An analysis of expression patterns of genes encoding proteins with catalytic activities

Glucose Supplementation Improves Performance and Alters Glucose Transporters' Expression in Pectoralis major of Heat-Stressed Chickens

Glucose level in birds' tissue decreases due to heat stress (HS)-induced reduction in feed intake (FI); impairing metabolism and growth. The effect of glucose supplementation on the performance of broiler chickens was evaluated under thermoneutral (TN) and HS conditions. Glucose was supplemented at 0 and 6% under TN-(25 °C) and HS-(25 °C-35 °C-25 °C) conditions. The treatments were TN + 0%-glucose (TN0); TN + 6%-glucose (TN6), HS + 0%-glucose (HS0) and HS + 6%-glucose (HS6). There were 6 replicates (19 birds each)/treatment. Heat and glucose supplementation were applied from d28-35. At d35, Pectoralis (P.) major was sampled from one bird/replicate to determine glucose transporters' mRNA expression. Heat application lowered (p < 0.05) FI, body weight gain, and increased feed and water conversion ratios. Glucose supplementation increased total energy intake by 4.9 and 3.2% in TN and HS groups, respectively but reduced FI under TN and HS conditions. The P. major- and drumstick-yield reduced (p < 0.05) in HS0 compared to TN0, TN6 and HS6. Under HS, glucose supplementation improved eviscerated carcass weight by 9% and P. major yield by 14%. Glucose supplementation increased SGLT1 expression with/without heat treatment while HS independently increased the expression of GLUT 1, 5 and 10. Glucose supplementation under HS could improve performance of broilers.

Tip60 might be a candidate for the acetylation of hepatic carbonic anhydrase I and III in mice

BACKGROUND

Carbonic anhydrases (CAs) play a significant role in maintaining pH balance by catalyzing the conversion of carbon dioxide to bicarbonate. The regulation of pH is critical for all living organisms. Although there are many studies in the literature on the biochemical, functional, and structural features of CAs, there is not sufficient information about the epigenetic regulation of CAs.

METHODS AND RESULTS

The lysine acetyltransferase TIP60 (60 kDa Tat-interactive protein) was knocked out specifically in mouse liver using the Cre/loxP system, and knockout rate was shown as 83-88% by Southern blot analysis. The impact of Tip60 on the expression of Ca1, Ca3, and Ca7 was investigated at six Zeitgeber time (ZT) points in the control and liver-specific Tip60 knockout mice (mutant) groups by real-time PCR. In the control group, while Ca1 showed the highest expression at ZT8 and ZT12, the lowest expression profile was observed at ZT0 and ZT20. Hepatic Ca1 displayed robust circadian expression. However, hepatic Ca3 exhibited almost the same level of expression at all ZT points. The highest expression of Ca7 was observed at ZT12, and the lowest expression was determined at ZT4. Furthermore, hepatic Ca7 also showed robust circadian expression. The expression of Ca1 and Ca3 significantly decreased in mutant mice at all time periods, but the expression of Ca7 used as a negative control was not affected.

CONCLUSIONS

It was suggested for the first time that Tip60 might be considered a candidate protein in the regulation of the Ca1 and Ca3 genes, possibly by acetylation.

Proteomic profile differentiating between mesial temporal lobe epilepsy with and without hippocampal sclerosis

Hippocampal sclerosis (HS) is the most common neuropathological condition in adults with drug-resistant epilepsy and represents a critical feature in mesial temporal lobe epilepsy (MTLE) syndrome. Although epileptogenic brain tissue is associated with glutamate excitotoxicity leading to oxidative stress, the proteins that are targets of oxidative damage remain to be determined. In the present study we designed comprehensive analyses of changes in protein expression level and protein oxidation status in the hippocampus or neocortex to highlight proteins associated with excitotoxicity by comparing MTLE patients with relatively mild excitotoxicity (MTLE patients without HS, MTLE-non-HS) and those with severe excitotoxicity (MTLE patients with HS, MTLE-HS). We performed 2-dimensional fluorescence difference gel electrophoresis, 2D-oxyblot analysis, and mass spectrometric amino acid sequencing. We identified 16 proteins at 18 spots in which the protein expression levels differed between sclerotic and non-sclerotic hippocampi. In the sclerotic hippocampus, the expression levels of several synaptic proteins were decreased, and those of some glia-associated proteins increased. We confirmed histologically that all MTLE-HS cases examined exhibited severe neuronal cell loss and remarkable astrocytic gliosis in the hippocampi. In all MTLE-non-HS cases examined, neurons were spared and gliosis was unremarkable. Therefore, we consider that decreased synaptic proteins are a manifestation of loss of neuronal cell bodies and dendrites, whereas increased glia-associated proteins are a manifestation of proliferation and hypertrophy of astrocytes. These are considered to be the result of hippocampal sclerosis. In contrast, the expression level of d-3-phosphoglycerate dehydrogenase (PHGDH), an l-serine synthetic enzyme expressed exclusively by astrocytes, was decreased, and that of stathmin 1, a neurite extension-related protein expressed by neurons, was increased in the sclerotic hippocampus. These findings cannot be explained solely as the result of hippocampal sclerosis. Rather, these changes can be involved in the continuation of seizure disorders in MTLE-HS. In addition, the protein carbonylation detection, an indicator of protein oxidation caused by excitotoxicity of multiple seizures and/or status epilepticus, revealed that the carbonyl level of collapsin response mediator protein 2 (CRMP2) increased significantly in the sclerotic hippocampus. In conclusion, protein identification following profiling of protein expression levels and detection of oxidative proteins indicated potential pathognomonic protein changes. The decreased expression of PHGDH, increased expression of stathmin 1, and carbonylation of CRMP2 differentiate between MTLE with and without HS. Therefore, further investigations of PHGDH, stathmin 1 and CRMP2 are promising to study more detailed effects of excitotoxicity on epileptogenic hippocampal tissue.

Glucose Metabolism and Dynamics of Facilitative Glucose Transporters (GLUTs) under the Influence of Heat Stress in Dairy Cattle

Heat stress is one of the main threats to dairy cow production; in order to resist heat stress, the animal exhibits a variety of physiological and hormonal responses driven by complex molecular mechanisms. Heat-stressed cows have high insulin activity, decreased non-esterified fatty acids, and increased glucose disposal. Glucose, as one of the important biochemical components of the energetic metabolism, is affected at multiple levels by the reciprocal changes in hormonal secretion and adipose metabolism under the influence of heat stress in dairy cattle. Therefore, alterations in glucose metabolism have negative consequences for the animal’s health, production, and reproduction under heat stress. Lactose is a major sugar of milk which is affected by the reshuffle of the whole-body energetic metabolism during heat stress, contributing towards milk production losses. Glucose homeostasis is maintained in the body by one of the glucose transporters’ family called facilitative glucose transporters (GLUTs encoded by SLC2A genes). Besides the glucose level, the GLUTs expression level is also significantly changed under the influence of heat stress. This review aims to describe the effect of heat stress on systemic glucose metabolism, facilitative glucose transporters, and its consequences on health and milk production.

Effects of Decreasing Dietary Crude Protein Level on Growth Performance, Nutrient Digestion, Serum Metabolites, and Nitrogen Utilization in Growing Goat Kids (Capra hircus)

Simple Summary

Reducing the dietary protein content could potentially reduce losses of nitrogen from ruminant farms and mitigate pressure on the protein ingredient supply. However, there is little information in the literature on the effect of low-protein diets in growing Anhui white goat kids. We demonstrated that decreasing the dietary crude protein level in Anhui white goat kids affected growth performance, improved nitrogen utilization, and reduced environmental nitrogen pollution. The key finding of this study was that a diet containing 13.4% crude protein supplied adequate protein to improve nitrogen utilization in white goat kids without any adverse effect on growth performance.

Abstract

The effects of decreasing dietary crude protein (CP) level on growth performance, nutrient digestion, serum metabolites, and nitrogen utilization in growing goat kids were investigated in the current study. Thirty-six male Anhui white goat kids were randomly assigned to one of three CP content diets: 14.8% (control), 13.4%, and 12.0% of dry matter, respectively. Diets were isoenergetic. The experiment lasted for 14 weeks, with the first two weeks being for adaptation. Results showed that the low-CP diet decreased average daily gain, feed efficiency, digestibility of dry matter, organic matter, crude protein, and fiber. No significant changes were observed in dry-matter intake. With a decrease in dietary CP level, fecal nitrogen excretion (% of nitrogen intake) increased linearly, whereas CP intake, blood urea nitrogen, urinary nitrogen excretion (% of nitrogen intake), and total nitrogen excretion (% of nitrogen intake) decreased. Serum glucose concentration decreased, while concentrations of low-density lipoproteins and non-esterified fatty acids increased with the low-CP diet. In conclusion, decreasing the dietary CP level decreased goats’ nitrogen excretion, but with restrictive effects on growth performance. A diet containing 13.4% CP is optimal for reducing nitrogen excretion without any adverse effect on growth performance of Anhui white goat kids. This concentration is 1.4% points lower than the NRC recommendations and thus is also environmentally beneficial on the input side because it decreases the use of feed (soy) protein.

Phenotypic variability in deficiency of the α subunit of succinate-CoA ligase

Succinyl-CoA synthetase or succinate-CoA ligase deficiency can result from biallelic mutations in SUCLG1 gene that encodes for the alpha subunit of the succinyl-CoA synthetase. Mutations in this gene were initially associated with fatal infantile lactic acidosis. We describe an individual with a novel biallelic pathogenic mutation in SUCLG1 with a less severe phenotype dominated by behavioral problems. The mutation was identified to be c.512A>G corresponding to a p.Asn171Ser change in the protein. The liquid chromatography tandem mass spectrometry-based enzyme activity assay on cultured fibroblasts revealed a markedly reduced activity of succinyl-CoA synthetase enzyme when both ATP and GTP were substrates, affecting both ADP-forming and GDP-forming functions of the enzyme.

Spatiotemporal Analysis of a Glycolytic Activity Gradient Linked to Mouse Embryo Mesoderm Development

How metabolism is rewired during embryonic development is still largely unknown, as it remains a major technical challenge to resolve metabolic activities or metabolite levels with spatiotemporal resolution. Here, we investigated metabolic changes during development of organogenesis-stage mouse embryos, focusing on the presomitic mesoderm (PSM). We measured glycolytic labeling kinetics from ¹³C-glucose tracing experiments and detected elevated glycolysis in the posterior, more undifferentiated PSM. We found evidence that the spatial metabolic differences are functionally relevant during PSM development. To enable real-time quantification of a glycolytic metabolite with spatiotemporal resolution, we generated a pyruvate FRET-sensor reporter mouse line. We revealed dynamic changes in cytosolic pyruvate levels as cells transit toward a more anterior PSM state. Combined, our approach identifies a gradient of glycolytic activity across the PSM, and we provide evidence that these spatiotemporal metabolic changes are intrinsically linked to PSM development and differentiation.

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Identification of glycolytic activity gradient in mouse presomitic mesoderm

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Development of a pyruvate FRET-reporter mouse model

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Real-time imaging reveals pyruvate gradient dynamics

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Metabolic state is linked to presomitic mesoderm cell differentiation

A class of sulfonamides as carbonic anhydrase I and II inhibitors

Four groups of novel sulfonamide derivatives: (i) acetoxybenzamide, (ii) triacetoxybenzamide, (iii) hydroxybenzamide and (iv) trihydroxybenzamide, all having thiazole, pyrimidine, pyridine, isoxazole and thiadiazole moieties were prepared and their inhibitory effects were studied on two metalloenzymes, i.e. carbonic anhydrase isozymes (hCA I and II), purified from human erythrocyte cells by Sepharose-4B-l-tyrosine-sulfanilamide affinity chromatography. These enzymes are present in almost all living organisms to catalyse the synthesis of bicarbonate ion (HCO₃^-) from carbon dioxide and water. The sulfonamide derivatives were found to be active against hCA I and II in the range of 2.62-136.54 and 5.74-210.58 nM, respectively.

Synthesis and inhibitory properties of some carbamates on carbonic anhydrase and acetylcholine esterase

A series of carbamate derivatives were synthesized and their carbonic anhydrase I and II isoenzymes and acetylcholinesterase enzyme (AChE) inhibitory effects were investigated. All carbamates were synthesized from the corresponding carboxylic acids via the Curtius reactions of the acids with diphenyl phosphoryl azide followed by addition of benzyl alcohol. The carbamates were determined to be very good inhibitors against for AChE and hCA I, and II isoenzymes. AChE inhibition was determined in the range 0.209-0.291 nM. On the other hand, tacrine, which is used in the treatment of Alzheimer's disease possessed lower inhibition effect (Ki: 0.398 nM). Also, hCA I and II isoenzymes were effectively inhibited by the carbamates, with inhibition constants (Ki) in the range of 4.49-5.61 nM for hCA I, and 4.94-7.66 nM for hCA II, respectively. Acetazolamide, which was clinically used carbonic anhydrase (CA) inhibitor demonstrated Ki values of 281.33 nM for hCA I and 9.07 nM for hCA II. The results clearly showed that AChE and both CA isoenzymes were effectively inhibited by carbamates at the low nanomolar levels.

A compendium of expression patterns of cholesterol biosynthetic enzymes in the mouse embryo

Cholesterol and its biosynthetic pathway intermediates and derivatives are required for many developmental processes including membrane biogenesis, transmembrane receptor signaling, steroid biogenesis, nuclear receptor activation, and posttranslational modification of hedgehog (Hh) proteins. To perform such multifaceted tasks depends on stringent regulation of expression of cholesterol biosynthetic enzymes (CBEs). We established for a whole organism, for the first time, the 3D expression pattern of all genes required for cholesterol biosynthesis (CBS), starting from acetyl-CoA and ending with cholesterol. This data was produced by high-throughput in situ hybridization on serial sections through the mouse fetus. The textually annotated image data were seamlessly integrated into the METscout and GenePaint public databases. This novel information helps in the understanding of why CBEs are expressed at particular locations within the fetus. For example, strong CBE expression is detected at sites of cell proliferation and also where cell growth increases membrane surface, such as in neurons sprouting axons and forming synapses. The CBE data also sheds light on the spatial relationship of cells and tissue that express sonic Hh (Shh) and produce cholesterol, respectively. We discovered that not all cells expressing Shh are capable of CBS. This finding suggests novel ways by which cholesterylation of Shh is regulated.

N-Acylsulfonamides strongly inhibit human carbonic anhydrase isoenzymes I and II

Sulfonamides represent a significant class of biologically active compounds that inhibit carbonic anhydrase (CA, EC.: 4.2.1.1) isoenzymes involved in different pathological and physiological events. Sulfonamide CA inhibitors are used therapeutically as diuretic, antiglaucoma, antiobesity and anticancer agents. A series of new sulfonamides were synthesized using imides and tosyl chloride as starting materials. These N-acylsulfonamides efficiently inhibited the cytosolic human carbonic anhydrase isoenzymes I, and II (hCA I, and II), with nanomolar range inhibition constants ranging between 36.4 ± 6.0-254.6 ± 18.0 and 58.3 ± 0.6-273.3 ± 2.5 nM, respectively.

Goose fat, a promising nutrient for fish feeding, activates antioxidant enzymes in rainbow trout, Oncorhynchus mykiss

The objective of this experiment was to test effects of different dietary lipids in rainbow trout feeding on the activity and expression of antioxidant enzymes, superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione S-transferase (GST). Four iso-nitrogenous and iso-lipidic casein-gelatin based experimental diets were formulated. The sources of dietary lipids were cod liver oil (CO, rich in polyunsaturated fatty acids), goose fat (GF, rich in saturated fatty acids and monounsaturated fatty acids), soybean oil (SO, rich in linoleic acid), and a blend of CO, GF and SO. Dietary treatments had no significant effect on growth performance and survival was not affected. SOD, GPx and GST enzymes had the maximum activity in GF diet. However qPCR data showed that SOD and GPx mRNA levels were minimum in GF group. Overall data showed that rainbow trout liver enzymes were activated upon GF diet probably activating the enzyme structure itself without stimulating gene expression.

A genome-wide screen indicates correlation between differentiation and expression of metabolism related genes

Differentiated tissues may be considered as materials with distinct properties. The differentiation program of a given tissue ensures that it acquires material properties commensurate with its function. It may be hypothesized that some of these properties are acquired through production of tissue-specific metabolites synthesized by metabolic enzymes. To establish correlation between metabolism and organogenesis we have carried out a genome-wide expression study of metabolism related genes by RNA in-situ hybridization. 23% of the metabolism related genes studied are expressed in a tissue-restricted but not tissue-exclusive manner. We have conducted the screen on whole mount chicken (Gallus gallus) embryos from four distinct developmental stages to correlate dynamic changes in expression patterns of metabolic enzymes with spatio-temporally unique developmental events. Our data strongly suggests that unique combinations of metabolism related genes, and not specific metabolic pathways, are upregulated during differentiation. Further, expression of metabolism related genes in well established signaling centers that regulate different aspects of morphogenesis indicates developmental roles of some of the metabolism related genes. The database of tissue-restricted expression patterns of metabolism related genes, generated in this study, should serve as a resource for systematic identification of these genes with tissue-specific functions during development. Finally, comprehensive understanding of differentiation is not possible unless the downstream genes of a differentiation cascade are identified. We propose, metabolic enzymes constitute a significant portion of these downstream target genes. Thus our study should help elucidate different aspects of tissue differentiation.

OGDHL is a modifier of AKT-dependent signaling and NF-κB function

Oxoglutarate dehydrogenase (OGDH) is the first and rate-limiting component of the multi-enzyme OGDH complex (OGDHC) whose malfunction is associated with neuro-degeneration. The essential role of this complex is in the degradation of glucose and glutamate and the OGDHL gene (one component of OGDHC) is down-regulated by promoter hypermethylation in many different cancer types. These properties suggest a potential growth modulating role of OGDHL in cancer; however, the molecular mechanism through which OGDHL exerts its growth modulating function has not been elucidated.

Here, we report that restoration of OGDHL expression in cervical cancer cells lacking endogenous OGDHL expression suppressed cell proliferation, invasion and soft agar colony formation in vitro. Knockdown of OGDHL expression in cervical cancer cells expressing endogenous OGDHL had the opposite effect. Forced expression of OGDHL increased the production of reactive oxygen species (ROS) leading to apoptosis through caspase 3 mediated down-regulation of the AKT signaling cascade and decreased NF-κB phosphorylation. Conversely, silencing OGDHL stimulated the signaling pathway via increased AKT phosphorylation. Moreover, the addition of caspase 3 or ROS inhibitors in the presence of OGDHL increased AKT signaling and cervical cancer cell proliferation.

Taken together, these data suggest that inactivation of OGDHL can contribute to cervical tumorigenesis via activation of the AKT signaling pathway and thus support it as an important anti-proliferative gene in cervical cancer.

Purification and characterization of carbonic anhydrase from the teleost fish Dicentrarchus labrax (European seabass) liver and toxicological effects of metals on enzyme activity

Carbonic anhydrase (EC 4.2.1.1; CA) was purified and characterized from the liver of the teleost fish Dicentrarchus labrax (European seabass) for the first time. The purification procedure consisted of a single step affinity chromatography on Sepharose 4B-tyrosine-sulfanilamide. The enzyme was purified 78.8-fold with a yield of 46%, and a specific activity of 751.72U/mg proteins. It has an optimum pH at 7.5; an optimum temperature at 25°C; an optimum ionic strength at 10mM and a stable pH at 8.5. The kinetic parameters of this enzyme were determined for its esterase activity, with 4-nitrophenyl acetate (NPA) as substrate and the purified enzyme had an apparent K(M) and V(max) values of 0.44 mM and 0.249 μmolxmin(-1), respectively. The following metals, Al(+3), Cu(+2), Pb(+2), Co(+3), Ag(+1), Zn(+2) and Hg(+2) showed inhibitory effects on the enzyme. Al(+3) and Cu(+2) exhibited the strongest inhibitory action. Pb(+2) was moderate inhibitor, whereas other metals showed weaker actions. All tested metals inhibited the enzyme in a competitive manner. Our findings indicate that these metals inhibit the fish enzyme in a similar manner to other α-CAs from mammals investigated earlier, but the susceptibility to various metals differ between the fish and mammalian enzymes. Our results also demonstrate that these metals might be dangerous at low micromolar concentrations for fish CA enzymes.

Gluconeogenesis in dairy cows: the secret of making sweet milk from sour dough

Gluconeogenesis is a crucial process to support glucose homeostasis when nutritional supply with glucose is insufficient. Because ingested carbohydrates are efficiently fermented to short-chain fatty acids in the rumen, ruminants are required to meet the largest part of their glucose demand by de novo genesis after weaning. The qualitative difference to nonruminant species is that propionate originating from ruminal metabolism is the major substrate for gluconeogenesis. Disposal of propionate into gluconeogenesis via propionyl-CoA carboxylase, methylmalonyl-CoA mutase, and the cytosolic form of phosphoenolpyruvate carboxykinase (PEPCK) has a high metabolic priority and continues even if glucose is exogenously supplied. Gluconeogenesis is regulated at the transcriptional and several posttranscriptional levels and is under hormonal control (primarily insulin, glucagon, and growth hormone). Transcriptional regulation is relevant for regulating precursor entry into gluconeogenesis (propionate, alanine and other amino acids, lactate, and glycerol). Promoters of the bovine pyruvate carboxylase (PC) and PEPCK genes are directly controlled by metabolic products. The final steps decisive for glucose release (fructose 1,6-bisphosphatase and glucose 6-phosphatase) appear to be highly dependent on posttranscriptional regulation according to actual glucose status. Glucogenic precursor entry, together with hepatic glycogen dynamics, is mostly sufficient to meet the needs for hepatic glucose output except in high-producing dairy cows during the transition from the dry period to peak lactation. Lactating cows adapt to the increased glucose requirement for lactose production by mobilization of endogenous glucogenic substrates and increased hepatic PC expression. If these adaptations fail, lipid metabolism may be altered leading to fatty liver and ketosis. Increasing feed intake and provision of glucogenic precursors from the diet are important to ameliorate these disturbances. An improved understanding of the complex mechanisms underlying gluconeogenesis may further improve our options to enhance the postpartum health status of dairy cows.

Synthesis and carbonic anhydrase inhibitory properties of novel bromophenols including natural products

(2-Bromo-3,4-dimethoxyphenyl) (3,4-dimethoxyphenyl)methanone (10) and its derivatives with Br, one dibromide and isomeric three tribromides, were synthesized. Demethylation of these compounds afforded a series of new bromophenols. Inhibition of human cytosolic carbonic anhydrase II (hCA II) isozyme by these new bromophenols and naturally occurring 3,4,6-tribromo-5-(2,5-dibromo-3,4-dihydroxybenzyl)benzene-1,2-diol (3), and 5,5'-methylenebis(3,4,6-tribromo-benzene-1,2-diol) (4) was investigated. The synthesized compounds showed carbonic anhydrase inhibitory capacities with IC(50) values in the range of 0.7-372 μM against hCA II. Some bromophenols investigated here showed effective hCA II inhibitory activity and might be used as leads for generating novel carbonic anhydrase inhibitors which are valuable drug candidates for the treatment of glaucoma, epilepsy, gastric and duodenal ulcers, neurological disorders, or osteoporosis.

In Vitro inhibition of human carbonic anhydrase I and II isozymes with natural phenolic compounds

Inhibition of two human cytosolic carbonic anhydrase (hCA, EC 4.2.1.1) isozymes I and II with some natural phenolic derivatives was investigated using the esterase assay with 4-nitrophenyl acetate as substrate. Resveratrol, catechin, silymarin, dobutamin, and curcumin showed K(I) values in the range of 4.47-9.47 mm for hCA I and of 2.86-7.44 μm against hCA II, respectively. These natural product phenols were generally competitive inhibitors with 4-nitrophenylacetate as substrate. Some natural phenols investigated here showed effective hCA II inhibitory effects, in the same range as the clinically used sulfonamide acetazolamide, and might be used as leads for generating enzyme inhibitors possibly targeting other CA isoforms that have not been yet assayed for their interactions with such agents.

Lysyl oxidase-like 3b is critical for cartilage maturation during zebrafish craniofacial development

Vertebrate craniofacial development requires coordinated morphogenetic interactions between the extracellular matrix (ECM) and the differentiating chondrocytes essential for cartilage formation. Recent studies reveal a critical role for specific lysyl oxidases in ECM integrity required for embryonic development. We now demonstrate that loxl3b is abundantly expressed within the head mesenchyme of the zebrafish and is critically important for maturation of neural crest derived cartilage elements. Histological and ultrastructural analyses of cartilage elements in loxl3b morphant embryos reveal abnormal maturation of cartilage and altered chondrocyte morphology. Spatiotemporal analysis of craniofacial markers in loxl3b morphant embryos shows that cranial neural crest cells migrate normally into the developing pharyngeal arches but that differentiation and condensation markers are aberrantly expressed. We further show that the loxl3b morphant phenotype is not due to P53 mediated cell death but likely to be due to reduced chondrogenic progenitor cell proliferation within the pharyngeal arches. Taken together, these data demonstrate a novel role for loxl3b in the maturation of craniofacial cartilage and can provide new insight into the specific genetic factors important in the pathogenesis of craniofacial birth defects.

Up-regulation of Idh3alpha causes reduction of neuronal differentiation in PC12 cells

The PC12 is the widely used cell line to study neuronal differentiation. We had extensively investigated the details of protein expression in differentiated PC12 cells by proteomic analysis. The cells were incubated at the presence of nerve growth factor. We had analyzed the expression changes in the differentiating PC12 cells by 2-dimensional electrophoresis and the identification of the proteins using MALDI-TOF MS. By comparing expression pattern in the time course, we identified the candidate genes which are associated with neuronal differentiation. Among these genes, we performed real-time PCR analysis to validate Idh3alpha expression by the time course. To identify the function of Idh3alpha in neuronal differentiation stage, the transfection of Idh3alpha to PC12 cells was performed. As a result, we proved that up-regulation of Idh3alpha causes reduction in neural differentiation of PC12 cells. Based on these data, we suggest that Idh3alpha plays a role to the neuronal differentiation.