Expression Of Lactate Dehydrogenase Research Articles

Interleukin-35 Suppresses CD8+ T Cell Activity in Patients with Viral Hepatitis-Induced Acute-on-Chronic Liver Failure.

Interleukin (IL)-35 is a newly indentified cytokine and induces immunotolerance via suppression of CD8+ T cell activity in chronic viral hepatitis. To investigate the modulatory function of IL-35 to CD8+ T cells in viral hepatitis-induced acute-on-chronic liver failure (ACLF). Fifty-five ACLF patients and 21 healthy controls were enrolled. Serum IL-35 concentration was measured by ELISA. Absolute accounts for T cells, immune checkpoint molecules, and cytotoxic molecules in CD8+ T cells were measured by flow cytometry and real-time PCR, respectively. Direct and indirect contact co-culture systems between CD8+ T cells and HepG2 cells were set up. The regulatory function of IL-35 to CD8+ T cells was assessed by measuring lactate dehydrogenase expression and cytokine production. Serum IL-35 concentration was elevated in ACLF patients and positively correlated with total bilirubin, but negatively correlated with prothrombin time activity. Peripheral CD8+ T cells showed exhausted phenotype in ACLF patients, which manifested as up-regulation of programmed death-1 (PD-1), cytotoxic T-lymphocyte-associated protein-4 (CTLA-4), and lymphocyte activation gene-3 (LAG-3) but down-regulation of perforin, granzyme B, and FasL. Recombinant IL-35 stimulation dampened cytotoxicity and interferon-γ production in both direct and indirect contact co-culture systems. This process was accompanied by elevation of PD-1, CTLA-4, and LAG3, as well as reduction of perforin, granzyme B, and FasL in CD8+ T cells. Elevated IL-35 suppressed both cytolytic and non-cytolytic activity of CD8+ T cells in ACLF patients.

Effects of the natural compound, oxyresveratrol, on the growth of Streptococcus mutans, and on biofilm formation, acid production, and virulence gene expression.

Streptococcus mutans is one of the major pathogens of dental caries. Oxyresveratrol, a natural compound found in plants, exerts inhibitory effects on many bacterial species but its effect on S.mutans is unknown. The objective of this study was to clarify the antibacterial effect of oxyresveratrol on S.mutans, including effects on basic viability, acidogenicity, acidurity, and extracellular polysaccharide synthesis. The expression of nine genes that encode virulence and protective factors in S.mutans was measured by qRT-PCR. Oxyresveratrol showed a dose-dependent inhibitory effect on survival of S.mutans. At 250μgml-1 , oxyresveratrol reduced the S.mutans survival rate, inhibited synthesis of water-insoluble glucans, compromised biofilm formation, and significantly down-regulated the expression of glucosyltransferase-I (gtfB) and glucosyltransferase-SI (gtfC). However, the enzymatic activity of lactate dehydrogenase protein was increased and the expression of lactate dehydrogenase (ldh) and ATP synthase subunit beta (atpD) genes were also up-regulated. Besides, glucosyltransferase S (gtfD) up-regulation indicated that water-soluble glucan synthesis was promoted.The vicR, liaR, and comDE genes, which exert a self-protective function in response to external stress, were also up-regulated. In conclusion, oxyresveratrol inhibited the growth of S.mutans and also reduced biofilm formation, acid production, and synthesis of water-insoluble glucans by this organism. In addition, oxyresveratrol also activated a series of S.mutans self-protection mechanisms.

Imaging breast cancer using hyperpolarized carbon-13 MRI

Our purpose is to investigate the feasibility of imaging tumor metabolism in breast cancer patients using 13C magnetic resonance spectroscopic imaging (MRSI) of hyperpolarized 13C label exchange between injected [1-13C]pyruvate and the endogenous tumor lactate pool. Treatment-naïve breast cancer patients were recruited: four triple-negative grade 3 cancers; two invasive ductal carcinomas that were estrogen and progesterone receptor-positive (ER/PR+) and HER2/neu-negative (HER2-), one grade 2 and one grade 3; and one grade 2 ER/PR+ HER2- invasive lobular carcinoma (ILC). Dynamic 13C MRSI was performed following injection of hyperpolarized [1-13C]pyruvate. Expression of lactate dehydrogenase A (LDHA), which catalyzes 13C label exchange between pyruvate and lactate, hypoxia-inducible factor-1 (HIF1α), and the monocarboxylate transporters MCT1 and MCT4 were quantified using immunohistochemistry and RNA sequencing. We have demonstrated the feasibility and safety of hyperpolarized 13C MRI in early breast cancer. Both intertumoral and intratumoral heterogeneity of the hyperpolarized pyruvate and lactate signals were observed. The lactate-to-pyruvate signal ratio (LAC/PYR) ranged from 0.021 to 0.473 across the tumor subtypes (mean ± SD: 0.145 ± 0.164), and a lactate signal was observed in all of the grade 3 tumors. The LAC/PYR was significantly correlated with tumor volume (R = 0.903, P = 0.005) and MCT 1 (R = 0.85, P = 0.032) and HIF1α expression (R = 0.83, P = 0.043). Imaging of hyperpolarized [1-13C]pyruvate metabolism in breast cancer is feasible and demonstrated significant intertumoral and intratumoral metabolic heterogeneity, where lactate labeling correlated with MCT1 expression and hypoxia.

TRIM59, amplified in ovarian cancer, promotes tumorigenesis through the MKP3/ERK pathway.

Tripartite motif containing 59 (TRIM59) functions as an oncoprotein in various human cancers including ovarian cancer. In this study, we found that TRIM59 gene amplification was prevalent in ovarian cancer tissues, and its amplification was significantly correlated with poorer overall survival. Moreover, knockdown of TRIM59 in SKOV3 and OVCAR3 cells, which had relatively high level of TRIM59, suppressed glucose uptake and lactate production. TRIM59 knockdown also decreased the expression of c-Myc and lactate dehydrogenase A, and the phosphorylation of extracellular signal-regulated kinase (ERK). TRIM59 overexpression in A2780 cells, which expressed low level of TRIM59, showed reverse effects. Notably, treatment with an ERK inhibitor (PD98059) completely abolished the oncogenic effects of TRIM59 overexpression. Interestingly, TRIM59 increased the ubiquitination of MAP kinase phosphatase 3 (MKP3), which may dephosphorylate and inactivate ERK. Ectopic expression of MKP3 inhibited the promoting effects of TRIM59 on glycolysis and the phosphorylation of ERK. TRIM59 protein expression was negatively correlated with MKP3 protein expression in ovarian cancer tissues. Finally, TRIM59 amplification potently affected the anticancer effect of 3-bromopyruvate, an inhibitor of glycolysis, in ovarian cancer cells and patient-derived xenograft. In conclusion, these results suggest that TRIM59 may regulate glycolysis in ovarian cancer via the MKP3/ERK pathway.

Rhubarb-Aconite Decoction (RAD) Drug-Containing Serum Alleviated Endotoxin-Induced Oxidative Stress Injury and Inflammatory Response in Caco-2 Cells In Vitro.

Rhubarb-Aconite Decoction (RAD), a famous Chinese medicine prescription, has been widely used for treating intestinal injury. However, the effect of RAD on intestinal epithelial cells is unclear. The aim of this study was to investigate the effects of RAD drug-containing serum on the oxidative stress injury and inflammatory response induced by endotoxin (ET) in Caco-2 cells in vitro. Lipid peroxide malondialdehyde (MDA), lactate dehydrogenase (LDH), caspase-11, tumor necrosis factor-α(TNF-α), interleukin-3(IL-3), and cytokeratin (CK)18, adenosine triphosphate (ATP) activity, and intracellular free calcium ion levels were measured. The results showed that ET triggered the activation of caspase-11 and the massive release of TNF-α, increased the inhibitory rate of cell growth, MDA, and LDH expressions in Caco-2 cells. Moreover, RAD drug-containing serum could inhibit caspase-11 activation, decrease the release of TNF-α and IL-3, reduce intracellular free calcium ion, and enhance CK 18 expression and ATP activity. These novel findings demonstrated that ET-induced oxidative stress injury and inflammatory response of Caco-2 cells were improved by RAD drug-containing serum, indicating that RAD may be a good choice for the treatment of intestinal injury.

Function and Gene Expression of Islets Experimentally Transplanted to Muscle and Omentum

Islet transplantation to the liver is a potential curative treatment for patients with type 1 diabetes. Muscle and the greater omentum are two alternative implantation sites, which can provide excellent engraftment and hold potential as future sites for stem-cell-derived beta-cell replacement. We evaluated the functional outcome after islet transplantation to muscle and omentum and found that alloxan-diabetic animals were cured with a low number of islets (200) at both sites. The cured animals had a normal area under the curve blood glucose response to intravenous glucose, albeit animals with intramuscular islet grafts had increased 120-min blood glucose levels. They also demonstrated an exaggerated counter regulatory response to hypoglycemia. The expression of genes important for beta-cell function was, at both implantation sites, comparable to that in native pancreatic islets. The gene expression of insulin (INS1 and INS2) and glucose transporter-2 was even increased, and the expression of lactate dehydrogenase decreased, at both sites when compared to native islets. We conclude that muscle and omentum provide excellent conditions for engraftment of transplanted islets. When compared to control, 200 islets implanted to the omentum displayed a restored glucose tolerance, whereas animals with intramuscular islet grafts of similar size displayed mild glucose intolerance.

Altered expression of lactate dehydrogenase and monocarboxylate transporter involved in lactate metabolism in broiler wooden breast

Wooden breast (WB) results in significant losses to the broiler industry due to reductions in meat quality. While the etiology of WB is unknown, it is believed to be associated with localized hypoxia and decreased lactate levels in skeletal muscles, indicating the presence of altered lactate metabolism in WB. We hypothesized that the expression levels of the major signaling molecules that control lactate metabolism, including lactate dehydrogenases (LDHA and LDHB) and monocarboxylate transporters (MCT1 and MCT4), were altered in WB. Therefore, the objectives of this study were to evaluate whether there were changes in mRNA and protein levels of LDHA, LDHB, MCT1, and MCT4 in WB compared to normal breast (NB) muscles. Biochemical analysis for LDH enzyme activity in NB and WB muscles was studied. MicroRNA375 (miR-375) expression, known to be inversely associated with LDHB protein expression in human cells, was also investigated. The level of LDHA mRNA was 1.7-fold lower in WB tissues than in NB tissues (P < 0.0001). However, the LDHA protein levels were similar in WB and NB tissues. In contrast, the levels of LDHB mRNA and protein were 8.4-fold higher (P < 0.002) and 13.6-fold higher (P < 0.02) in WB than in NB tissues, respectively. The level of miR-375 was not different between WB and NB muscles. The specific LDH isoenzyme activity that converted lactate to pyruvate was 1.8-fold lower in WB compared to NB tissues (P < 0.01). The level of MCT1 mRNA was 2.3-fold higher in WB than those in NB muscles (P < 0.02). However, this upregulation was not observed with MCT1 protein expression levels. The expression levels of MCT4 mRNA and protein were elevated 2.8-fold (P < 0.02) and 3.5-fold (P < 0.004) in WB compared to NB tissues, respectively. Our current findings suggest the potential roles of LDHB and MCT4 on lactate metabolism and provide a unique molecular elucidation for altered lactate homeostasis in WB muscles of broilers.

MiR-345-3p attenuates apoptosis and inflammation caused by oxidized low-density lipoprotein by targeting TRAF6 via TAK1/p38/NF-kB signaling in endothelial cells

AimsAtherosclerosis is a risk factor for coronary heart disease and cerebral infarction. Recent reports show decreased miR-345-3p in apolipoprotein-E deficient mice. Our study aimed to determine the biological activities of miR-345-3p in endothelial cells exposed to oxidized low-density lipoprotein (oxLDL). Main methodsHuman umbilical vein endothelial cells were transfected with miR-345-3p mimic and then exposed to oxLDL. Expression of miR-345-3p was assayed using real time-qPCR (RT-qPCR). Cell viability, lactate dehydrogenase leakage, apoptosis, and protein levels of p53, cleaved-caspase 3 (c-caspase 3), Bax, and Bcl-2 were measured using a CCK-8 assay, LDH Cytotoxicity Assay Kit, Cell Death Detection ELISA Plus Kit, and western blot, respectively. Expression of tumor necrosis factor (TNF)-α, interleukin (IL)-6, ICAM-1, VCAM-1, and E-selectin also was determined. The binding between miR-345-3p and TNF-receptor-associated factor 6 (TRAF6) was validated by dual-luciferase reporter assay. The mRNA and protein levels of TRAF6 were determined by RT-qPCR and western blot. Expression levels of TAK1/p38/NF-κB pathway-related proteins were evaluated by western blot. Key findingsThe results showed that oxLDL reduced miR-345-3p expression. Upregulation of miR-345-3p impeded oxLDL-induced growth inhibition, lactate dehydrogenase leakage, apoptosis, and expression of TNF-α, IL-6, ICAM-1, VCAM-1, and E-selectin. A dual-luciferase reporter assay demonstrated that miR-345-3p directly targeted TRAF6. TRAF6 overexpression reversed the biological activities of miR-345-3p. MiR-345-3p inhibited activation of the TAK1/p38/NF-κB pathway by targeting TRAF6 in the presence of oxLDL. SignificanceMiR-345-3p prevented oxLDL-induced apoptosis and inflammation through the TAK1/p38/NF-κB pathway via targeting TRAF6.

Proteasome inhibition disrupts the metabolism of fumarate hydratase- deficient tumors by downregulating p62 and c-Myc

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is characterized by germline mutations of the FH gene that encodes for the TCA cycle enzyme, fumarate hydratase. HLRCC patients are at risk for the development of an aggressive form of type 2 papillary renal cell carcinoma. By studying the mechanism of action of marizomib, a proteasome inhibitor able to cross the blood-brain barrier, we found that it modulates the metabolism of HLRCC cells. Marizomib decreased glycolysis in vitro and in vivo by downregulating p62 and c-Myc. C-Myc downregulation decreased the expression of lactate dehydrogenase A, the enzyme catalyzing the conversion of pyruvate to lactate. In addition, proteasomal inhibition lowered the expression of the glutaminases GLS and GLS2, which support glutamine metabolism and the maintenance of the redox balance. Thus, in HLRCC cells, proteasome inhibition disrupts glucose and glutamine metabolism, restricting nutrients and lowering the cells’ anti-oxidant response capacity. Although the cytotoxicity induced by proteasome inhibitors is complex, the understanding of their metabolic effects in HLRCC may lead to the development of effective therapeutic strategies or to the development of markers of efficacy.

Technical-grade chlordane compromises rat Sertoli cells proliferation, viability and metabolic activity

Environmental contaminants are a daily presence in human routine. Multiple studies highlight the obesogenic activity of some chemicals. Moreover, these compounds have been suggested as a cause of male subfertility and/or infertility. Technical-grade chlordane (TGC) is classified as an endocrine-disruptor chemical, while its classification as obesogen is controversial. Herein, we studied the influence of TGC on Sertoli cells (SCs) metabolism. Rat Sertoli cells (rSCs) were cultured without and in the presence of increasing concentrations (1, 10 and 1000 nM) of TGC. The viability, proliferation, metabolic activity and the metabolic profile of rSCs was assessed. Expression of key glycolysis-related enzymes, transporters and biomarkers of oxidative damage were also evaluated. Our results show that exposure to higher concentrations of TGC decreases SCs proliferation and viability, which was accompanied by increased glucose consumption associated with an upregulation of Glut3 levels. As a result, pyruvate/lactate production were enhanced thus increasing the glycolytic flux in cells exposed to 1000 nM TGC, although lactate dehydrogenase expression and activity did not increase. Notably, biomarkers associated with oxidative damage remained unchanged after exposure to TGC. This is the first report showing that TGC alters glucose rSCs metabolism and the nutritional support of spermatogenesis with consequences for male fertility.

Active pyruvate dehydrogenase and impaired gluconeogenesis in orthotopic hepatomas of rats

BackgroundTherapies targeting altered activity of pyruvate dehydrogenase (PDH) and pyruvate carboxylase (PC) have been proposed for hepatomas. However, the activities of these pathways in hepatomas in vivo have not been distinguished. Here we examined pyruvate entry into the tricarboxylic acid (TCA) cycle through PDH versus PC in vivo using hepatoma-bearing rats. MethodsHepatoma-bearing rats were generated by intrahepatic injection of H4IIE cells. Metabolism of 13C-labeled glycerol, a physiological substrate for both gluconeogenesis and energy production, was measured with 13C NMR analysis. The concentration of key metabolites and the expression of relevant enzymes were measured in hepatoma, surrounding liver, and normal liver. ResultsIn orthotopic hepatomas, pyruvate entry into the TCA cycle occurred exclusively through PDH and the excess PDH activity compared to normal liver was attributed to downregulated pyruvate dehydrogenase kinase (PDK) 2/4. However, pyruvate carboxylation via PC and gluconeogenesis were minimal, which was linked to downregulated forkhead box O1 (FoxO1) by Akt activity. In contrast to many studies of cancer metabolism, lactate production in hepatomas was not increased which corresponded to reduced expression of lactate dehydrogenase. The production of serine and glycine in hepatomas was enhanced, but glycine decarboxylase was downregulated. ConclusionsThe combination of [U-13C3]glycerol and NMR analysis enabled investigation of multiple biochemical processes in hepatomas and surrounding liver. We demonstrated active PDH and other related metabolic alterations in orthotopic hepatomas that differed substantially not only from the host organ but also from many earlier studies with cancer cells.

Prognostic Value of Lactate Dehydrogenase Expression in Different Cancers: A Meta-Analysis

This meta-analysis was performed to elucidate the association between the expression of lactate dehydrogenase (LDH) and the prognosis of various malignant neoplasms. Qualified studies were systematically identified from relevant databases, including PubMed, Cochrane Library, Embase, WanFang, and HowNet. A total of 17 eligible studies with 4,176 patients that complied with the inclusion criteria were enrolled in this meta-analysis. The 17 articles were published from 2011 to 2018. The hazard ratio (HR) and 95% confidence interval (95%CI) were obtained from the selected studies. The analysis that included all LDH-related studies showed a significant association with the overall survival (OS) outcome (HR = 1.74, P = 0.001) but exhibited an insignificant association with the disease-free survival (DFS) or recurrence-free survival (RFS) outcome (HR = 1.40, P = 0.072). High lactate dehydrogenase A (LDHA) expression was significantly relevant to inferior OS (HR = 1.88, 95%CI: 1.37-2.59) and DFS or RFS (HR = 1.56, 95%CI: 1.29-1.89). High LDH expression and the prognostic outcome of various cancer patients are significantly correlated. High LDHA expression is a promising biomarker for forecasting the survival of patients and the recurrence of different cancers in these patients. Further associative studies are required due to the complex role of LDH genes.

Targeting Glycolysis through Inhibition of Lactate Dehydrogenase Impairs Tumor Growth in Preclinical Models of Ewing Sarcoma.

Altered cellular metabolism, including an increased dependence on aerobic glycolysis, is a hallmark of cancer. Despite the fact that this observation was first made nearly a century ago, effective therapeutic targeting of glycolysis in cancer has remained elusive. One potentially promising approach involves targeting the glycolytic enzyme lactate dehydrogenase (LDH), which is overexpressed and plays a critical role in several cancers. Here, we used a novel class of LDH inhibitors to demonstrate, for the first time, that Ewing sarcoma cells are exquisitely sensitive to inhibition of LDH. EWS-FLI1, the oncogenic driver of Ewing sarcoma, regulated LDH A (LDHA) expression. Genetic depletion of LDHA inhibited proliferation of Ewing sarcoma cells and induced apoptosis, phenocopying pharmacologic inhibition of LDH. LDH inhibitors affected Ewing sarcoma cell viability both in vitro and in vivo by reducing glycolysis. Intravenous administration of LDH inhibitors resulted in the greatest intratumoral drug accumulation, inducing tumor cell death and reducing tumor growth. The major dose-limiting toxicity observed was hemolysis, indicating that a narrow therapeutic window exists for these compounds. Taken together, these data suggest that targeting glycolysis through inhibition of LDH should be further investigated as a potential therapeutic approach for cancers such as Ewing sarcoma that exhibit oncogene-dependent expression of LDH and increased glycolysis. SIGNIFICANCE: LDHA is a pharmacologically tractable EWS-FLI1 transcriptional target that regulates the glycolytic dependence of Ewing sarcoma.

The expression of serum lactate dehydrogenase in canine oral tumors

The expression of serum lactate dehydrogenase in canine oral tumors

The chronic effect of amorphous silica nanoparticles and benzo[a]pyrene co-exposure at low dose in human bronchial epithelial BEAS-2B cells.

As the main components of fine particulate matter (PM2.5), silica nanoparticles (SiNPs) and benzo[a]pyrene (B[a]P) have attracted increasing attention recently. However, co-exposure to SiNPs and B[a]P causes pulmonary injury by aggravating toxicity via an unknown mechanism. This study aimed at investigating the toxicity caused due to long-term co-exposure to SiNPs and B[a]P on pulmonary systems at low dose using human bronchial epithelial (BEAS-2B) cells. The characterizations of SiNPs and B[a]P were done by transmission electron microscopy (TEM) and zeta potential granulometry. Cytotoxicity is evaluated using cell counting kit-8 (CCK-8) assay and lactate dehydrogenase (LDH) activity; oxidative stress, cell cycle and apoptosis were assessed by flow cytometry, and inflammatory factors were detected using a Luminex xMAP system. Results show an obvious inhibition of cell proliferation and a marked increase in the LDH expression in the BEAS-2B cells after long-term co-exposure. Furthermore, long-term co-exposure is the most potent in generating intracellular ROS, thus causing inflammation. Cellular apoptotic rate is enhanced in the co-exposed group at low dose. Moreover, the long-term co-exposure induces significant cell cycle arrest, increasing the proportion of cells at the G2/M phase, while decreasing those at the G0/G1 phase. This study is the first attempt to reveal the severe synergistic and additive toxic effects induced by SiNPs and B[a]P co-exposure for long-term in BEAS-2B cells even at low dose.

Enhanced glycolytic metabolism supports transmigration of brain-infiltrating macrophages in multiple sclerosis.

The migration of leukocytes into the CNS drives the neuropathology of multiple sclerosis (MS). This penetration likely utilizes energy resources that remain to be defined. Using the experimental autoimmune encephalomyelitis (EAE) model of MS, we determined that macrophages within the perivascular cuff of post-capillary venules are highly glycolytic as manifested by strong expression of lactate dehydrogenase A (LDHA) that converts pyruvate to lactate. These macrophages expressed prominent levels of monocarboxylate transporter-4 (MCT-4) specialized in secreting lactate from glycolytic cells. The functional relevance of glycolysis was confirmed by siRNA-mediated knockdown of LDHA and MCT-4, which decreased lactate secretion and macrophage transmigration. MCT-4 was in turn regulated by EMMPRIN (CD147) as determined through co-expression/co-immunoprecipitation studies, and siRNA-mediated EMMPRIN silencing. The functional relevance of MCT-4/EMMPRIN interaction was affirmed by lower macrophage transmigration in culture using the MCT-4 inhibitor, α-cyano-4-hydroxy-cinnamic acid (CHCA), a cinnamon derivative. CHCA also reduced leukocyte infiltration and the clinical severity of EAE. Relevance to MS was corroborated by the strong expression of MCT-4, EMMPRIN and LDHA in perivascular macrophages in MS brains. These results detail the metabolism of macrophages for transmigration from perivascular cuffs into the CNS parenchyma and identifies CHCA and diet as potential modulators of neuro-inflammation in MS.

Oleuropein suppresses oxidative, inflammatory, and apoptotic responses following glycerol-induced acute kidney injury in rats

AimHere, we evaluated the possible protective effects of oleuropein, the major phenolic constituent in virgin olive oil against glycerol-induced acute kidney injury (AKI) in rats. Main methodsTwenty-eight Sprague Dawley rats were allocated equally into four groups as follows: control group, oleuropein group (50 mg/kg body weight), AKI group and the oleuropein + AKI group. AKI was induced by injecting 50% glycerol (10 ml/kg body weight) intramuscularly. Key findingsGlycerol injection increased the kidney relative weight as well as rhabdomyolysis (RM)- and AKI-related index levels, including the levels of creatine kinase, lactate dehydrogenase, creatinine, urea, and Kim-1 expression. Additionally, alteration in oxidative conditions in renal tissue was recorded, as confirmed by the elevated malondialdehyde and nitric oxide levels and the decreased glutathione content. Concomitantly, the protein and mRNA expression levels of antioxidant enzymes were suppressed. Moreover, Nfe2l2 and Hmox1 mRNA expression was also downregulated. Glycerol triggered inflammatory reactions in renal tissue, as evidenced by the increased pro-inflammatory cytokines and Ccl2 protein and mRNA expression, whereas myeloperoxidase activity was increased. Furthermore, glycerol injection enhanced apoptotic events in renal tissue by increasing the expression of the pro-apoptotic proteins and decreasing that of anti-apoptotic. However, oleuropein administration reversed the molecular, biochemical, and histological alterations resulting from glycerol injection. SignificanceOur data suggest that oleuropein has potential as an alternative therapy to prevent or minimize RM incidence and subsequent development of AKI, possibly due to its potent anti-stress, anti-inflammatory, and anti-apoptotic effects.

Expression of lactate dehydrogenase is induced during hypoxia via HIF-1 in the mud crab Scylla paramamosain

Lactate dehydrogenase (LDH) is a key enzyme involved in anaerobic metabolism in most organisms. In the present study, we determined the structure and function of LDH sequence in Scylla paramamosain (SpLDH) by gene cloning, expression and RNA interference techniques in order to explore the genetic characteristics of LDH and its relationship with HIF-1 during hypoxia. The full-length cDNA was 1453 bp with an open reading frame (ORF) of 996 bp, and encoded a polypeptide of 332 amino acids. Homology analysis showed that the SpLDH gene is highly similar to arthropods. The SpLDH transcript increased after hypoxia in all tested tissues. The silencing of HIF-1 blocked the increase in LDH mRNA and activity, which were induced by hypoxia in gill and muscle tissues. Our results indicated that SpLDH expression was regulated transcriptionally by HIF-1.

Abstract 4370: Knockdown of PKM2 induces autophagic cell death via Akt/mTOR pathway in human prostate cancer cells

Abstract Pyruvate kinase M2 (PKM2) is crucial for aerobic glycolysis that is highly expressed in the various cancer tissues. Although high expression of PKM2 is observed in prostate tumor tissues, its functional role against affecting cancer metabolism is not clearly understood. Herein, we investigate its role in regulating autophagy and its associated pathways. In the current study, various PKM2-siRNA constructs were used to knockdown the PKM2 expression and observed its cellular pathways on autophagy. Cell viability was significantly reduced in PKM2-siRNA transfected prostate cancer cells, DU145. Acridine orange staining and immunoblotting analysis showed that downregulation of PKM2 markedly increased autophagy cell death. In addition, immunoblotting analysis exhibited the blocking the protein kinase B (Akt) and mTOR1 pathways, which subsequently down-regulated the expression of glycolytic enzymes lactate dehydrogenase A (LDHA) and Glucose transporter 1 (GLUT1). To the best of our knowledge, this is the first study that inhibition of PKM2 changes in cancer cell metabolism and induces autophagy, thus, providing new perspectives into the mechanism of its anticancer activity against prostate cancer, DU145. Citation Format: Prasanta Dey, Amit Kundu, Byung Mu Lee, Hyung Sik Kim. Knockdown of PKM2 induces autophagic cell death via Akt/mTOR pathway in human prostate cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4370.

6-Gingerol protects cardiocytes H9c2 against hypoxia-induced injury by suppressing BNIP3 expression

Background Cardiomyocytes loss is the predominant pathogenic characteristic in the hypoxia-induced injury. Meanwhile, it has been corroborated that Bcl-2 E1B 19-KDa interacting protein 3 (BNIP3) provokes apoptosis and autophagy. For moderating cardiomyocytes loss, we initially probed the cyto-protection effects of 6-Gingerol (6 G), meanwhile, its potential mechanisms associated with BNIP3 were elucidated in our studies. Methods We pretreated cardiomyocytes H9c2 cells with 6 G at different concentrations (0–100 μM) before exposure to hypoxia. Thereafter, the cell viability, lactate dehydrogenase (LDH), apoptosis and protein expression were respectively assessed using cell counting kit-8 and methyl thiazolyl tetrazolium (MTT) assay, LDH assay kit, Annexin V-fluorescein isothiocyannate/propidium iodide (Annexin V-FITC/PI) apoptosis detection kit and Western blotting analysis. In addition, we also analyzed BNIP3 level after treatment. Moreover, we enforced the exogenous overexpression of BNIP3 and then evaluated the cell viability, apoptosis, and protein level again. Results In our present work, we observed that the cell viability was promoted by 6 G in the hypoxia-induced H9c2 cells in a dose-dependent manner. Moreover, hypoxia-induced LDH release, apoptosis and autophagy were inhibited by 6 G pretreatment through promoting phosphorylation of PI3K, AKT and mTOR. Remarkably, accumulation of BNIP3 protein was significantly reduced by 6 G in hypoxia-induced H9c2 cells. Mechanistically, 6 G initiated the phosphorylated expression of PI3K, AKT and mTOR by down-regulating BNIP3 with reducing cardiomyocytes apoptosis and autophagy. Conclusion Hypoxia-induced cardiomyocytes injury was ameliorated by 6 G through suppressing BNIP3 expression with triggering PI3K/AKT/mTOR signalling pathway.