Altered Lactate Dehydrogenase Research Articles

Alpha-lipoic acid enhances ischemic postconditioning-mediated improvement of myocardial infarction and apoptosis in diabetic rats with ischemia/reperfusion injury.

This work evaluated the combined effects of alpha-lipoic acid (ALA) and ischemic postconditioning (Post) on myocardial infarction and cell death in rats with chronic type-II diabetes following ischemia/reperfusion injury. The rats received a high-fat diet and were given one intraperitoneal injection of 35 mg/kg streptozotocin to induce chronic diabetes. They were then pretreated with ALA (100 mg/kg/day, orally) for 5 weeks before undergoing ischemia/reperfusion (I/R) insult. The hearts experienced 35 min regional ischemia through ligating the left anterior descending coronary artery, followed by 60 min reperfusion. The Post protocol involved 6 cycles of a 10/10 s algorithm, applied during the early stage of reperfusion. The use of Post alone did not significantly alter lactate dehydrogenase and infarct size levels, while ALA showed positive effects. Similar findings were observed for apoptotic changes with single treatments. However, the concurrent administration of ALA and Post significantly reduced the protein expressions of Bax, Bax/Bcl2, and cleaved caspase-3 while increasing Bcl2 expression. Additionally, the histopathological findings of the combined therapy were superior to those of single treatments. The concomitant use of ALA and Post effectively inhibited apoptosis, leading to cardiac recovery after I/R injury in diabetic conditions. This strategy could improve outcomes for preserving diabetic hearts following I/R insults.

N‐cadherin‐mediated Regulation of Metabolism in Oral Precancer

Cadherins are transmembrane proteins traditionally known to have a structural role in cellular adhesion. These proteins display tissue-specific changes in expression that have been correlated with poor prognosis in a variety of cancers. N-cadherin expression specifically has been associated with poor oral cancer prognosis. An estimated 80% of oral cancers exhibit aberrant N-cadherin expression. We have previously shown that cadherins can alter growth factor receptor signaling cascades, which have been shown in other studies to direct metabolic changes essential to oral cancer metastasis. The goal of the current study was to characterize the mechanism(s) by which abnormal expression of N-cadherin may alter metabolic activity in oral epithelia. We have utilized a dysplastic oral keratinocyte (DOK) line to develop retrovirally-transduced cells which express control levels or reduced levels of N-cadherin protein. Using these lines, we evaluated the effect of N-cadherin expression on EGF-dependent EGFR phosphorylation as well as downstream effectors within the mammalian target of rapamycin (mTOR) signaling pathway. Western blot analysis of our EGF-treated DOK lines suggested that N-cadherin expression suppressed phosphorylation of EGFR at Tyr 1068, which plays a role in EGFR degradation, and Tyr 1045, which can mediate cell survival through activation of signal transducer and activator of transcription 3 (STAT3). We also found minimal changes in phosphorylation of Tyr 992, a phosphosite associated with mitogenic signaling. EGFR activation has been shown to direct metabolism through phosphatidyl inositol-3 kinase (PI3K)/Akt/mTOR signaling. Our data indicated that N-cadherin expression is necessary for maximal EGF-directed phosphorylation of both Akt at Ser 473 and of mTORC1 at Ser 2448. mTOR has been shown to increase synthesis of the transcription factor hypoxia inducible factor-1 alpha (HIF-1 alpha) to redirect glycolytic intermediates from oxidative metabolism to anaerobic glycolysis by way of lactate dehydrogenase (LDH), a hallmark of the Warburg effect. We found that N-cadherin expression suppressed HIF-1 alpha synthesis but did not appear to alter lactate dehydrogenase expression. It is important to note that reduced expression of N-cadherin did not alter levels of either E- or P-cadherin expression. Taken together, these findings suggest a role for N-cadherin in the regulation of mTOR-related metabolic signaling, and in modulation of the Warburg effect in oral precancer. Given the high incidence of N-cadherin expression in oral cancer as well as its correlation with poor prognosis, elucidating the mechanisms by which N-cadherin regulates metabolism could reveal novel and promising targets for future therapeutic approaches.

MULTIPLE ORAL FISTULA AND TRISMUS LEADING TO A SURPRISING DIAGNOSIS

We report a rare case of late diagnosis of malignant osteopetrosis due to clinical investigation of multiple intraoral fistulae and trismus in a 35-year-old male patient. The patient reported history of various complicated dental extractions during his life, facial scars that he could not attribute with certainty to old external fistulas, but besides his blindness, present since his childhood, he never had any other significant disease previously diagnosed. A computerized scanning tomography was performed and revealed a marblelike sclerotic pattern of all cranial bones, thickened parietal bone, and a narrowing of the encephalic space and optic canal. Further laboratorial and imaging studies revealed complete sclerosed bone of the chest and pelvis, anemia, reticulocitosis, extramedullary hematopoiesis, altered lactate dehydrogenase, and acid phosphatases. An interdisciplinary treatment was started with medical and dental care monitoring, and the patient is still under follow-up care after 1 year.

The therapeutic effect of aucubin-supplemented hyaluronic acid on interleukin-1beta-stimulated human articular chondrocytes

BackgroundInjection of exogenous hyaluronic acid (HA) into the joint capsule improves symptoms of early stage osteoarthritis (OA). However, reactive oxygen species degrade HA into small oligosaccharides that can elicit pro-inflammatory responses. Likewise, disturbance of the antioxidant enzyme system and generation of oxidative stress by pro-inflammatory cytokines worsen knee OA. Accordingly, we proposed the use of aucubin, an antioxidant and anti-inflammatory compound, as a versatile adjuvant to HA for treating OA. MethodsPrimary human chondrocytes were cultured in media supplemented with aucubin in a series of concentrations (0, 0.01, 0.1, 1, and 10 μg/ml) to study dose-dependent toxicity. We then evaluated the therapeutic effects of HA (100 μg/ml) supplemented with aucubin (10 μg/ml) on interleukin-1 beta (IL-1β, 10 ng/ml)-stimulated chondrocytes. ResultsThe use of aucubin did not change cell viability or alter lactate dehydrogenase release to normal chondrocytes. Although the proliferation and sulfated glycosaminoglycan production were not affected, aucubin partially restored the hypertrophic transformation of chondrocytes. Relative to treatment with HA or aucubin alone, real-time PCR revealed that aucubin-supplemented HA down-regulated the mRNA levels of tumor necrosis factor-alpha (TNF-α), corrected collagen type 1 and aggrecan, and up-regulated tissue inhibitor of metalloproteinase 1. Moreover, ELISA testing also showed a reduced TNF-α production. Although superoxide dismutases activity was still distributed, aucubin restored total antioxidant capacity of IL-1β-stimulated chondrocytes. Western blotting further showed that aucubin inhibited cyclooxygenase-2 and regulated the nuclear factor (erythroid-derived 2)-like 2 pathway. ConclusionAucubin can enhance the anti-catabolic and anti-inflammatory effects of HA on OA chondrocytes.

Clinical and epidemiological profile of patients with early stage mycosis fungoides

Background:Mycosis fungoides is the most common form of primary cutaneous lymphoma, with an indolent, slowly progressive course and 88% five-year survival rate. The diagnosis is challenging, especially in the early stages, and usually relies on a good clinical-histopathological correlation. Objective:The aim was to establish the clinical and epidemiological profile of patients with early-stage mycosis fungoides. Methods:This was a retrospective cross-sectional observational study with an exploratory analysis. Outcome variables were disease progression and mycosis fungoides-related death. Results:One hundred and two patients were included. The majority were white males, with a mean age of 55.6 years. Mean time from onset of lesions to diagnosis was 51.08 months. The majority of patients were classified as IB stage according to TNMB. Mean follow-up time was 7.85 years. Disease progression was seen in 29.4% of the patients. Death related to the disease occurred in 7.9% of patients. Plaque lesions, involvement of more than 10% of the body surface, altered lactate dehydrogenase and beta-2-microglobulin, and stage IB were significantly associated with disease progression, and altered lactate dehydrogenase and beta-2-microglobulin also correlated with higher frequency of deaths. Study limitations:Small sample and retrospective design. Conclusions:The clinical and epidemiological profile of patients with early-stage mycosis fungoides in our sample corroborates reports in the literature. Diagnostic delay in our series is also consistent with previous findings, but the rate of disease progression, despite treatment, was higher than reported in the literature.

Evaluation of lactate dehydrogenase enzyme activity in saliva and serum of oral submucous fibrosis patients

Of all oral precancerous conditions, Oral Submucous Fibrosis is of greater concern because of its disabling nature and relative greater chances of malignant transformation. This malignant transformation involves glycolytic pathways that can alter lactate dehydrogenase levels. Therefore the aim of this study was to estimate the LDH levels in saliva and serum of subjects with OSMF and to compare them with healthy controls and to correlate the relationship between pathogenesis of OSMF and the LDH enzyme. Sixty Subjects were recruited for this study and divided into two groups, 30 subjects with OSMF (Group A) and 30 healthy controls (Group B). Venous blood and unstimulated whole saliva measuring 1 ml was collected from each of these evaluated for LDH levels using the standard kit method. The data obtained were subjected to statistical analysis using the SPSS software version 17. The average salivary LDH value for Group A was 606.83 ± 60.09 U/l and for Group B was 80.73 ± 20.06 U/l. salivary LDH was greater in group A than Group B and this was statistically significant. On comparing the serum and salivary LDH in Group A with the clinical staging of OSMF, the results were not statistically significant. Similarly no statistically significant relationship was found on comparing the serum and salivary LDH in Group A (OSMF subjects) with duration of habit. This study provides additional rationale for the role of salivary LDH in the early diagnosis and prognosis of oral submucous fibrosis.

An in vitro comparison of a new vinyl chalcogenide and sodium selenate on adenosine deaminase activity of human leukocytes

Selenium (Se) is a dietary essential trace element with important biological roles. Sodium selenate (Na 2SeO 4) is an inorganic Se compound used in human and animal nutrition that acts as precursor for selenoprotein synthesis. The organoselenium 3-methyl-1-phenyl-2-(phenylseleno)oct-2-en-1-one (C 21H 2HOSe) is an α,β-unsaturated ketone functionalized vinyl chalcogenide that has been found as a potential tool in organic synthesis. Adenosine deaminase (ADA) is an important enzyme in the degradation of adenine nucleotides. In this study, we investigated the in vitro effects of both Se compounds on ADA activity and cell viability in leukocyte suspension (LS) of healthy donors ( n = 12). We first observed an inhibition of ADA activity using 0.1 μM of 3-methyl-1-phenyl-2-(phenylseleno)oct-2-en-1-one, and an increase in cellular viability when 30 μM were used. However, we did not observe alterations in the presence of sodium selenate. Moreover, both Se compounds did not alter lactate dehydrogenase activity and thiobarbituric acid reactive substance levels. These results suggest that the inhibition of ADA activity caused by α,β-unsaturated ketone may affect the adenosine levels in LS and modulate cell viability, attenuating conditions that involve the activation of the immune system.

Toxicological evaluation of subchronic exposure to diphenyl diselenide in rats

The aim of this study was to investigate the effects caused by subchronic exposure to diphenyl diselenide in rats. Adult Wistar rats were exposed to diphenyl diselenide (5-300 micromol kg(-1), subcutaneously) once a day for 14 days. The subchronic administration of diphenyl diselenide at a dose of 300 micromol kg(-1) significantly increased aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities in plasma. Conversely, this exposure did not alter lactate dehydrogenase (LDH) activity, urea and creatinine levels in plasma. The activity of delta-aminolevulinate dehydratase (delta-ALA-D) from liver and kidney was inhibited by high dosages of diphenyl diselenide. Diphenyl diselenide did not alter renal Na(+)/K(+)ATPase. A decline in body weight gain was associated with a decrease in food consumption in rats treated with 100 or 300 micromol kg(-1) diphenyl diselenide. At these dosages (100 and 300 micromol kg(-1)), diphenyl diselenide did not cause histological alterations in the liver of rats. Taken together, these results demonstrated that subchronic exposure to diphenyl diselenide at high doses induced minor toxicological effects.

Nitric oxide inhibits heterologous CFTR expression in polarized epithelial cells.

Nitric oxide (. NO) has been implicated in a wide range of autocrine and paracrine signaling mechanisms. Herein, we assessed the role of exogenous. NO in the modulation of heterologous gene expression in polarized kidney epithelial cells (LLC-PK(1)) that were stably transduced with a cDNA encoding human wild-type cystic fibrosis transmembrane conductance regulator (CFTR) under the control of a heavy metal-sensitive metallothionein promoter (LLC-PK(1)-WTCFTR). Exposure of these cells to 125 microM DETA NONOate at 37 degrees C for 24 h (a chemical. NO donor) diminished Zn(2+)-induced and uninduced CFTR protein levels by 43.3 +/- 5.1 and 34.4 +/- 17.1% from their corresponding control values, respectively. These changes did not occur if red blood cells, effective scavengers of. NO, were added to the medium. Exposure to. NO did not alter lactate dehydrogenase release in the medium or the extent of apoptosis. Coculturing LLC-PK(1)-WTCFTR cells with murine fibroblasts that were stably transduced with the human inducible. NO synthase cDNA gene also inhibited CFTR protein expression in a manner that was antagonized by 1 mM N(G)-monomethyl-L-arginine in the medium. Pretreatment of LLC-PK(1)-WTCFTR with ODQ, an inhibitor of guanylyl cyclase, did not affect the ability of. NO to inhibit heterologous CFTR expression; furthermore, 8-bromo-cGMP had no effect on heterologous CFTR expression. These data indicate that. NO impairs the heterologous expression of CFTR in epithelial cells at the protein level via cGMP-independent mechanisms.

Effect of chorionic gonadotropin on lactate dehydrogenase and alcohol dehydrogenase activity in the pathologically altered liver

Chorionic gonadotropin is shown to alter lactate dehydrogenase and alcohol dehydrogenase activity in the pathologically altered liver and to exert a regulatory effect on the catalytic properties of these enzymes.

Response of primary human lung carcinomas to autocrine growth factors produced by a lung carcinoma cell line : Siegfried JM, Owens SE. Carcinogenesis and Metabolism Section, Environmental Health Research and Testing, Inc., Research Triangle Park, NC 27709. Cancer Res 1988;48:4976-81

Medium conditioned for 48 to 72 h by A549-1 lung carcinoma cells was used to culture primary solid lung tumors on feeder layers of inactivated Swiss 3T3 cells. Of 22 cases placed into culture, primary cultures of carcinoma cells were obtained in 20. Subcultures were obtained in 18 cases, and cell lines were established in nine cases. The neoplastic origin of the cultured cells was demonstrated by several criteria: tumorigenicity in athymic mice; anchorage-independent growth; expression of altered lactate dehydrogenase isoenzyme profiles; and expression of the lung tumor marker pregnancy-specific glycoprotein 1. The epithelial nature of cultured carcinoma cells was demonstrated by expression of keratin. These characteristics were compared to normal epithelial cells established in culture from bronchial explants from the same donors as tumor tissue, or other donors. The growth-stimulating effect of conditioned medium toward primary or newly cultured tumor cells was quantitated by clonal assays in soft agar and in monolayer culture. Growth response in clonal assays of newly cultured carcinoma cells to the purified growth factors transforming growth factor alpha and insulin-like growth factor 1, two known components of medium conditioned by A549-1 cells, was also demonstrated.

Factors affecting the lactate dehydrogenase isoenzyme pattern of cultured kidney-cortex cells.

1. The lactate dehydrogenase isoenzyme pattern of cultured calf kidney-cortex cells was correlated to growth phase, changes in oxygen supply, mean generation time and changes in nutritional supply. 2. During culture of free cells and intact explants the lactate dehydrogenase isoenzyme pattern changed towards a dominance of isoenzymes containing the M subunit. 3. Of the shift in monomer proportion, 58% occurred during the lag phase and 42% during the initial part of the exponential growth phase. During the stationary phase the shift in monomer proportion reversed slightly. It was possible to relate the observed shift in monomer proportion to the glycolytic rate. 4. Factors that depressed glycolysis decreased the shift in monomer proportion. Oxygen was found to limit the decrease in the H subunit/M subunit ratio caused by anaerobic culture in vitro. 5. The results obtained support the view that the altered lactate dehydrogenase isoenzyme pattern of urine in renal ischaemia may be explained by anaerobic changes in the lactate dehydrogenase isoenzyme pattern of cortical tubule cells.