Effect of experimental treatment on GAPDH mRNA expression as a housekeeping gene in human diploid fibroblasts

Diagnostic Performance of a Molecular Assay in Synovial Fluid Targeting Dominant Prosthetic Joint Infection Pathogens

Prosthetic joint infection (PJI) is one of the most serious complications of joint replacement surgery among orthopedic surgeries and occurs in 1 to 2% of primary surgeries. Additionally, the cause of PJIs is mostly bacteria from the Staphylococcus species, accounting for more than 98%, while fungi cause PJIs in only 1 to 2% of cases and can be difficult to manage. The current gold-standard microbiological method of culturing synovial fluid is time-consuming and produces false-negative and -positive results. This study aimed to identify a novel, accurate, and convenient molecular diagnostic method. The DreamDX primer-hydrolysis probe set was designed for the pan-bacterial and pan-fungal detection of DNA from pathogens that cause PJIs. The sensitivity and specificity of DreamDX primer-hydrolysis probes were 88.89% (95% CI, 56.50-99.43%) and 97.62% (95% CI, 87.68-99.88%), respectively, compared with the microbiological method of culturing synovial fluid, and receiver operating characteristic (ROC) area under the curve (AUC) was 0.9974 (*** p < 0.0001). It could be concluded that the DreamDX primer-hydrolysis probes have outstanding potential as a molecular diagnostic method for identifying the causative agents of PJIs, and that host inflammatory markers are useful as adjuvants in the diagnosis of PJIs.

Injectable thermogel incorporating reactive oxygen species scavenger and nitric oxide donor to accelerate the healing process of diabetic wounds

The healing of diabetic wounds is challenging due to redox imbalances. Herein, the thermogelling system AR-ACP hydrogel, with encapsulated biosafe nitric oxide (NO) donor L-arginine and resveratrol as an ROS scavenger, is established for sustainable wound therapy in the diabetic state. The innovated AR-ACP hydrogel dressings shows the sol-gel transition at 34 °C, allowing the hydrogel to fully cover wounds. The combination of L-arginine and resveratrol showed a prominent effect on anti-oxidative activity. The elimination of superoxide anions from the activated immune cells/oxidative cells by resveratrol maintained the NO-proangiogenic factors generated from L-arginine. Furthermore, the AR-ACP hydrogel endowed outstanding features such as haemocompatibility, non-skin irradiation as well as antibacterial activity. In the in vivo diabetic mice model, complete epidermal regeneration comparable to undamaged skin was observed with AR-ACP hydrogel. The synergy between L-arginine and resveratrol in the ACP hydrogel facilitated neovascularisation in the early stage, resulting in the higher balance in cellularity growth and collagen deposition in the dermal layer compared to control groups. Taken together, our findings demonstrate that the use of a customised ACP-based hydrogel, with the additional L-arginine and resveratrol, resulted in significant skin regeneration in the diabetic state.

Identification of Accurate Reference Genes for qRT-PCR Analysis of Gene Expression in Eremochloa ophiuroides under Multiple Stresses of Phosphorus Deficiency and/or Aluminum Toxicity

Centipedegrass (Eremochloa ophiuroides (Munro.) Hack.) is a species originating in China and is an excellent warm-season turfgrass. As a native species in southern China, it is naturally distributed in the phosphorus-deficient and aluminum-toxic acid soil areas. It is important to research the molecular mechanism of centipedegrass responses to phosphorus-deficiency and/or aluminum-toxicity stress. Quantitative Real-Time PCR (qRT-PCR) is a common method for gene expression analysis, and the accuracy of qRT-PCR results depends heavily on the stability of internal reference genes. However, there are still no reported stable and effective reference genes for qRT-PCR analysis of target genes under the acid-soil-related stresses in different organs of centipedegrass. For scientific rigor, the gene used as a reference for any plant species and/or any stress conditions should be first systematically screened and evaluated. This study is the first to provide a group of reliable reference genes to quantify the expression levels of functional genes of Eremochloa ophiuroides under multiple stresses of P deficiency and/or aluminum toxicity. In this study, centipedegrass seedlings of the acid-soil-resistant strain 'E041' and acid-soil-sensitive strain 'E089' were used for qRT-PCR analysis. A total of 11 candidate reference genes (ACT, TUB, GAPDH, TIP41, CACS, HNR, EP, EF1α, EIF4α, PP2A and actin) were detected by qRT-PCR technology, and the stability of candidate genes was evaluated with the combination of four internal stability analysis software programs. The candidate reference genes exhibited differential stability of expression in roots, stems and leaves under phosphorus-deficiency and/or aluminum-toxicity stress. On the whole, the results showed that GAPDH, TIP41 and HNR were the most stable in the total of samples. In addition, for different tissues under various stresses, the selected reference genes were also different. CACS and PP2A were identified as two stable reference genes in roots through all three stress treatments (phosphate deficiency, aluminum toxicity, and the multiple stress treatment of aluminum toxicity and phosphate deficiency). Moreover, CACS was also stable as a reference gene in roots under each treatment (phosphate deficiency, aluminum toxicity, or multiple stresses of aluminum toxicity and phosphate deficiency). In stems under all three stress treatments, GAPDH and EIF4α were the most stable reference genes; for leaves, PP2A and TIP41 showed the two highest rankings in all three stress treatments. Finally, qRT-PCR analysis of the expression patterns of the target gene ALMT1 was performed to verify the selected reference genes. The application of the reference genes identified as internal controls for qRT-PCR analysis will enable accurate analysis of the target gene expression levels and expression patterns in centipedegrass under acid-soil-related stresses.

Comprehensive Analysis of Gene Expression Profiling to Explore Predictive Markers for Eradication Therapy Efficacy against Helicobacter pylori-Negative Gastric MALT Lymphoma

Although radiotherapy is the standard treatment for Helicobacter pylori (Hp)-negative gastric mucosa-associated lymphoid tissue (MALT) lymphoma, eradication therapy using antibiotics and an acid secretion suppressor can sometimes induce complete remission. We explored predictive markers for the response to eradication therapy for gastric MALT lymphoma that were negative for both API2-MALT1 and Hp infection using comprehensive RNA sequence analysis. Among 164 gastric MALT lymphoma patients who underwent eradication therapy as primary treatment, 36 were negative for both the API2-MALT1 fusion gene and Hp infection. Based on eradication therapy efficacy, two groups were established: complete response (CR) and no change (NC). The Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that cancer-related genes and infection-related genes were highly expressed in the NC and CR groups, respectively. Based on this finding and transcription factor, gene ontology enrichment, and protein-protein interaction analyses, we selected 16 candidate genes for predicting eradication therapy efficacy. Real-time PCR validation in 36 Hp-negative patients showed significantly higher expression of olfactomedin-4 (OLFM4) and the Nanog homeobox (NANOG) in the CR and NC groups, respectively. OLFM4 and NANOG could be positive and negative predictive markers, respectively, for eradication therapy efficacy against gastric MALT lymphoma that is negative for both API2-MALT1 and Hp infection.

Fluorescence-Based Detection of Ferrous Iron in Senescent Cells

A major limitation in aging research is the lack of reliable biomarkers to assess phenotypic changes with age or monitor response to antiaging interventions. This study investigates the role of intracellular ferrous iron (Fe₂⁺) as a potential biomarker of senescence. Iron is known to accumulate in various tissues with age and recent studies have demonstrated that its level increases dramatically in senescent cells. The current techniques used to measure the accumulation of iron are cumbersome and only measure total iron not specific isotopes such as the redox reactive Fe₂⁺. It is still to be determined whether the damaging form of iron (Fe₂⁺) is specifically elevated in senescent cells. In this study, we assessed the potential use of a newly discovered Fe₂⁺ reactive probe (SiRhoNox-1) for selective labeling of senescent cells in vitro. For this we have generated various senescent cell models and subjected them to SiRhoNox-1 labeling. Our results indicate that SiRhoNox-1 selectivity labels live senescent cells and was more specific and faster than current staining such as SA-βGal or a derived fluorescent probe C₁₂FDG. Together these findings suggest that SiRhoNox-1 may serve as a convenient tool to detect senescent cells based on their ferrous iron level.

Adipose derived mesenchymal stem cells along with Alpinia oxyphylla extract alleviate mitochondria-mediated cardiac apoptosis in aging models and cardiac function in aging rats

ETHNOPHARMACOLOGICAL RELEVANCE

The Fructus (Alpinia oxyphylla MIQ) known as Yi Zhi Ren in Chinese medicine has been used as a food and herbal medicinal substance in China for centuries; in the year 2015 Chinese Pharmacopoeia Commission reported water extracts of Alpinia oxyphyllae Fructus (AoF) as a popular medication for aging-related diseases in the form of tonic, aphrodisiac, and health-care food in south China.

AIM OF THE STUDY

Adipose mesenchymal stem cells are physiologically and therapeutically associated with healthy vascular function and cardiac health. However aging conditions hinder stem cell function and increases the vulnerability to cardiovascular diseases. In this study, the effect of the anti-aging herbal medicine AoF to enhance the cardiac restorative function of adipose-derived mesenchymal stem cells (ADMSCs) in aging condition was investigated.

MATERIALS AND METHODS

Low dose (0.1 μM) Doxorubicin and D-galactose (150 mg/kg/day for 8 weeks) were used to respectively induce aging in vitro and in vivo. For In vivo studies, 20 week old WKY rats were divided into Control, Aging induced (AI), AI + AoF, AI + ADMSC, AI + AoF Oral + ADMSC, and AI + AoF treated ADMSC groups. AoF (100 mg/kg/day) was administered orally and ADMSCs (1 × 10⁶ cells) were injected (IV).

RESULTS

AoF preconditioned ADMSC showed reduction in low dose Dox induced mitochondrial apoptosis and improved DNA replication in H9c2 cardiomyoblasts. In vivo experiments confirmed that both a combined treatment with AoF-ADMSCs and with AoF preconditioned ADMSCs reduced aging associated cardiac damages which was correlated with reduction in apoptosis and expression of senescence markers (P21 and β-gal). Survival and longevity markers were upregulated up on combined administration of AoF and ADMSCs. The cardiac performance of the aging-induced rats was improved significantly in the treatment groups. AoF along with ADMSCs might activate paracrine factors to restore the performance of an aging heart.

CONCLUSION

Hence, we propose that ADMSCs combined with AoF have promising therapeutic properties in the treatment of healthy aging heart.

Maternal separation in rats induces neurobiological and behavioral changes on the maternal side

The time after parturition is a sensitive period for mothers where they are prone to develop psychopathological symptoms. Studies investigating dams after separation from their pups (maternal separation, MS) showed that MS induces alterations similar to postpartum depression. This study aims to give further details on affected behavior and neurobiology of dams after MS. MS in rats from postnatal day 2-20 over four hours daily was performed. Upon reunion, maternal behavior, and ultrasonic vocalization (USV) of dams were measured. On the day of weaning, dams were tested for anxiety-like behavior in the elevated-plus-maze and marble burying test. Then Morc1 mRNA in the medial prefrontal cortex and Nr3c1 encoding the glucocorticoid receptor mRNA in the hippocampus were measured using real-time PCR to examine possible neurobiological correlates in psychopathology and social behavior. GABA and glutamate serum levels were analyzed by high-performance liquid chromatography as peripheral markers for stress-induced psychopathology. MS in dams increased maternal care towards pups even though both groups show high levels of maternal behavior even in late lactation. Furthermore, the emission of 50-kHz and 22-kHz USVs increased significantly. No differences in anxiety-like behavior were detected. MS further reduced Morc1 but not Nr3c1 expression. Serum GABA but not glutamate levels were significantly increased in separated dams. This study reinforces the benefit of investigating dams after MS for studying postpartum stress. Subclinical markers mainly connected to depression, namely Morc1 and GABA, proved to be useful allowing for earlier detection of symptoms of critical postpartum stress.

Reduction in Filamin C transcript is associated with arrhythmogenic cardiomyopathy in Ashkenazi Jews

BACKGROUND

Filamin C is a cytoskeletal protein expressed in cardiac cells. Nonsense variations in the filamin C gene (FLNC) were associated with dilated and arrhythmogenic cardiomyopathies.

METHODS AND RESULTS

We identified an intronic variation in FLNC gene (c.3791-1G > C) in three unrelated Ashkenazi Jewish families with variable expression of arrhythmia and cardiomyopathy. cDNA was prepared from a mutation carrier's cultured skin fibroblasts. Quantitative PCR demonstrated a reduction in total FLNC transcript, and no other FLNC splice variants were found. Single-nucleotide polymorphism (SNP) analysis revealed heterozygous variations in the genomic DNA that were not expressed in the messenger RNA. Immunohistochemical analysis of cardiac sections detected a normal distribution of filamin C protein in the heart ventricles.

CONCLUSION

The transcript that included the FLNC variant was degraded. Haploinsufficiency in filamin C underlies arrhythmogenic cardiomyopathy with variable symptoms.

In vitro modulation of extracellular matrix genes by stingless bee honey in cellular aging of human dermal fibroblast cells

This study determined the antiaging effect of stingless bee honey on the expression of extracellular matrix genes. MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) assay was performed for determination of optimum concentration and incubation time of stingless bee honey. Gene expression of matrix metalloproteinase-1 (MMP-1) and collagen type Ⅰ (COL1A1) were analyzed using real time reverse transcriptase polymerase chain reaction technique. Incubation with stingless bee honey at concentration of 0.02% for 72 hr showed significant increase in the viability of human fibroblast cells. Stingless bee honey significantly downregulates metalloproteinase-1 gene expression in both pre-senescence and senescence fibroblast cells and upregulates collagen type Ⅰ gene expression in senescence fibroblast cells. In conclusion, stingless bee honey potentially delayed skin aging through modulation of extracellular matrix genes. PRACTICAL APPLICATIONS: Changes of the extracellular matrix regulation promote skin aging. Stingless bee honey is a good source of natural antioxidant which potentially delays skin aging. This study demonstrated that stingless bee honey beneficially increases collagen type Ⅰ expression and decreases MMP-1 expression during cellular aging of human dermal fibroblast cells.

Chlorella vulgaris modulates the expression of senescence-associated genes in replicative senescence of human diploid fibroblasts

Human diploid fibroblasts (HDFs) cultured in vitro have limited capacity to proliferate after population doubling is repeated several times, and they enter into a state known as replicative senescence or cellular senescence. This study aimed to investigate the effect of Chlorella vulgaris on the replicative senescence of HDFs by determining the expression of senescence-associated genes. Young and senescent HDFs were divided into untreated control and C. vulgaris-treated groups. A senescence-associated gene transcription analysis was carried out with qRT-PCR. Treatment of young HDFs with C. vulgaris reduced the expression of SOD1, CAT and CCS (p < 0.05). In addition, the expression of the SOD2 gene was increased with C. vulgaris treatment in young, pre-senescent and senescent HDFs (p < 0.05). Treatment of senescent HDFs with C. vulgaris resulted in the downregulation of TP53 gene expression. The expression of the CDKN2A gene was significantly decreased upon C. vulgaris treatment in young and senescent HDFs. C. vulgaris treatment was also found to significantly upregulate the expression of the MAPK14 gene in pre-senescent HDFs. In addition, the expression of MAPK14 was significantly upregulated compared to that in the untreated senescent HDFs (p < 0.05). In summary, the expression of senescence-associated genes related to antioxidants and the insulin/insulin-like growth factor-1 signalling, DNA damage-associated signalling, cell differentiation and cell proliferation pathways was modulated by C. vulgaris during replicative senescence of human diploid fibroblasts.

Selection of suitable reference genes for gene expression studies in myxosporean (Myxozoa, Cnidaria) parasites

Myxozoans (Cnidaria: Myxozoa) are an extremely diversified group of endoparasites some of which are causative agents of serious diseases in fish. New methods involving gene expression studies have emerged over the last years to better understand and control myxozoan diseases. Quantitative RT-PCR is the most extensively used approach for gene expression studies. However, the accuracy of the results depends on the normalization of the data to reference genes. We studied the expression of eight commonly used reference genes, adenosylhomocysteinase (AHC1), beta actin (ACTB), eukaryotic translation elongation factor 2 (EF2), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), hypoxanthine-guanine phosphoribosyltransferase 1 (HPRT1), DNA-directed RNA polymerase II (RPB2), 18S ribosomal RNA (18S), 28S ribosomal RNA (28S) across different developmental stages of three myxozoan species, Sphaerospora molnari, Myxobolus cerebralis and Ceratonova shasta, representing the three major myxozoan linages from the largest class Myxosporea. The stable reference genes were identified using four algorithms: geNorm, NormFinder, Bestkeeper and ΔCq method. Additionally, we analyzed transcriptomic data from S. molnari proliferative and spore-forming stages to compare the relative amount of expressed transcripts with the most stable reference genes suggested by RT-qPCR. Our results revealed that GAPDH and EF2 are the most uniformly expressed genes across the different developmental stages of the studied myxozoan species.

Determining Influence of Culture Media and Dose-Dependent Supplementation with Basic Fibroblast Growth Factor on the Ex Vivo Proliferative Activity of Domestic Cat Dermal Fibroblasts in Terms of Their Suitability for Cell Banking and Somatic Cell Cloning of Felids

Dermal fibroblasts are commonly used as donors of genetic material for somatic cell nuclear transfer in mammals. Basic fibroblast growth factor (bFGF) is a cytokine that regulates proliferation and differentiation of different cell types. The study was aimed at optimizing the cell culture protocol for cat dermal fibroblasts by assessing the influence of culture media and different doses of bFGF on proliferation of fibroblasts and their viability in terms of cell banking and somatic cloning of felids. In Experiment I, skin biopsies of domestic cats were cultured in DMEM (D) and/or DMEM/F12 (F), both supplemented with 5 ng bFGF/ml (D-5, F-5, respectively). After the primary culture reached ~80% of confluency, the cells were passaged (3–4 times) and cultured in media with (D-5, F-5) or without (D-0, F-0) bFGF. To determine the optimal doses of bFGF, in Experiment II, secondary fibroblasts were cultured in DMEM with 0 (D-0), 2.5 (D-2.5), 5 (D-5) or 10 (D-10) ng bFGF/ml. The results showed that in D-5 the cells proliferated faster than in D-0, F-5 and F-0. Due to their poor proliferation, passages IV were not performed for cells cultured in F-0. In experiment II, a dose-dependent effect of bFGF on proliferation of cat dermal fibroblasts was found. In D-5 and D-10, the cells exhibited higher (P<0.05) proliferation compared with D-0. In D-2.5 the cells showed a tendency to proliferate slower than in D-5 and D-10 and at the same faster than in D-0. In conclusion. DMEM supplemented with bFGF provides better proliferation of domestic cat dermal fibroblasts culture than DMEM/F12. Supplementation of culture medium with bFGF has a beneficial effect on cat dermal fibroblast proliferation and could be recommended for addition to culture media.

Three-Dimensional Printed Polylactic Acid Scaffolds Promote Bone-like Matrix Deposition in Vitro

Large bone defects represent a significant challenge for clinicians and surgeons. Tissue engineering for bone regeneration represents an innovative solution for this dilemma and may yield attractive alternate bone substitutes. Three-dimensional (3D) printing with inexpensive desktop printers shows promise in generating high-resolution structures mimicking native tissues using biocompatible, biodegradable, and cost-effective thermoplastics, which are already FDA-approved for food use, drug delivery, and many medical devices. Microporous 3D-printed polylactic acid scaffolds, with different pore sizes (500, 750, and 1000 μm), were designed and manufactured using an inexpensive desktop 3D printer, and the mechanical properties were assessed. The scaffolds were compared for cell growth, activity, and bone-like tissue formation using primary human osteoblasts. Osteoblasts showed high proliferation, metabolic activity, and osteogenic matrix protein production, in which 750 μm pore-size scaffolds showed superiority. Further experimentation using human mesenchymal stem cells on 750 μm pore scaffolds showed their ability in supporting osteogenic differentiation. These findings suggest that even in the absence of any surface modifications, low-cost 750 μm pore-size 3D-printed scaffolds may be suitable as a bone substitute for repair of large bone defects.

Cytoplasmic delivery of functional siRNA using pH-Responsive nanoscale hydrogels

The progress of short interfering RNA (siRNA) technologies has unlocked the development of novel alternatives for the treatment of a myriad of diseases, including viral infections, autoimmune disorders, or cancer. Nevertheless, the clinical use of these therapies faces significant challenges, mainly overcoming the charged and large nature of these molecules to effectively enter the cell. In this work, we developed a cationic polymer nanoparticle system that is able to load siRNA due to electrostatic interactions. The pH-responsiveness and membrane-disrupting ability of these carriers make them suitable intracellular delivery vehicles. In the work presented herein we synthesized, characterized, and evaluated the properties of nanoparticles based on 2-diethylaminoethyl methacrylate and tert-butyl methacrylate copolymers. A disulfide crosslinker was incorporated in the nanogels to enable the degradation of the nanoparticles in reductive environments, showing no significant changes on their physicochemical properties. The capability of the developed nanogels to be internalized, deliver siRNA, and induce gene knockdown were demonstrated using a human epithelial colorectal adenocarcinoma cell line. Overall, these findings suggest that this platform exhibits desirable characteristics as a potential siRNA-delivery platform.

High expression of acidic chitinase and chitin digestibility in the stomach of common marmoset (Callithrix jacchus), an insectivorous nonhuman primate

Chitin is a polymer of N-acetyl-D-glucosamine (GlcNAc) and a main constituent of insects' exoskeleton. Insects are rich in protein with high energy conversion efficiency. Recently, we have reported that acidic chitinases (Chia) act as digestive enzymes in mouse, pig and chicken (omnivorous) but not in dog (carnivorous) and bovine (herbivorous), indicating that feeding behavior affects Chia expression levels, and determines chitin digestibility in the particular animals. Common marmoset (Callithrix jacchus) belongs to New World monkey family and provides a potential bridge between mouse models and human diseases. Common marmoset is an insectivorous nonhuman primate with unknown expression levels and enzymatic functions of the Chia homologue, CHIA. Here, we report that common marmoset highly expresses pepsin-, trypsin- and chymotrypsin-resistant CHIA in the stomach. We show that CHIA is most active at pH 2.0 and degrades chitin and mealworm shells into GlcNAc dimers under gastrointestinal conditions. Although common marmoset and crab-eating monkey (Old World monkey) have two CHIA genes in their genomes, they primarily express one gene in the stomach. Thus, this study is the first to investigate expression levels and enzymatic functions of CHIA in a New World primate, contributing to the understanding of dietary adaptation and digestion in this taxon.

Molecular Mechanism of Ischaemic Preconditioning of Skeletal Muscle In Vitro

Introduction

Ischaemic preconditioning (IPC) is a phenomenon whereby tissues develop an increased tolerance to ischaemia and subsequent reperfusion if first subjected to sublethal periods of ischaemia. Despite extensive investigation of IPC, the molecular mechanism remains largely unknown. Our aim was to show genetic changes that occur in skeletal muscle cells in response to IPC.

Methods

We established an in vitro model of IPC using a human skeletal muscle cell line. Gene expression of both control and preconditioned cells at various time points was determined. The genes examined were hypoxia-inducible factor-1 alpha (HIF-1 alpha), early growth response 1 (EGR1), JUN, and FOS. HIF-1 alpha is a marker of hypoxia. EGR1, JUN, and FOS are early response genes and may play a role in the protective responses induced by IPC.

Results

HIF-1 alpha was upregulated following one and two hours of simulated ischaemia (p = 0.076 and 0.841, respectively) verifying that hypoxic conditions were met using our model. Expression of EGR1 and FOS was upregulated and peaked after one hour of hypoxia (p = 0.001 and <0.00, respectively). cFOS was upregulated at two and three hours of hypoxia. IPC prior to simulated hypoxia resulted in a greater level of upregulation of EGR1, JUN and FOS genes (p = <0.00, 0.047, and <0.00 respectively).

Conclusion

This study has supported the use of our hypoxic model for studying IPC in vitro. IPC results in a greater upregulation of protective genes in skeletal muscle cells exposed to hypoxia than in control cells. We have demonstrated hitherto unknown molecular mechanisms of IPC in cell culture.

Chitinase mRNA Levels Determined by QPCR in Crab-Eating Monkey (Macaca fascicularis) Tissues: Species-Specific Expression of Acidic Mammalian Chitinase and Chitotriosidase

Mice and humans express two active chitinases: acidic mammalian chitinase (AMCase) and chitotriosidase (CHIT1). Both chitinases are thought to play important roles in specific pathophysiological conditions. The crab-eating monkey (Macaca fascicularis) is one of the most frequently used nonhuman primate models in basic and applied biomedical research. Here, we performed gene expression analysis of two chitinases in normal crab-eating monkey tissues by way of quantitative real-time polymerase chain reaction (qPCR) using a single standard DNA molecule. Levels of AMCase and CHIT1 messenger RNAs (mRNAs) were highest in the stomach and the lung, respectively, when compared to other tissues. Comparative gene expression analysis of mouse, monkey, and human using monkey–mouse–human hybrid standard DNA showed that the AMCase mRNA levels were exceptionally high in mouse and monkey stomachs while very low in the human stomach. As for the CHIT1 mRNA, we detected higher levels in the monkey lung when compared with those of mouse and human. The differences of mRNA expression between the species in the stomach tissues were basically reflecting the levels of the chitinolytic activities. These results indicate that gene expression of AMCase and CHIT1 differs between mammalian species and requiring special attention in handling data in chitinase-related studies in particular organisms.

Selection of reference genes for expression analysis in mouse models of acute alcoholic liver injury

Investigations of hepatic gene expression are crucial for determining the molecular factors involved in acute alcoholic liver injury. The results of liver molecular investigations may reveal etiologically important genomic alterations. Therefore, it is necessary to normalize gene expression data to identify stable genes, which may be used as a reference under different experimental conditions. The aim of the present study was to apply reverse transcription‑quantitative polymerase chain reaction analysis and use analysis software to investigate the expression stability of candidate reference genes in hepatic tissues from mice with acute alcoholic liver injury. The acute alcoholic liver injury models were established by the intragastric administration of alcohol (5 mg/kg) in Imprinting Control Region mice. Total RNA was isolated from the mouse livers, following which the expression levels of seven reference genes, β-actin, glyceraldehyde 3-phosphate dehydrogenase (Gadph), glucuronidase β, hypoxanthine phosphoribosyltransferase 1 (Hprt1), 18S ribosomal RNA, TATA binding protein and β‑2 microglobulin, were examined, and gene expression stability was assessed using the geNorm, NormFinder and BestKeeper tools. The geNorm analysis revealed that the gene with the lowest variability was Hprt1. Hprt1 and Gapdh were validated as the optimal reference gene pair in all samples from all groups. The NormFinder and BestKeeper results showed that Hprt1 was the most stable gene in all samples. Alcohol induces endoplasmic reticulum (ER) stress, causing changes in the expression levels of ER stress‑associated genes. The stability of Hprt1 was verified by the expression analysis of ER stress‑associated genes, and gene expression levels in the ethanol groups were upregulated, with a significant difference in expression, compared with those in the control group. Therefore, Hprt1 was selected as the most stable gene, and Hprt1 and Gapdh were determined to be the optimum gene pair in mouse models of acute alcoholic liver injury. The reliability of the Hprt1 gene was confirmed by expression analysis of ER stress‑associated genes.

Chitin digestibility is dependent on feeding behaviors, which determine acidic chitinase mRNA levels in mammalian and poultry stomachs

Chitin, a polymer of N-acetyl-D-glucosamine (GlcNAc), functions as a major structural component in chitin-containing organism including crustaceans, insects and fungi. Recently, we reported that acidic chitinase (Chia) is highly expressed in mouse, chicken and pig stomach tissues and that it can digest chitin in the respective gastrointestinal tracts (GIT). In this study, we focus on major livestock and domestic animals and show that the levels of Chia mRNA in their stomach tissues are governed by the feeding behavior. Chia mRNA levels were significantly lower in the bovine (herbivores) and dog (carnivores) stomach than those in mouse, pig and chicken (omnivores). Consistent with the mRNA levels, Chia protein was very low in bovine stomach. In addition, the chitinolytic activity of E. coli-expressed bovine and dog Chia enzymes were moderately but significantly lower compared with those of the omnivorous Chia enzymes. Recombinant bovine and dog Chia enzymes can degrade chitin substrates under the artificial GIT conditions. Furthermore, genomes of some herbivorous animals such as rabbit and guinea pig do not contain functional Chia genes. These results indicate that feeding behavior affects Chia expression levels as well as chitinolytic activity of the enzyme, and determines chitin digestibility in the particular animals.

Piper betle L. Modulates Senescence-Associated Genes Expression in Replicative Senescent Human Diploid Fibroblasts

Piper betle (PB) is a traditional medicine that is widely used to treat different diseases around Asian region. The leaf extracts contain various bioactive compounds, which were reported to have antidiabetic, antibacterial, anti-inflammatory, antioxidant, and anticancer effects. In this study, the effect of PB aqueous extracts on replicative senescent human diploid fibroblasts (HDFs) was investigated by determining the expressions of senescence-associated genes using quantitative PCR. Our results showed that PB extracts at 0.4 mg/ml can improve cell proliferation of young (143%), presenescent (127.3%), and senescent (157.3%) HDFs. Increased expressions of PRDX6, TP53, CDKN2A, PAK2, and MAPK14 were observed in senescent HDFs compared to young and/or presenescent HDFs. Treatment with PB extracts modulates the transcriptional profile changes in senescent HDFs. By contrast, expressions of SOD1 increased, whereas GPX1, PRDX6, TP53, CDKN2A, PAK2, and MAPK14 were decreased in PB-treated senescent HDFs compared to untreated senescent HDFs. In conclusion, this study indicates the modulation of PB extracts on senescence-associated genes expression of replicative senescent HDFs. Further studies warrant determining the mechanism of PB in modulating replicative senescence of HDFs through these signaling pathways.

Impaired redox environment modulates cardiogenic and ion-channel gene expression in cardiac-resident and non-resident mesenchymal stem cells

Redox homeostasis plays a crucial role in the regulation of self-renewal and differentiation of stem cells. However, the behavioral actions of mesenchymal stem cells in redox imbalance state remain elusive. In the present study, the effect of redox imbalance that was induced by either hydrogen peroxide (H₂O₂) or ascorbic acid on human cardiac-resident (hC-MSCs) and non-resident (umbilical cord) mesenchymal stem cells (hUC-MSCs) was evaluated. Both cells were sensitive and responsive when exposed to either H₂O₂ or ascorbic acid at a concentration of 400 µmol/L. Ascorbic acid pre-treated cells remarkably ameliorated the reactive oxygen species level when treated with H₂O₂. The endogenous antioxidative enzyme gene (Sod1, Sod2, TRXR1 and Gpx1) expressions were escalated in both MSCs in response to reactive oxygen species elevation. In contrast, ascorbic acid pre-treated hUC-MSCs attenuated considerable anti-oxidative gene (TRXR1 and Gpx1) expressions, but not the hC-MSCs. Similarly, the cardiogenic gene (Nkx 2.5, Gata4, Mlc2a and β-MHC) and ion-channel gene ( I_KDR, I_KCa, I_to and I_Na.TTX) expressions were significantly increased in both MSCs on the oxidative state. On the contrary, reduced environment could not alter the ion-channel gene expression and negatively regulated the cardiogenic gene expressions except for troponin-1 in both cells. In conclusion, redox imbalance potently alters the cardiac-resident and non-resident MSCs stemness, cardiogenic, and ion-channel gene expressions. In comparison with cardiac-resident MSC, non-resident umbilical cord-MSC has great potential to tolerate the redox imbalance and positively respond to cardiac regeneration. Impact statement Human mesenchymal stem cells (h-MSCs) are highly promising candidates for tissue repair in cardiovascular diseases. However, the retention of cells in the infarcted area has been a major challenge due to its poor viability and/or low survival rate after transplantation. The regenerative potential of mesenchymal stem cells (MSCs) repudiate and enter into premature senescence via oxidative stress. Thus, various strategies have been attempted to improve the MSC survival in 'toxic' conditions. Similarly, we investigated the response of cardiac resident MSC (hC-MSCs) and non-resident MSCs against the oxidative stress induced by H₂O₂. Supplementation of ascorbic acid (AA) into MSCs culture profoundly rescued the stem cells from oxidative stress induced by H₂O₂. Our data showed that the pre-treatment of AA is able to inhibit the cell death and thus preserving the viability and differentiation potential of MSCs.

SOCS1 suppresses IL-1β-induced C/EBPβ expression via transcriptional regulation in human chondrocytes

CAAT/enhancer-binding protein-beta (C/EBPβ) is a transcription factor that regulates interleukin-1β (IL-1β)-induced catabolic pathways, including the expression of matrix metalloproteinases (MMPs), in chondrocytes. We previously reported that suppressor of cytokine signaling 1 (SOCS1) inhibits IL-1β signaling in chondrocytes. However, the effect of SOCS1 on C/EBPβ has not been explored. To investigate the interaction between SOCS1 and C/EBPβ, we established human SW1353 cells with overexpression or knockdown of SOCS1 or C/EBPβ. Both SOCS1 and C/EBPβ were involved in transcription of MMP-3 and MMP-13. When stimulated with IL-1β, C/EBPβ levels were significantly increased by SOCS1 knockdown and decreased by SOCS1 overexpression. A similar change in IL-1β-induced C/EBPβ expression was observed in SOCS1-transfected human articular chondrocytes. However, C/EBPβ overexpression or knockdown did not change the levels of IL-1β-induced SOCS1. SOCS1 regulated the levels of C/EBPβ mRNA by ubiquitination of C/EBPβ as well as transcriptional regulation. Furthermore, it suppressed the phosphorylation of cAMP response element-binding protein (CREB), an active transcription factor of C/EBPβ. In addition, p38 mitogen-activated protein kinases, a target of SOCS1, was involved in CREB phosphorylation. The chromatin immunoprecipitation assay confirmed that SOCS1 overexpression led to reduced binding of C/EBPβ to the MMP-13 promoter. Taken together, our results demonstrate that SOCS1 downregulates the p38-CREB-C/EBPβ pathway resulting in increased expression of MMPs in chondrocytes.

Quantitative Real-Time PCR Analysis of YKL-40 and Its Comparison with Mammalian Chitinase mRNAs in Normal Human Tissues Using a Single Standard DNA

YKL-40 (YKL for the first three N-terminal residues of a 40 kDa protein) belongs to a group of human chitinase-like proteins (CLPs), which are similar to chitinases but lack chitinolytic activity. YKL-40 mRNA and its protein levels have been reported elevated in multiple disorders including asthma, cystic fibrosis, rheumatoid arthritis and malignant tumors. Here, we quantified the YKL-40 mRNA levels and compared them with chitinases and housekeeping genes in normal human tissues. To establish the quantitative real-time PCR (qPCR) system for evaluation of relative YKL-40 mRNA levels, we constructed a human standard DNA molecule by ligating cDNAs of YKL-40, two mammalian chitinases and two housekeeping genes in a one-to-one ratio. We generated cDNAs from various normal human tissues and analyzed the YKL-40 mRNA expression levels using a qPCR system with the standard DNA. We found that YKL-40 mRNA is present widely in human tissues while its expression patterns exhibit clear tissue specificity. Highest YKL-40 mRNA levels were detected in the liver, followed by kidney, trachea and lung. The levels of YKL-40 mRNA in the kidney and liver were more than 100-times higher than those of chitotriosidase mRNA. Our study provides for the first time a comprehensive analysis of the relative expression levels of YKL-40 mRNA versus mammalian chitinases in normal human tissues.

Combined ginger extract & Gelam honey modulate Ras/ERK and PI3K/AKT pathway genes in colon cancer HT29 cells

BACKGROUND

The interconnected Ras/ERK and PI3K/AKT pathways play a central role in colorectal tumorigenesis, and they are targets for elucidating mechanisms involved in attempts to induce colon cancer cell death. Both ginger (Zingiber officinale) and honey have been shown to exhibit anti-tumor and anti-inflammation properties against many types of cancer, including colorectal cancer. However, there are currently no reports showing the combined effect of these two dietary compounds in cancer growth inhibition. The aim of this study was to evaluate the synergistic effect of crude ginger extract and Gelam honey in combination as potential cancer chemopreventive agents against the colorectal cancer cell line HT29.

METHODS

The cells were divided into 4 groups: the first group represents HT29 cells without treatment, the second and third groups were cells treated singly with either ginger or Gelam honey, respectively, and the last group represents cells treated with ginger and Gelam honey combined.

RESULTS

The results of MTS assay showed that the IC50 of ginger and Gelam honey alone were 5.2 mg/ml and 80 mg/ml, respectively, whereas the IC50 of the combination treatment was 3 mg/ml of ginger plus 27 mg/ml of Gelam honey with a combination index of < 1, suggesting synergism. Cell death in response to the combined ginger and Gelam honey treatment was associated with the stimulation of early apoptosis (upregulation of caspase 9 and IκB genes) accompanied by downregulation of the KRAS, ERK, AKT, Bcl-xL, NFkB (p65) genes in a synergistic manner.

CONCLUSIONS

In conclusion, the combination of ginger and Gelam honey may be an effective chemopreventive and therapeutic strategy for inducing the death of colon cancer cells.

Establishment of a quantitative PCR system for discriminating chitinase-like proteins: catalytically inactive breast regression protein-39 and Ym1 are constitutive genes in mouse lung

BACKGROUND

Mice and humans produce chitinase-like proteins (CLPs), which are highly homologous to chitinases but lack chitinolytic activity. Mice express primarily three CLPs, including breast regression protein-39 (BRP-39) [chitinase 3-like-1 (Chi3l1) or 38-kDa glycoprotein (gp38k)], Ym1 (Chi3l3) and Ym2 (Chi3l4). Recently, CLPs have attracted considerable attention due to their increased expression in a number of pathological conditions, including asthma, allergies, rheumatoid arthritis and malignant tumors. Although the exact functions of CLPs are largely unknown, the significance of their increased expression levels during pathophysiological states needs to be determined. The quantification of BRP-39, Ym1 and Ym2 is an important step in gaining insight into the in vivo regulation of the CLPs.

METHODS

We constructed a standard DNA for quantitative real-time PCR (qPCR) by containing three CLPs target fragments and five reference genes cDNA in a one-to-one ratio. We evaluated this system by analyzing the eight target cDNA sequences. Tissue cDNAs obtained by reverse transcription from total RNA from four embryonic stages and eight adult tissues were analyzed using the qPCR system with the standard DNA.

RESULTS

We established a qPCR system detecting CLPs and comparing their expression levels with those of five reference genes using the same scale in mouse tissues. We found that BRP-39 and Ym1 were abundant in the mouse lung, whereas Ym2 mRNA was abundant in the stomach, followed by lung. The expression levels of BRP-39 and Ym1 in the mouse lung were higher than those of two active chitinases and were comparable to glyceraldehyde-3-phosphate dehydrogenase, a housekeeping gene which is constitutively expressed in all tissues.

CONCLUSION

Our results indicate that catalytically inactive BRP-39 and Ym1 are constitutive genes in normal mouse lung.

Expression of senescence-associated microRNAs and target genes in cellular aging and modulation by tocotrienol-rich fraction

Emerging evidences highlight the implication of microRNAs as a posttranscriptional regulator in aging. Several senescence-associated microRNAs (SA-miRNAs) are found to be differentially expressed during cellular senescence. However, the role of dietary compounds on SA-miRNAs remains elusive. This study aimed to elucidate the modulatory role of tocotrienol-rich fraction (TRF) on SA-miRNAs (miR-20a, miR-24, miR-34a, miR-106a, and miR-449a) and established target genes of miR-34a (CCND1, CDK4, and SIRT1) during replicative senescence of human diploid fibroblasts (HDFs). Primary cultures of HDFs at young and senescent were incubated with TRF at 0.5 mg/mL. Taqman microRNA assay showed significant upregulation of miR-24 and miR-34a and downregulation of miR-20a and miR-449a in senescent HDFs (P < 0.05). TRF reduced miR-34a expression in senescent HDFs and increased miR-20a expression in young HDFs and increased miR-449a expression in both young and senescent HDFs. Our results also demonstrated that ectopic expression of miR-34a reduced the expression of CDK4 significantly (P < 0.05). TRF inhibited miR-34a expression thus relieved its inhibition on CDK4 gene expression. No significant change was observed on the expression of CCND1, SIRT1, and miR-34a upstream transcriptional regulator, TP53. In conclusion tocotrienol-rich fraction prevented cellular senescence of human diploid fibroblasts via modulation of SA-miRNAs and target genes expression.

Development of an efficient qRT-PCR assay for quality control and cellular quantification of respiratory samples

BACKGROUND

Sample quality is a fundamental parameter for the successful diagnosis of respiratory viruses. This parameter depends upon the concentration of epithelial cells. Respiratory samples are usually heterogeneous, which makes relative quantification of the viral load, against the quantity of cells, the most suitable measurement. The quantification of viral load in the field of respiratory viruses is a vital piece of information. Quantification is required from RNA or DNA viral genomes extracted.

OBJECTIVES

To design (RT-)PCR assays for reference genes, which show stable expression during viral infection, to be used as cellular controls and cellular quantification tools.

STUDY DESIGN

Assays were designed for two reference genes: hypoxanthine phosphoribosyltransferase 1 (HPRT1) and ubiquitin C (UBC). The glyceraldehyde-3-phosphate dehydrogenase gene (GAPDH) was used as a reference for this study. The transcriptional activity of the three genes was studied during infection with respiratory syncytial virus and adenovirus. The HPRT1 q(RT-)PCR assay was used on clinical samples.

RESULTS

All the analysis methods concluded that the three reference genes were stably expressed during viral infection. The HPRT1 q(RT-)PCR assay indicated that the majority of clinical samples (n=301, 69%) had a cellular load of between 100 and 10,000 cells/PCR. The data showed that the concentration decreased as the age of patient increased.

CONCLUSIONS

A new tool has been developed and commercialized for quality control and evaluation of cellular concentration in respiratory samples.

Gelam honey attenuated radiation-induced cell death in human diploid fibroblasts by promoting cell cycle progression and inhibiting apoptosis

Background

The interaction between ionizing radiation and substances in cells will induce the production of free radicals. These free radicals inflict damage to important biomolecules such as chromosomes, proteins and lipids which consequently trigger the expression of genes which are involved in protecting the cells or repair the oxidative damages. Honey has been known for its antioxidant properties and was used in medical and cosmetic products. Currently, research on honey is ongoing and diversifying. The aim of this study was to elucidate the role of Gelam honey as a radioprotector in human diploid fibroblast (HDFs) which were exposed to gamma-rays by determining the expression of genes and proteins involved in cell cycle regulation and cell death.

Methods

Six groups of HDFs were studied viz. untreated control, irradiated HDFs, Gelam honey-treated HDFs and HDF treated with Gelam honey pre-, during- and post-irradiation. HDFs were treated with 6 mg/ml of sterilized Gelam honey (w/v) for 24 h and exposed to 1 Gray (Gy) of gamma-rays at the dose rate of 0.25 Gy/min.

Results

Our findings showed that, gamma-irradiation at 1 Gy up-regulated ATM, p53, p16^ink4a and cyclin D1 genes and subsequently initiated cell cycle arrest at G₀/G₁ phase and induced apoptosis (p < 0.05). Pre-treatment with Gelam honey however caused down regulation of these genes in irradiated HDFs while no significant changes was observed on the expression of GADD45 and PAK genes. The expression of ATM and p16 proteins was increased in irradiated HDFs but the p53 gene was translated into p73 protein which was also increased in irradiated HDFs. Gelam honey treatment however significantly decreased the expression of ATM, p73, and p16 proteins (p < 0.05) while the expression of cyclin D1 remained unchanged. Analysis on cell cycle profile showed that cells progressed to S phase with less percentage of cells in G₀/G₁ phase with Gelam honey treatment while apoptosis was inhibited.

Conclusion

Gelam honey acts a radioprotector against gamma-irradiation by attenuating radiation-induced cell death.

Comparative effects of biodynes, tocotrienol-rich fraction, and tocopherol in enhancing collagen synthesis and inhibiting collagen degradation in stress-induced premature senescence model of human diploid fibroblasts

Biodynes, tocotrienol-rich fraction (TRF), and tocopherol have shown antiaging properties. However, the combined effects of these compounds on skin aging are yet to be investigated. This study aimed to elucidate the skin aging effects of biodynes, TRF, and tocopherol on stress-induced premature senescence (SIPS) model of human diploid fibroblasts (HDFs) by determining the expression of collagen and MMPs at gene and protein levels. Primary HDFs were treated with biodynes, TRF, and tocopherol prior to hydrogen peroxide (H₂O₂) exposure. The expression of COL1A1, COL3A1, MMP1, MMP2, MMP3, and MMP9 genes was determined by qRT-PCR. Type I and type III procollagen proteins were measured by Western blotting while the activities of MMPs were quantified by fluorometric Sensolyte MMP Kit. Our results showed that biodynes, TRF, and tocopherol upregulated collagen genes and downregulated MMP genes (P < 0.05). Type I procollagen and type III procollagen protein levels were significantly increased in response to biodynes, TRF, and tocopherol treatment (P < 0.05) with reduction in MMP-1, MMP-2, MMP-3, and MMP-9 activities (P < 0.05). These findings indicated that biodynes, TRF, and tocopherol effectively enhanced collagen synthesis and inhibited collagen degradation and therefore may protect the skin from aging.

Retropatellar fat pad-derived stem cells from older osteoarthritic patients have lesser differentiation capacity and expression of stemness genes

BACKGROUND AIMS

The use of retropatellar fat pad-derived mesenchymal stromal cells (RFMSCs) for cell-based therapy, particularly for cartilage repair, has been reported by several investigators in recent years. However, the effects of the donor's age and medical condition on the characteristics of RFMSCs have not been well established. The aim of this study was to determine whether age and medical condition can reduce the multipotential of stem cells isolated from the retropatellar fat pad.

METHODS

The RFMSCs were isolated from patients with osteoarthritic knee cartilage (degenerative group; 40-60 years old) and compared with patients without degenerative knee disease (young group; <40 years old) in terms of their growth kinetics, immunophenotype, differentiation ability and stemness gene expression.

RESULTS

Data showed that RFMSCs from both groups have similar growth kinetics and immunophenotype profile at passage 3. However, RFMSCs from the degenerative group showed lower adipogenic, osteogenic and chondrogenic differentiation ability compared with RFMSCs derived from the young group. The stemness gene expression level of RFMSCs derived from the degenerative group was lower than that in the young group. RFMSCs from both groups met the minimum criteria of mesenchymal stromal cells and have the potential for cartilage regeneration. However, RFMSCs from the degenerative group showed lower regeneration capability.

CONCLUSIONS

These results indicate that older age and osteoarthritic condition did affect the multipotential of stem cells derived from the retropatellar fat pad under the current prescribed condition. More studies will be conducted to clarify whether the age or medical condition contributed more to the loss of differentiation capacity and stemness gene expression of RFMSCs.

Inhibition of mitochondrial cytochrome c release and suppression of caspases by gamma-tocotrienol prevent apoptosis and delay aging in stress-induced premature senescence of skin fibroblasts

In this study, we determined the molecular mechanism of γ-tocotrienol (GTT) in preventing cellular aging by focusing on its anti-apoptotic effect in stress-induced premature senescence (SIPS) model of human diploid fibroblasts (HDFs). Results obtained showed that SIPS exhibited senescent-phenotypic characteristic, increased expression of senescence-associated β-galactosidase (SA β-gal) and promoted G₀/G₁ cell cycle arrest accompanied by shortening of telomere length with decreased telomerase activity. Both SIPS and senescent HDFs shared similar apoptotic changes such as increased Annexin V-FITC positive cells, increased cytochrome c release and increased activation of caspase-9 and caspase-3 (P < 0.05). GTT treatment resulted in a significant reduction of Annexin V-FITC positive cells, inhibited cytochrome c release and decreased activation of caspase-9 and caspase-3 (P < 0.05). Gene expression analysis showed that GTT treatment down regulated BAX mRNA, up-regulated BCL2A1 mRNA and decreased the ratio of Bax/Bcl-2 protein expression (P < 0.05) in SIPS. These findings suggested that GTT inhibits apoptosis by modulating the upstream apoptosis cascade, causing the inhibition of cytochrome c release from the mitochondria with concomitant suppression of caspase-9 and caspase-3 activation. In conclusion, GTT delays cellular senescence of human diploid fibroblasts through the inhibition of intrinsic mitochondria-mediated pathway which involved the regulation of pro- and anti-apoptotic genes and proteins.

Reference genes in the developing murine brain and in differentiating embryonic stem cells

OBJECTIVES

Gene expression analysis via quantitative real-time PCR (qPCR) is a key approach in biological and medical research. Here, variations between runs and samples are compensated for by in-parallel analysis of reference genes, which require a most stable expression throughout all samples and experimental procedures to function as internal standards. In reality, there is no universal reference gene; but rather, assumed reference genes vary widely among various cell types. This demands an evaluation of reference genes for each specific experimental purpose, especially in the case of developmental studies. The aim of the present study was to identify suitable reference genes for gene expression analysis in the developing murine brain neocortex in vivo and in mouse embryonic stem cells (mESC) throughout differentiation in vitro.

METHODS

The five candidate genes Actb, 18s, Gapdh, Hprt, and RpII were analyzed throughout development in vivo and in vitro using the quartiles of C(q) values, fold change, coefficient of variation (CV) and the difference between maximum minus twofold standard deviation and mean as the criteria to evaluate their expression stability.

RESULTS

We found that RpII was the most stable expressed gene in mESC throughout differentiation, while in the developing murine neocortex Gapdh showed the highest expression stability.

CONCLUSIONS

Based on our results, we suggest for gene expression analysis in the context of neurodevelopment the usage of RpII as a reference gene for mESC and Gapdh or Hprt for the murine neocortex.

Identification and characterization of genes related to the development of breast muscles in Pekin duck

Pekin Duck is world-famous for its fast growth, but its breast muscle development is later and breast muscle content is lower compared with other muscular ducks. Therefore, it is very important to discover the genetic mechanism between breast muscle development and relative gene expression in Pekin duck. In current study, the genes which have relationships with breast muscle development were identified by suppression subtractive hybridization. A total of 403 positive clones were sequenced and 257 unigenes were obtained. The expression of 23 genes were analyzed in the breast muscle of 2-, 4-, 6-, 8- week old Pekin ducks. The results showed that unknown clone A233, C83 and C99 showed descending tendency as age increased; KBTBD10, HSPA8, MYL1, ZFP622, MARCH4, Nexilin, FABP4 and MUSTN1 had high expression levels at 6 weeks old; WAC, NT5C3, HSP90AA1, MRPL33, KLF6, TSNAX, CDC42EP3, HSPA4, TRAK1, NR2F2, HAUS1 and IGF1 had high expression levels at 8 weeks and showed ascending tendency as age increased. Expression of these 23 genes were also analyzed in breast muscle, leg muscle, heart, kidney, liver, muscular stomach and sebum cutaneum in 4-8-week old Pekin duck and results showed that most of these genes had high expression in breast muscle, leg muscle and heart.

Comparative analysis of expression of human telomerase catalytic subunit at the transcription level in cell cultures of different origin

The expression of human telomerase catalytic subunit in HL-60 and HT-1080 malignant transformed cells and telomerized fibroblasts was studied by quantitative PCR. It was found that the number of transcripts of human telomerase catalytic subunit per cell in telomerized fibroblasts could be hundreds of times higher than in HL-60 and HT-1080 cells. Telomerized fibroblast cultures are suggested as experimental systems for selection of basal compounds for creation of anticancer drug prototypes, the molecular target of which is human telomerase catalytic subunit. The effects of human telomerase catalytic subunit expression on the fibroblast proteome are analyzed.

Gamma-tocotrienol modulation of senescence-associated gene expression prevents cellular aging in human diploid fibroblasts

OBJECTIVE

Human diploid fibroblasts undergo a limited number of cellular divisions in culture and progressively reach a state of irreversible growth arrest, a process termed cellular aging. The beneficial effects of vitamin E in aging have been established, but studies to determine the mechanisms of these effects are ongoing. This study determined the molecular mechanism of γ-tocotrienol, a vitamin E homolog, in the prevention of cellular aging in human diploid fibroblasts using the expression of senescence-associated genes.

METHODS

Primary cultures of young, pre-senescent, and senescent fibroblast cells were incubated with γ-tocotrienol for 24 h. The expression levels of ELN, COL1A1, MMP1, CCND1, RB1, and IL6 genes were determined using the quantitative real-time polymerase chain reaction. Cell cycle profiles were determined using a FACSCalibur Flow Cytometer.

RESULTS

The cell cycle was arrested in the G(0)/G(1) phase, and the percentage of cells in S phase decreased with senescence. CCND1, RB1, MMP1, and IL6 were upregulated in senescent fibroblasts. A similar upregulation was not observed in young cells. Incubation with γ-tocotrienol decreased CCND1 and RB1 expression in senescent fibroblasts, decreased cell populations in the G(0)/G(1) phase and increased cell populations in the G(2)/M phase. γ-Tocotrienol treatment also upregulated ELN and COL1A1 and downregulated MMP1 and IL6 expression in young and senescent fibroblasts.

CONCLUSION

γ-Tocotrienol prevented cellular aging in human diploid fibroblasts, which was indicated by the modulation of the cell cycle profile and senescence-associated gene expression.

Modulation of collagen synthesis and its gene expression in human skin fibroblasts by tocotrienol-rich fraction

INTRODUCTION

Skin aging may occur as a result of increased free radicals in the body. Vitamin E, the major chain-breaking antioxidant, prevents propagation of oxidative stress, especially in biological membranes. In this study, the molecular mechanism of tocotrienol-rich fraction (TRF) in preventing oxidative stress-induced skin aging was evaluated by determining the rate of total collagen synthesis and its gene expression in human skin fibroblasts.

MATERIAL AND METHODS

Primary culture of human skin fibroblasts was derived from circumcision foreskin of 9 to 12 year-old boys. Fibroblast cells were divided into 5 different treatment groups: untreated control, hydrogen peroxide (H(2)O(2))-induced oxidative stress (20 µM H(2)O(2) exposure for 2 weeks), TRF treatment, and pre- and post-treatment of TRF to H(2)O(2)-induced oxidative stress.

RESULTS

Our results showed that H(2)O(2)-induced oxidative stress decreased the rate of total collagen synthesis and down-regulated COL I and COL III in skin fibroblasts. Pre-treatment of TRF protected against H(2)O(2)-induced oxidative stress as shown by increase in total collagen synthesis and up-regulation of COL I and COL III (p<0.05) genes. However, similar protective effects against H(2)O(2)-induced oxidative stress were not observed in the post-treated fibroblasts.

CONCLUSIONS

Tocotrienol-rich fraction protects against H(2)O(2)-induced oxidative stress in human skin fibroblast culture by modulating the expression of COL I and COL III genes with concomitant increase in the rate of total collagen synthesis. These findings may indicate TRF protection against oxidative stress-induced skin aging.

Subcutaneous and intramuscular adipose tissue stearoyl-coenzyme A desaturase gene expression and fatty acid composition in calf- and yearling-fed Angus steers

We proposed that stearoyl-CoA desaturase (SCD) activity dictates fatty acid composition of adipose tissue and muscle in beef cattle, regardless of ruminal or hepatic fatty acid hydrogenation or desaturation. Twelve Angus steers were assigned to a calf-fed (CF) group and slaughtered at weaning (8 mo of age; n=4), 12 mo of age (n=4), or 16 mo of age (n=4). Twelve steers were assigned to a yearling-fed (YF) group and slaughtered at 12 mo of age (n=4), 16 mo of age (n=4), and 17.5 mo of age (n=4; 525 kg, market weight). Data were analyzed based on time on the corn-based finishing diet, with terminal age as a covariate, and orthogonal polynomial contrasts were tested on the main effects of treatment group and time on the finishing diet. Fatty acids from duodenal digesta, plasma, liver, LM, and subcutaneous and intramuscular adipose tissue were measured, and SCD gene expression was measured in intramuscular and subcutaneous adipose tissues. In duodenal digesta, palmitic and linoleic acids increased by 100% over the sampling period, α-linolenic acid decreased over the sampling period, and trans-vaccenic acid was greater in YF than in CF steers (all P < 0.01). The proportion of α-linolenic acid decreased over time in all tissues, including liver. The SCD index (ratio of SCD fatty acid products to SCD fatty acid substrates) increased over time in LM and in intramuscular and subcutaneous adipose tissues. The SCD:glyceraldehyde 3-phosphate dehydrogenase mRNA ratio was virtually undetectable at the initial sampling periods in subcutaneous adipose tissue of YF and CF steers, and it increased over time (P < 0.01). The SCD index and SCD:glyceraldehyde 3-phosphate dehydrogenase ratio were greater in intramuscular adipose tissue of CF steers than in that of YF steers. The SCD index did not change over time in liver and decreased over time in duodenal digesta. We conclude that, unlike essential fatty acids, the SFA and MUFA composition of adipose tissue is regulated by adipose tissue fatty acid desaturation, with little contribution from hepatic or duodenal fatty acids.

In vivo Atoh1 targetome reveals how a proneural transcription factor regulates cerebellar development

The proneural, basic helix-loop-helix transcription factor Atoh1 governs the development of numerous key neuronal subtypes, such as cerebellar granule and brainstem neurons, inner ear hair cells, and several neurons of the proprioceptive system, as well as diverse nonneuronal cell types, such as Merkel cells and intestinal secretory lineages. However, the mere handful of targets that have been identified barely begin to account for Atoh1's astonishing range of functions, which also encompasses seemingly paradoxical activities, such as promoting cell proliferation and medulloblastoma formation in the cerebellum and inducing cell cycle exit and suppressing tumorigenesis in the intestine. We used a multipronged approach to create a comprehensive, unbiased list of over 600 direct Atoh1 target genes in the postnatal cerebellum. We found that Atoh1 binds to a 10 nucleotide motif (AtEAM) to directly regulate genes involved in migration, cell adhesion, metabolism, and other previously unsuspected functions. This study expands current thinking about the transcriptional activities driving neuronal differentiation and provides a framework for further neurodevelopmental studies.