary metabolism enzyme activities and an increase in liver antioxidant capacity to some extent. S. hasta livers exhibited evident vacuolations, larger intercellular spaces, and other microstructural abnormalities from the third day of starvation. Additionally, fasting not only transcriptionally attenuated glucose and lipid anabolism, but also enhanced the catabolic pathway and fatty acid transport in S. hasta liver. These findings may provide preliminary data for further assessing the energy strategy to cope with starvation and the underlying mechanism in S. hasta and other fish species. In this study, the influence of fasting on hepatic glucose and lipid metabolism was explored by examining biochemical, antioxidative, and morphological indicators and transcriptional expression in the liver of javelin goby (Synechogobius hasta) after 0, 3, 7, or 14 days of starvation. Marked reductions in hepatic glycogen and triglycerides occurred from the seventh day of starvation until the end of the trial (p < 0.05). However, no alterations in hepatic cholesterol or protein were detected throughout the entire experiment (p > 0.05). During fasting, the activities of pyruvate kinase, lactate dehydrogenase, and glycogen phosphorylase a all rose firstly and then fell (p < 0.05). The activities of hepatic fatty acid synthase and acetyl-CoA carboxylase were minimized to their lowest levels at the end of food deprivation (p < 0.05), while lipase was elevated after 7–14 days of fasting (p < 0.05). Catalase, glutathione, and the total antioxidative capacity were increased and maintained their higher values in the later stage of fasting (p < 0.05), whereas malondialdehyde was not significantly changed (p > 0.05). Hepatic vein congestion, remarkable cytoplasmic vacuoles, and irregular cell shape were present in S. hasta which endured 3–7 days of fasting and were less pronounced when food shortage was prolonged. In terms of genes associated with glucose and lipid metabolism, the hepatic phosphofructokinase gene was constantly up-regulated during fasting (p < 0.05). However, the mRNA levels of glycogen synthase and glucose-6-phosphatase were obviously lower when the food scarcity extended to 7 days or more (p < 0.05). Fatty acid synthase, stearoyl-CoA desaturase 1, and peroxisome proliferator-activated receptor γ were substantially down-regulated in S. hasta livers after 7–14 days of food deprivation (p < 0.05). However, genes involved in lipolysis and fatty acid transport were transcriptionally enhanced to varying extents and peaked at the end of fasting (p < 0.05). Overall, starvation lasting 7 days or more could concurrently mobilize hepatic carbohydrates and fat as energy resources and diminished their hepatic accumulation by suppressing biosynthesis and enhancing catabolism and transport, ultimately metabolically and structurally perturbing the liver in S. hasta. This work presents preliminary data on the dynamic characteristics of hepatic glucose and lipid metabolism in S. hasta in response to starvation, which may shed light on the sophisticated mechanisms of energetic homeostasis in fish facing nutrient unavailability and may benefit the utilization/conservation of S. hasta. [ABSTRACT FROM AUTHOR]

Cipangopaludina chinensis is a common freshwater mollusk that is widely distributed worldwide, especially in China. In our research, 1,382 proteins and 1,039 phosphorylated proteins were identified from C. chinensis carcasses, and 690 differentially expressed proteins (DEPs) were quantified. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed that the DEPs are involved in cellular processes, single-organism processes, metabolic processes, developmental processes, localization, and biological regulation. The phosphorylated proteins were found to be related to the Rap1 signaling pathway, Ras signaling pathway, calcium signaling pathway, and longevity-regulating pathways. Moreover, we also identified important regulatory enzymes, such as guanylate cyclase, tyrosine protein kinase, receptor protein tyrosine kinase, and glyoxylate reductase/hydroxypyruvate reductase. Notably, we found guanylate cyclase to be present in multiple signaling pathways, including the Rap1 signaling pathway, calcium signaling pathway, Ras signaling pathway, insulin secretion, longevity regulating pathway, glutamatergic synapse, circadian entrainment, and gap junction. This enzyme may play a crucial role in regulating molecular mechanisms in C. chinensis. In summary, proteomic and phosphoproteomic analyses of C. chinensis carcasses displayed significant differences among different geographical isolates, which helps enhance our understanding of food nutrition, signaling pathways, and metabolic mechanisms in C. chinensis. [ABSTRACT FROM AUTHOR]

Background: At present, hepatic ischemia-reperfusion injury (IRI) is an important complication of partial hepatectomy and liver transplantation, and it is an important cause of poor prognosis. Spleen tyrosine kinase(SYK) plays an important role in a variety of signaling pathways in the liver, but its role in hepatic IRI is still unclear. This study aims to investigate the role and mechanism of SYK in hepatic IRI and tumor recurrence. Methods: We first observed the activation of SYK in the liver of mice in response to hepatic IRI. Subsequently, Pharmacological inhibitions of SYK were used to evaluated the effect of SYK on neutrophil recruitment and NETosis, and further explored the effect of SYK on IRI and tumor recurrence. Results: Our study shows that SYK is activated in response to hepatic IRI and aggravates liver injury. On the one hand, neutrophils SYK during the early stage of liver reperfusion increases neutrophil extracellular traps (NETs) production by promoting Pyruvate kinase M2(PKM2) nuclear translocation leading to upregulation of phosphorylated STAT3, thereby exacerbating liver inflammation and tumor recurrence. On the other hand, macrophages SYK can promote the recruitment of neutrophils and increase the activation of NLRP3 inflammasome and IL1β, which further promotes the formation of NETs. Conclusions: Our study demonstrates that neutrophil and macrophage SYK synergistically promote hepatic IRI and tumor recurrence, and SYK may be a potential target to improve postoperative hepatic IRI and tumor recurrence. [ABSTRACT FROM AUTHOR]

Background: Pyruvate kinase (PK) deficiency is an inherited red blood cell (RBC) enzyme disorder that results in non-immune chronic hemolytic anemia. Characteristic symptoms of PK deficiency include anemia, fatigue, splenomegaly, jaundice, gallstones, thrombosis, and transfusional iron overload. Previously, treatments aimed at symptomatic management with RBC transfusions, phototherapy, folic acid supplementation, splenectomy, and iron chelation therapy when iron overload was documented. Mitapivat, a recently approved medication for treatment of PK-deficiency hemolytic anemia, is an oral allosteric activator of wild-type and mutant RBC PK enzymes. In this paper, we describe three cases of PK-deficiency anemia treated with mitapivat and describe modern management of this rare hemolytic disorder. Methods: A retrospective healthcare database analysis was conducted to extract relevant information. Both quantitative and qualitative methods were integrated to provide a more comprehensive understanding of the cases. Results: Two patients responded well to treatment with mitapivat, noted by an increase in hemoglobin levels, improvements in hemolytic markers, less frequent or no RBC transfusion requirements, and improvements in fatigue. One patient carrying two non-missense mutations of the PKLR gene did not respond to treatment with mitapivat. As variations in patient-specific factors (including genotype) can lead to different clinical manifestations and responses to treatment, we recommend considering both the phenotype (clinical symptoms and signs) and the genotype of the PKLR gene when making therapeutic decisions about starting a patient on mitapivat. Conclusions: While mitapivat addresses the previously unmet needs of most patients with PK deficiency as the first and only disease-modifying medication to receive approval for this condition, not all patients with PK deficiency are amenable to treatment with mitapivat. [ABSTRACT FROM AUTHOR]

Cardiac metabolism ensures a continuous ATP supply, primarily using fatty acids in a healthy state and favoring glucose in pathological conditions. Pyruvate kinase muscle (PKM) controls the final step of glycolysis, with PKM1 being the main isoform in the heart. PKM2, elevated in various heart diseases, has been suggested to play a protective role in cardiac stress, but its function in basal cardiac metabolism remains unclear. We examined hearts from global PKM2 knockout (PKM2−/−) mice and found reduced intracellular glucose. Isotopic tracing of U‐13C glucose revealed a shift to biosynthetic pathways in PKM2−/− cardiomyocytes. Total ATP content was two‐thirds lower in PKM2−/− hearts, and functional analysis indicated reduced mitochondrial oxygen consumption. Total reactive oxygen species (ROS) and mitochondrial superoxide were also increased in PKM2−/− cardiomyocytes. Intriguingly, PKM2−/− hearts had preserved ejection fraction compared to controls. Mechanistically, increased calcium/calmodulin‐dependent kinase II activity and phospholamban phosphorylation may contribute to higher sarcoendoplasmic reticulum calcium ATPase 2 pump activity in PKM2−/− hearts. Loss of PKM2 led to altered glucose metabolism, diminished mitochondrial function, and increased ROS in cardiomyocytes. These data suggest that cardiac PKM2 acts as an important rheostat to maintain ATP levels while limiting oxidative stress. Although loss of PKM2 did not impair baseline contractility, its absence may make hearts more sensitive to environmental stress or injury. [ABSTRACT FROM AUTHOR]

Though Ginsenoside F2 (GF2), a protopanaxadiol saponin from Panax ginseng, is known to have an anticancer effect, its underlying mechanism still remains unclear. In our model, the anti-glycolytic mechanism of GF2 was investigated in human cervical cancer cells in association with miR193a-5p and the β-catenin/c-Myc/Hexokinase 2 (HK2) signaling axis. Here, GF2 exerted significant cytotoxicity and antiproliferation activity, increased sub-G1, and attenuated the expression of pro-Poly (ADPribose) polymerase (pro-PARP) and pro-cysteine aspartyl-specific protease (procaspase3) in HeLa and SiHa cells. Consistently, GF2 attenuated the expression of Wnt, β-catenin, and c-Myc and their downstream target genes such as HK2, pyruvate kinase isozymes M2 (PKM2), and lactate dehydrogenase A (LDHA), along with a decreased production of glucose and lactate in HeLa and SiHa cells. Moreover, GF2 suppressed β-catenin and c-Myc stability in the presence and absence of cycloheximide in HeLa cells, respectively. Additionally, the depletion of β-catenin reduced the expression of c-Myc and HK2 in HeLa cells, while pyruvate treatment reversed the ability of GF2 to inhibit β-catenin, c-Myc, and PKM2 in GF2-treated HeLa cells. Notably, GF2 upregulated the expression of microRNA139a-5p (miR139a-5p) in HeLa cells. Consistently, the miR139a-5p mimic enhanced the suppression of β-catenin, c-Myc, and HK2, while the miR193a-5p inhibitor reversed the ability of GF2 to attenuate the expression of β-catenin, c-Myc, and HK2 in HeLa cells. Overall, these findings suggest that GF2 induces apoptosis via the activation of miR193a-5p and the inhibition of β-catenin/c-Myc/HK signaling in cervical cancer cells. [ABSTRACT FROM AUTHOR]

Background and Objectives: To evaluate the clinical findings of glucose 6-phosphate dehydrogenase (G6PD) and pyruvate kinase (PK) deficiency in prolonged jaundice and to determine whether the systemic immune inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) can be used in the diagnosis of neonatal prolonged jaundice. Materials and Methods: Among full-term neonates with hyperbilirubinemia who were admitted to Medicine Hospital between January 2019 and January 2024 with the complaint of jaundice, 167 infants with a serum bilirubin level above 10 mg/dL, whose jaundice persisted after the 10th day, were included in this study. Results: G6PD activity was negatively correlated with NLR, SII, age, and hematocrit (Hct). There was a weak negative correlation between G6PD and NLR and a moderate negative correlation between G6PD activity and SII when adjusted for age and Hct. PK activity showed no significant correlation with G6PD, NLR, PLR, SII, age, and Hct. A linear relationship was observed between G6PD activity and SII and NLR. Conclusions: NLR and SII can be easily calculated in the evaluation of prolonged jaundice in G6PD deficiency has a considerable advantage. NLR and SII levels may contribute by preventing further tests for prolonged jaundice and regulating its treatment. It may be useful to form an opinion in emergencies and in early diagnostic period. [ABSTRACT FROM AUTHOR]

BackgroundResistance to existing therapies is a significant challenge in improving outcomes for glioblastoma (GBM) patients. Metabolic plasticity has emerged as an important contributor to therapy resistance, including radiation therapy (RT). Here, we investigated how GBM cells reprogram their glucose metabolism in response to RT to promote radiation resistance.MethodsEffects of radiation on glucose metabolism of human GBM specimens were examined in vitro and in vivo with the use of metabolic and enzymatic assays, targeted metabolomics, and FDG-PET. Radiosensitization potential of interfering with M2 isoform of pyruvate kinase (PKM2) activity was tested via gliomasphere formation assays and in vivo human GBM models.ResultsHere, we show that RT induces increased glucose utilization by GBM cells, and this is accompanied with translocation of GLUT3 transporters to the cell membrane. Irradiated GBM cells route glucose carbons through the pentose phosphate pathway (PPP) to harness the antioxidant power of the PPP and support survival after radiation. This response is regulated in part by the PKM2. Activators of PKM2 can antagonize the radiation-induced rewiring of glucose metabolism and radiosensitize GBM cells in vitro and in vivo.ConclusionsThese findings open the possibility that interventions designed to target cancer-specific regulators of metabolic plasticity, such as PKM2, rather than specific metabolic pathways, have the potential to improve the radiotherapeutic outcomes in GBM patients.

L-Fuculokinases play a key role in both natural and synthetic metabolic pathways, not only for the utilization of L-fucose, but also for related monosaccharides, and catalyze selective phosphorylation of L-fuculose in the 1-position or of D-ribulose in the 5-position. Therefore, L-fuculokinases have been selected, the fucK gene from Escherichia coli K12 has been synthesized and cloned into an appropriate expression vector for the transformation of E. coli BL21(DE3). The cultivation of the transformed strain and the overexpression of the fucK gene has led to highly active L-fuculokinase after straightforward downstream processing. The soluble fraction from the crude cell extract could be directly applied in the enzymatic phosphorylation of L-fuculose. Recycling of the ATP cofactor was done with pyruvate kinase (PK) and the high energy phosphoenolpyruvate (PEP) as donor. The time course of the phosphorylation reactions has been monitored by 31P-NMR and 1H-NMR spectroscopy and L-fuculose could be phosphorylated with nearly 100% conversion. After standard workup, the L-fuculose-1-phosphate has been obtained in high yield and purity. [ABSTRACT FROM AUTHOR]

Growing evidence suggests that metabolic regulation directly influences cellular function and development and thus may be more dynamic than previously expected. In vivo and in real-time analysis of metabolite activities during development is crucial to test this idea directly. In this study, we employ two metabolic biosensors to track the dynamics of pyruvate and oxidative phosphorylation (Oxphos) during the early embryogenesis of the sea urchin. A pyruvate sensor, PyronicSF, shows the signal enrichment on the mitotic apparatus, which is consistent with the localization patterns of the corresponding enzyme, pyruvate kinase (PKM). The addition of pyruvate increases the PyronicSF signal, while PKM knockdown decreases its signal, responding to the pyruvate level in the cell. Similarly, a ratio-metric sensor, Grx-roGFP, that reads the redox potential of the cell responds to DTT and H 2 O 2 , the known reducer and inducer of Oxphos. These observations suggest that these metabolic biosensors faithfully reflect the metabolic status in the cell during embryogenesis. The time-lapse imaging of these biosensors suggests that pyruvate and Oxphos levels change both spatially and temporarily during embryonic development. Pyruvate level is increased first in micromeres compared to other blastomeres at the 16-cell stage and remains high in ectoderm while decreasing in endomesoderm during gastrulation. In contrast, the Oxphos signal first decreases in micromeres at the 16-cell stage, while it increases in the endomesoderm during gastrulation, showing the opposite trend of the pyruvate signal. These results suggest that metabolic regulation is indeed both temporally and spatially dynamic during embryogenesis, and these biosensors are a valuable tool to monitor metabolic activities in real-time in developing embryos. • PKM and pyruvate localize on the spindle and in the nucleus during early embryogenesis of the sea urchin. • Pyruvate is increased in micromeres, while Oxidative phosphorylation is decreased in micromeres. • Pyruvate and Oxidative phosphorylation sensors show an opposite trend of expression dynamics during embryogenesis. • Metabolic biosensors are valuable tools for analyzing in vivo metabolic regulation in developing embryos. [ABSTRACT FROM AUTHOR]

The postmortem conversion of muscle to meat goes through a series of complex physiological and biochemical changes, among which protein post-translational modifications (PTMs) are key factors affecting meat quality. Glycolysis is the major energy supply pathway in postmortem muscle. PTMs can change the function and structure of pyruvate kinase, a rate-limiting enzyme in the glycolytic pathway, which can in turn affect meat quality. Beginning with an overview of the structure and function of pyruvate kinase, this article reviews the recent research progress on the effects of PTMs of pyruvate kinase on its function and structure and the effects of pyruvate kinase phosphorylation, acetylation and S-nitrosylation on meat quality.

Fumonisin B1 (FB1), a mycotoxin produced by Fusarium species, is prevalent in crops and animal feed, posing significant health risks to livestock and humans. FB1 induces oxidative stress in Sertoli cells, destroys testicular structure, and affects spermatogenesis. However, methods to mitigate the reproductive toxicity of FB1 in testes remain unknown. Quercetin, a natural flavonoid antioxidant, may offer protective benefits. This study investigated the protective effects and mechanisms of quercetin against FB1-induced reproductive toxicity in TM4 cells (a Sertoli cell line). The results indicated that 40 μM quercetin improved cell viability, reduced apoptosis, and preserved cell functions. Quercetin also decreased reactive oxygen species (ROS) levels in TM4 cells exposed to FB1, enhanced the expression of antioxidant genes, and improved mitochondrial membrane potential. Compared with FB1 alone, the combination of quercetin and FB1 increased ATP levels, as well as pyruvate and lactic acid, the key glycolysis products. Furthermore, this combination elevated the mRNA and protein expression of glycolysis-related genes, including glucose-6-phosphate isomerase 1 (Gpi1), hexokinase 2 (Hk2), aldolase (Aldoa), pyruvate kinase, muscle (Pkm), lactate dehydrogenase A (Ldha) and phosphofructokinase, liver, B-type (Pfkl). Quercetin also boosted the activity of PKM and LDHA, two crucial glycolytic enzymes. In summary, quercetin mitigates FB1-induced toxicity in TM4 cells by reducing ROS levels and enhancing glycolysis. This study offers new insights into preventing and treating FB1-induced toxic damage to the male reproductive system and highlights the potential application of quercetin. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The immune system requires a high energy expenditure to resist pathogen invasion. Macrophages undergo metabolic reprogramming to meet these energy requirements and immunologic activity and polarize to M1-type macrophages. Understanding the metabolic pathway switching in large yellow croaker (Larimichthys crocea) macrophages in response to lipopolysaccharide (LPS) stimulation and whether this switching affects immunity is helpful in explaining the stronger immunity of hypoxia-tolerant L. crocea. In this study, transcript levels of glycolytic pathway genes (Glut1 and Pdk1), mRNA levels or enzyme activities of glycolytic enzymes [hexokinase (HK), phosphofructokinase (PFK), pyruvate kinase (PK), and lactate dehydrogenase A (LDHA)], aerobic respiratory enzymes [pyruvate dehydrogenase (PDH), isocitrate dehydrogenase (IDH), and succinate dehydrogenase (SDH)], metabolites [lactic acid (LA) and adenosine triphosphate (ATP)], levels of bactericidal products [reactive oxygen species (ROS) and nitric oxide (NO)], and transcripts and level changes of inflammatory factors [IL1β, TNFα, and interferon (IFN) γ] were detected in LPSstimulated L. crocea head kidney macrophages. We showed that glycolysis was significantly induced, the tricarboxylic acid (TCA) cycle was inhibited, and metabolic reprogramming occurred, showing the Warburg effect when immune cells were activated. To determine the potential regulatory mechanism behind these changes, LcHIF-1α was detected and found to be significantly induced and transferred to the nucleus after LPS stimulation. LcHif-1a interference led to a significant reduction in glycolytic pathway gene transcript expression, enzyme activity, metabolites, bactericidal substances, and inflammatory factor levels; a significant increase in the aerobic respiration enzymes; and decreased migration, invasion, and phagocytosis. Further ultrastructural observation by electron microscopy showed that fewer microspheres contained phagocytes and that more cells were damaged after LcHif-1α interference. LcHif-1α overexpression L. crocea head kidney macrophages showed the opposite trend, and promoter activities of Ldha and Il1β were significantly enhanced after LcHif-1α overexpression in HEK293T cells. Our data showed that LcHIF-1α acted as a metabolic switch in L. crocea macrophages and was important in polarization. Hypoxia-tolerant L. crocea head kidney showed a stronger Warburg effect and inhibited the TCA cycle, higher metabolites, and bactericidal substance levels. These results collectively revealed that LcHif-1α may promote the functional activities of head kidney macrophages in protecting hypoxia-tolerant L. crocea from Aeromonas hydrophila infection. [ABSTRACT FROM AUTHOR]

Aims Carbon source is a necessary nutrient for bacterial strain growth. In industrial production, the cost of using different carbon sources varies greatly. Moreover, the complex environment in space may cause metabolic a series of changes in the strain, and this method has been successfully applied in some basic research. To date, space mutagenesis is still limited number of studies, particularly in carbon metabolism of probiotics. Methods and results HG-R7970-41 was isolated from bacterium suspension (Probio-M9) after space flight, which can produce capsular polysaccharide after space mutagenesis. Phenotype Microarray (PM) was used to evaluated the metabolism of HG-R7970-41 in 190 single carbon sources. RNA sequencing and total protein identification of two strains revealed their different carbon metabolism mechanisms. PM results demonstrated the metabolism of 10 carbon sources were different between Probio-M9 and HG-R7970-41. Transcriptomic and proteomic analyses revealed that this change in carbon metabolism of HG-R7970-41 mainly related to changes in phosphorylation and the glycolysis pathway. Based on the metabolic mechanism of different carbon sources and related gene cluster analysis, we found that the final metabolic activities of HG-R7970-41 and Probio-M9 were mainly regulated by PTS-specific membrane embedded permease, carbohydrate kinase and two rate-limiting enzymes (phosphofructokinase and pyruvate kinase) in the glycolysis pathway. The expanded culture test also confirmed that HG-R7970-41 had different metabolic characteristics from original strain. Conclusions These results suggested that space environment could change carbon metabolism of Probio-M9. The new isolate (HG-R7970-41) showed a different carbon metabolism pattern from the original strain mainly by the regulation of two rate-limiting enzymes. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to identify candidate genes that play important roles in skeletal muscle development in ducks. Methods: In this study, we investigated the transcriptional sequencing of embryonic pectoral muscles from two specialized lines: Liancheng white ducks (female) and Cherry valley ducks (male) hybrid Line A (LCA) and Line C (LCC) ducks. In addition, prediction of target genes for the differentially expressed mRNAs was conducted and the enriched gene ontology (GO) terms and Kyoto encyclopedia of genes and genomes signaling pathways were further analyzed. Finally, a protein-to-protein interaction network was analyzed by using the target genes to gain insights into their potential functional association. Results: A total of 1,428 differentially expressed genes (DEGs) with 762 being up-regulated genes and 666 being down-regulated genes in pectoral muscle of LCA and LCC ducks identified by RNA-seq (p<0.05). Meanwhile, 23 GO terms in the down-regulated genes and 75 GO terms in up-regulated genes were significantly enriched (p<0.05). Furthermore, the top 5 most enriched pathways were ECM-receptor interaction, fatty acid degradation, pyruvate degradation, PPAR signaling pathway, and glycolysis/gluconeogenesis. Finally, the candidate genes including integrin b3 (Itgb3), pyruvate kinase M1/2 (Pkm), insulin-like growth factor 1 (Igf1), glucose-6-phosphate isomerase (Gpi), GABA type A receptor-associated protein-like 1 (Gabarapl1), and thyroid hormone receptor beta (Thrb) showed the most expression difference, and then were selected to verification by quantitative real-time polymerase chain reaction (qRT-PCR). The result of qRT-PCR was consistent with that of transcriptome sequencing. Conclusion: This study provided information of molecular mechanisms underlying the developmental differences in skeletal muscles between specialized duck lines. [ABSTRACT FROM AUTHOR]

The effect of hypoxia on the level of expression of pyruvate kinase (PKM), octopine dehydrogenase (OcDH), and malate dehydrogenase (MDH) genes in the gill tissue of the Mediterranean mussel Mytilus galloprovincialis (L., 1819) was studied experimentally. The control group of mollusks was kept at 9–10°C, and the oxygen level in the water was 8.5 mg O2 L–1. The experimental levels were at 9–10°C and 2.2 mg O2 L–1. The exposure was 24 and 72 h. Some of the individuals were subsequently subjected to the reoxygenation procedure. Under conditions of hypoxia, the expression level of OcDH and MDH genes increased by three and two times, respectively (p < 0.05). At the same time, OcDH expression showed sensitivity to the oxygen content in the medium. Under the conditions of reoxygenation, the process was completely suppressed. The expression of the PKM gene, on the contrary, did not depend on hypoxic effects and remained at the level of the control values. [ABSTRACT FROM AUTHOR]

Summary: Pyruvate kinase (PK) deficiency, a rare, congenital haemolytic anaemia caused by mutations in the PKLR gene, is associated with many clinical manifestations, but the full disease burden has yet to be characterised. The Peak Registry (NCT03481738) is an observational, longitudinal registry of adult and paediatric patients with PK deficiency. Here, we described comorbidities and complications in these patients by age at most recent visit and PKLR genotype. As of 13 May 2022, 241 patients were included in the analysis. In total, 48.3% had undergone splenectomy and 50.5% had received chelation therapy. History of iron overload (before enrolment/during follow‐up) was common (52.5%), even in never‐transfused patients (20.7%). Neonatal complications and symptoms included jaundice, splenomegaly and hepatomegaly, with treatment interventions required in 41.5%. Among adults, osteopenia/osteoporosis occurred in 19.0% and pulmonary hypertension in 6.7%, with median onset ages of 37, 33 and 22 years, respectively. Biliary events and bone health problems were common across PKLR genotypes. Among 11 patients who had thromboembolic events, eight had undergone prior splenectomy. Patients with PK deficiency may have many complications, which can occur early in and throughout life. Awareness of their high disease burden may help clinicians better provide appropriate monitoring and management of these patients. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chinese Institute of Food Science & Technology / Zhongguo Shipin Xuebao is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

It is well established that pyruvate kinase M2 (PKM2) activity contributes to metabolic reprogramming in various cancers, including colorectal cancer (CRC). Estrogen or 17β‐estradiol (E2) signaling is also known to modulate glycolysis markers in cancer cells. However, whether the inhibition of PKM2 combined with E2 treatment could adversely affect glucose metabolism in CRC cells remains to be investigated. First, we confirmed the metabolic plasticity of CRC cells under varying environmental conditions. Next, we identified glycolysis markers that were upregulated in CRC patients and assessed in vitro mRNA levels following E2 treatment. We found that PKM2 expression, which is highly upregulated in CRC clinical samples, is not altered by E2 treatment in CRC cells. In this study, glucose uptake, generation of reactive oxygen species (ROS), lactate production, cell viability, and apoptosis were evaluated in CRC cells following E2 treatment, PKM2 silencing, or a combination of both. Compared to individual treatments, combination therapy resulted in a significant reduction in cell viability and enhanced apoptosis. Glucose uptake and ROS production were markedly reduced in PKM2‐silenced E2‐treated cells. The data presented here suggest that E2 signaling combined with PKM2 inhibition cumulatively targets glucose metabolism in a manner that negatively impacts CRC cell growth. These findings hold promise for novel therapeutic strategies targeting altered metabolic pathways in CRC. Highlights: Colorectal cancer (CRC) cells exhibit a versatile metabolic profile that is responsive to changes in the tumor microenvironment.Estrogen (E2) signaling modulates glycolysis and reduces CRC cell growth and survival.Pyruvate kinase M2 (PKM2) inhibition also modulates glycolysis and reduces CRC cell growth.Combining E2 treatment with PKM2 inhibition precipitates significant cumulative antitumor effects in CRC cells. [ABSTRACT FROM AUTHOR]

During field surveys and culture procedures, large growth disparities in Anguilla japonica have been observed. However, the potential causes are unknown. This study explored differences in digestive ability, metabolic levels, and transcriptomic profiles of appetite-related genes between growth-retarded eel (GRE) and normal-growing eel (NGE) under the same rearing conditions. The results showed that growth hormone (gh) mRNA expression in GREs was considerably lower than NGEs. The levels of total protein (TP), total cholesterol (T-CHO), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), blood ammonia (BA), blood urea nitrogen (BUN), and alkaline phosphatase (ALP) in GREs were significantly lower than in NGEs. Conversely, levels of glucose (GLU), alanine aminotransferase (ALT), and aspartate transaminase (AST) were higher in GREs. The activities of SOD, CAT, and T-AOC levels were also significantly lower in GREs, as were the activities of glucose-related enzymes including hexokinase (HK), pyruvate kinase (PK), phosphoenolpyruvate carboxykinase (PEPCK), and glucose-6-phosphatase (G6PASE). Additionally, orexigenic genes (npy and ghrelin) were dramatically downregulated, whereas anorexigenic genes (crh and pyy) were significantly upregulated in GREs. These findings suggested that variances in growth hormone, metabolic activities, and appetite level could be associated with the different growth rates of A. japonica. The present research not only revealed the characteristics of the growth, metabolism, and appetite of GREs but also offered new perspectives into the substantial growth discrepancies in A. japonica, providing novel ideas for enhancing fish growth. [ABSTRACT FROM AUTHOR]

Objective: Finding biomarkers related to non-small cell lung cancer (NSCLC) is helpful for the diagnosis and precise treatment of lung cancer. The relationship between serum tumor M2-pyruvate kinase (TuM2-PK), carcinoembryonic antigen (CEA), and cytokeratin 19 fragment (CYFRA21-1) and NSCLC was analyzed. Methods: The serum levels of TuM2-PK, CEA, and CYFRA21-1 in 184 patients with the NSCLC group, 60 patients with the benign lung disease (BLD) group, and 90 healthy controls (HC) group were detected. The levels of TuM2-PK were measured by using an enzyme-linked immunosorbent assay. The detection methods of CEA and CYFRA21-1 were electrochemiluminescence. The receiver operating characteristic (ROC) curve was drawn to evaluate the diagnostic value of TuM2-PK, CEA, and CYFRA21-1 on NSCLC. The Kaplan–Meier survival curve was drawn to evaluate the survival status in NSCLC patients with different serum levels of TuM2-PK, CEA, and CYFRA21-1. Results: Serum levels of TuM2-PK, CEA, and CYFRA21-1 in the NSCLC group were significantly higher than those in the BLD group and the HC group (P <.01). Serum levels of TuM2-PK, CEA, and CYFRA21-1 in NSCLC patients were associated with the tumor lymph node metastasis stage (P <.05), lymph node metastasis (P <.05), and distant metastasis (P <.05). The ROC curve showed that the area under the curve of serum levels of TuM2-PK, CEA, and CYFRA21-1 was 0.814, 0.638, and 0.719, respectively, and that the combination of the above 3 was 0.918. The Kaplan–Meier survival curve showed that the 1-, 3- and 5-year survival rate in NSCLC patients with positive TuM2-PK, CEA, and CYFRA21-1 was significantly lower than that in NSCLC patients with negative TuM2-PK, CEA, and CYFRA21-1, respectively (P <.05). Conclusions: Serum TuM2-PK, CEA, and CYFRA21-1 levels have high clinical values in the diagnosis of NSCLC, and can effectively judge the prognosis of patients. [ABSTRACT FROM AUTHOR]

Metabolic dysfunction-associated fatty liver disease (MAFLD) presents a significant global health challenge, characterized by the accumulation of liver fat and impacting a considerable portion of the worldwide population. Despite its widespread occurrence, effective treatments for MAFLD are limited. The liver-specific isoform of pyruvate kinase (PKL) has been identified as a promising target for developing MAFLD therapies. Urolithin C, an allosteric inhibitor of PKL, has shown potential in preliminary studies. Expanding upon this groundwork, our study delved into delineating the structure-activity relationship of urolithin C via the synthesis of sulfone-based urolithin analogs. Our results highlight that incorporating a sulfone moiety leads to substantial PKL inhibition, with additional catechol moieties further enhancing this effect. Despite modest improvements in liver cell lines, there was a significant increase in inhibition observed in HepG2 cell lysates. Specifically, compounds 15d, 9d, 15e, 18a, 12d, and 15a displayed promising IC50 values ranging from 4.3 µM to 18.7 µM. Notably, compound 15e not only demonstrated a decrease in PKL activity and triacylglycerol (TAG) content but also showed efficient cellular uptake. These findings position compound 15e as a promising candidate for pharmacological MAFLD treatment, warranting further research and studies. [ABSTRACT FROM AUTHOR]

Mitapivat is a novel, first‐in‐class orally active pyruvate kinase activator approved by the US Food and Drug Administration in 2022 for the treatment of hemolytic anemia. There is no literature available regarding the identification of degradation impurities of mitapivat. The present study deals with the degradation behavior of mitapivat under various stress conditions such as hydrolytic, photolytic, thermal, and oxidative stress. The multivariate analysis found that the independent variables, that is, molarity, temperature, and time, are interacting with each other to affect the degradation of mitapivat. A specific, accurate, and precise high‐performance liquid chromatographic (HPLC) method was developed to separate mitapivat from its degradation products. The separation was achieved on the C‐18 column (250 mm × 4.6 mm × 5 µm) using the combination of 0.1% formic acid buffer and acetonitrile in gradient elution profile. The method was validated as per the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use Q2(R2) guideline. LC‐electrospray ionization‐Quadrupole‐time of flight was employed to identify degradation products. A total of seven novel degradation products of mitapivat were identified based on tandem mass spectrometry and accurate mass measurement. In‐silico toxicity of mitapivat and its degradation products was qualitatively evaluated by the DEREK toxicity prediction tool. [ABSTRACT FROM AUTHOR]

NAD-dependent deacetylase Sirt2 is involved in mammalian metabolic activities, matching energy demand with energy production and expenditure, and is relevant to a variety of metabolic diseases. Here, we constructed Sirt2 knockout and adeno-associated virus overexpression mice and found that deletion of hepatic Sirt2 accelerated primary obesity and insulin resistance in mice with concomitant hepatic metabolic dysfunction. However, the key targets of Sirt2 are unknown. We identified the M2 isoform of pyruvate kinase (PKM2) as a key Sirt2 target involved in glycolysis in metabolic stress. Through yeast two-hybrid and mass spectrometry combined with multi-omics analysis, we identified candidate acetylation modification targets of Sirt2 on PKM2 lysine 135 (K135). The Sirt2-mediated deacetylation-ubiquitination switch of PKM2 regulated the development of glycolysis. Here, we found that Sirt2 deficiency led to impaired glucose tolerance and insulin resistance and induced primary obesity. Sirt2 severely disrupted liver function in mice under metabolic stress, exacerbated the metabolic burden on the liver, and affected glucose metabolism. Sirt2 underwent acetylation modification of lysine 135 of PKM2 through a histidine 187 enzyme active site-dependent effect and reduced ubiquitination of the K48 ubiquitin chain of PKM2. Our findings reveal that the hepatic glucose metabolism links nutrient state to whole-body energetics through the rhythmic regulation of Sirt2. [ABSTRACT FROM AUTHOR]

Glioblastomas (GBMs) are characterized by high heterogeneity, involving diverse cell types, including those with stem‐like features contributing to GBM's malignancy. Moreover, metabolic alterations promote growth and therapeutic resistance of GBM. Depending on the metabolic state, antimetabolic treatments could be an effective strategy. Against this background, we investigated temporal and regional expression changes and co‐staining patterns of selected metabolic markers [pyruvate kinase muscle isozyme 1/2 (PKM1/2), glucose transporter 1 (GLUT1), monocarboxylate transporter 1/4 (MCT1/4)] in a rodent model and patient‐derived samples of GBM. To understand the cellular sources of marker expression, we also examined the connection of metabolic markers to markers related to stemness [Nestin, Krüppel‐like factor 4 (KLF4)] in a regional and temporal context. Rat tumour biopsies revealed a temporally increasing expression of GLUT1, higher expression of MCT1/4, Nestin and KLF4, and lower expression of PKM1 compared to the contralateral hemisphere. Patient‐derived tumours showed a higher expression of PKM2 and Nestin in the tumour centre vs. edge. Whereas rare co‐staining of GLUT1/Nestin was found in tumour biopsies, PKM1/2 and MCT1/4 showed a more distinct co‐staining with Nestin in rats and humans. KLF4 was mainly co‐stained with GLUT1, MCT1 and PKM1/2 in rat and human tumours. All metabolic markers yielded individual co‐staining patterns among themselves. Co‐staining mainly occurred later in tumour progression and was more pronounced in tumour centres. Also, positive correlations were found amongst markers that showed co‐staining. Our results highlight a link between metabolic alterations and stemness in GBM progression, with complex distinctions depending on studied markers, time points and regions. [ABSTRACT FROM AUTHOR]

Summary: Pyruvate kinase (PK) is a key enzyme of anaerobic glycolysis. The genetic heterogeneity of PK deficiency (PKD) is high, and over 400 unique variants have been identified. Twenty‐nine patients who had been diagnosed as PKD genetically in seven distinct paediatric haematology departments were evaluated. Fifteen of 23 patients (65.2%) had low PK levels. The PK:hexokinase ratio had 100% sensitivity for PKD diagnosis, superior to PK enzyme assay. Two novel intronic variants (c.695‐1G>A and c.694+43C>T) have been described. PKD should be suspected in patients with chronic non‐spherocytic haemolytic anaemia, even if enzyme levels are falsely normal. Total PKLR gene sequencing is necessary for the characterization of patients with PKD and for genetic counselling. [ABSTRACT FROM AUTHOR]

AIM: To clarify the effect of macrophage PKM2 deficiency on mucosal repair in ulcerative colitis (UC). METHODS: The gene expression and metabolic profiles in UC patients were first analyzed based on the following databases: PXD001608, GSE193677, and GSE214695. Using the macrophage-specific PKM2 elimination mice (PKM2AMAC), the functions of PKM2 in dextran sulfate sodium (DSS)-induced UC were clarified in vivo by analyzing the body weight, disease activity index (DAI) scores, HE staining, immunohistochemical staining, and expression of mucosal barrier markers. The impact of PKM2 on macrophage polarization was also investigated by flow cytometry, RNA sequencing and RT-qPCR in mouse bone marrow-derived macrophages (BMDMs) and THP-1 cells in vitro. RESULTS: Bioinformatic analysis suggested that the intestinal tissues of UC patients preferred glycolysis. The expression of PKM was parallel to the severity of UC in patients, and the expression of PKM2, but not PKM1, was elevated in macrophages of UC mice. In the DSS-induced UC mice, macrophage-specific PKM2 elimination significantly alleviates the body weight loss, diarrhea, rectal bleeding, colonic shorten, as well as decreased DAI scores and mucosal tissue damage. The BMDMs derived from the PKM2ΔMAC mice preferred the M2 polarization upon LPS or IL-4 stimulation to that derived from the wild-type mice, as indicated by the F4/80+ CD45+ CD86+ and F4/80+ CD45+ CD206+ population, as well as the expression of Ocln, F11r and Tjp-1. The RNA sequencing results indicated significant gene differential expression in PKM2 knockout mouse macrophages, which was enriched in biological processes such as leukocyte migration, tissue remodeling, and cytokine interactions. Macrophage PKM2 deficiency promoted the expression of mucosal repair factors (118, Cxcl1, Ptgs2 and Wnt6, which was further validated in PKM2 knockout THP-1 cells. CONCLUSION: The PKM2 deficiency in macrophages benifits the mucosal repair in UC status via facilitating the wound-healing macrophage polarization. [ABSTRACT FROM AUTHOR]

The 'Feizixiao' litchi cultivar, predominantly grown in Hainan Province, faces the issue of "sugar receding" during fruit ripening. The application of mixed foliar nutrients containing calcium and magnesium (Ca+Mg) during the fruit pericarp's full coloring stage was investigated to overcome this issue. Experimental trials unveiled significant alterations in litchi pulp physiochemical properties, including the main nutrient and flavor quality, the total respiration rates of the main respiratory pathways, and the activities of some important enzymes associated with Embden–Meyerhof–Parnas (EMP), the tricarboxylic acid cycle (TCA) and the pentose phosphate pathway (PPP). The Ca+Mg treatment showed higher sugar levels than the control (CK) during ripening. Notably, the application of Ca+Mg in litchi pulp inhibited respiration rates through the EMP, TCA, and PPP pathways, resulting in a strong effect. RNA sequencing analysis revealed the impact of Ca+Mg treatment on respiratory pathways, revealing differentially expressed genes (DEGs) such as pyruvate PK1, PK2 (pyruvate kinase), and PDC (pyruvate dehydrogenase complex), validated through qRT-PCR with a significant correlation to RNA-seq results. In general, Ca+Mg treatment during litchi fruit ripening overcame "sugar receding" by inhibiting the expression of respiration key metabolic pathway genes. These findings provide insights for enhancing cultivation management strategies. [ABSTRACT FROM AUTHOR]

Metabolic engineering for high productivity and increased robustness is needed to enable sustainable biomanufacturing of lactic acid from lignocellulosic biomass. Lactic acid is an important commodity chemical used for instance as a monomer for production of polylactic acid, a biodegradable polymer. Here, rational and model-based optimization was used to engineer a diploid, xylose fermenting Saccharomyces cerevisiae strain to produce L-lactic acid. The metabolic flux was steered towards lactic acid through the introduction of multiple lactate dehydrogenase encoding genes while deleting ERF2 , GPD1 , and CYB2. A production of 93 g/L of lactic acid with a yield of 0.84 g/g was achieved using xylose as the carbon source. To increase xylose utilization and reduce acetic acid synthesis, PHO13 and ALD6 were also deleted from the strain. Finally, CDC19 encoding a pyruvate kinase was overexpressed, resulting in a yield of 0.75 g lactic acid/g sugars consumed, when the substrate used was a synthetic lignocellulosic hydrolysate medium, containing hexoses, pentoses and inhibitors such as acetate and furfural. Notably, modeling also provided leads for understanding the influence of oxygen in lactic acid production. High lactic acid production from xylose, at oxygen-limitation could be explained by a reduced flux through the oxidative phosphorylation pathway. On the contrast, higher oxygen levels were beneficial for lactic acid production with the synthetic hydrolysate medium, likely as higher ATP concentrations are needed for tolerating the inhibitors therein. The work highlights the potential of S. cerevisiae for industrial production of lactic acid from lignocellulosic biomass. [Display omitted] • A xylose fermenting S. cerevisiae strain was engineered to produce L-lactic acid. • Rational and model-guided design was applied to increase lactic acid production. • 93 g/L of lactic acid at a yield of 0.84 g/g was produced from xylose. • A yield of 0.75 g/g was achieved in a synthetic lignocellulosic hydrolysate. • Modeling was used to understand the influence of oxygen in lactic acid production. [ABSTRACT FROM AUTHOR]

In this study, a genetic linkage map was developed based on simple sequence repeat (SSR) markers to aid in the identification and expression analysis of gene loci underlying the quantitative trait loci (QTL) of starch content (SC) in cassava (Manihot esculenta). A total of 912 polymorphic loci from 4,515 tested SSRs were mapped into 18 linkage groups. QTL analysis revealed four loci with highly significant associations with starch. Gene annotation was performed, and potential genes related to starch synthesis were identified. Of these, expression of four genes related to starch synthesis (Raffinose synthase [RS], Phosphoenolpyruvate kinase [PK], Glucose-6-phosphate [G6P], and Glycogen synthase kinase 3 [GSK-3]) was investigated by real-time PCR assays. The results found a statistically significant difference (p < 0.05) at 3 months after planting (MAP) in all the tested genes, whereas a higher expression was detected in the low-SC group with specific genotypes of linked markers. A higher level of expression was observed in the RS, PK, and G6P genes at six and nine MAP, indicating that starch accumulation mainly occurs after 3 MAP, during which the root system begins to form. The potential genes identified in this study could provide a better understanding of the starch biosynthesis mechanism, and could be useful for applications in marker-assisted selection to facilitate cassava breeding programs in the future. [ABSTRACT FROM AUTHOR]