Mycorrhizas alter sucrose and proline metabolism in trifoliate orange exposed to drought stress.

Arbuscular mycorrhizal fungi (AMF) can enhance drought tolerance in plants, whereas little is known regarding AMF contribution to sucrose and proline metabolisms under drought stress (DS). In this study, Funneliformis mosseae and Paraglomus occultum were inoculated into trifoliate orange (Poncirus trifoliata) under well watered and DS. Although the 71-days DS notably (P < 0.05) inhibited mycorrhizal colonization, AMF seedlings showed significantly (P < 0.05) higher plant growth performance and leaf relative water content, regardless of soil water status. AMF inoculation significantly (P < 0.05) increased leaf sucrose, glucose and fructose concentration under DS, accompanied with a significant increase of leaf sucrose phosphate synthase, neutral invertase, and net activity of sucrose-metabolized enzymes and a decrease in leaf acid invertase and sucrose synthase activity. AMF inoculation produced no change in leaf ornithine-δ-aminotransferase activity, but significantly (P < 0.05) increased leaf proline dehydrogenase activity and significantly (P < 0.05) decreased leaf both Δ1-pyrroline-5-carboxylate reductase and Δ1-pyrroline-5-carboxylate synthetase activity, resulting in lower proline accumulation in AMF plants under DS. Our results therefore suggest that AMF strongly altered leaf sucrose and proline metabolism through regulating sucrose- and proline-metabolized enzyme activities, which is important for osmotic adjustment of the host plant.

Mycorrhizal trifoliate orange has greater root adaptation of morphology and phytohormones in response to drought stress.

Plant roots are the first parts of plants to face drought stress (DS), and thus root modification is important for plants to adapt to drought. We hypothesized that the roots of arbuscular mycorrhizal (AM) plants exhibit better adaptation in terms of morphology and phytohormones under DS. Trifoliate orange seedlings inoculated with Diversispora versiformis were subjected to well-watered (WW) and DS conditions for 6 weeks. AM seedlings exhibited better growth performance and significantly greater number of 1st, 2nd, and 3rd order lateral roots, root length, area, average diameter, volume, tips, forks, and crossings than non-AM seedlings under both WW and DS conditions. AM fungal inoculation considerably increased root hair density under both WW and DS and root hair length under DS, while dramatically decreased root hair length under WW but there was no change in root hair diameter. AM plants had greater concentrations of indole-3-acetic acid, methyl jasmonate, nitric oxide, and calmodulin in roots, which were significantly correlated with changes in root morphology. These results support the hypothesis that AM plants show superior adaptation in root morphology under DS that is potentially associated with indole-3-acetic acid, methyl jasmonate, nitric oxide, and calmodulin levels.

Acetylated a-tubulin sense the change of extracellular matrix to regulate the invasion and metastasis of breast cancer / 中国医师杂志

Objective To reveal acetylated a-tubulin acts as pressure sensors,sensing the changes in extracellular matrix to impact on the invasion and metastasis of breast cancer.Methods The acetylated alpha microtubule protein expressions were detected,and its relationship with invasion and metastasis in breast cancer clinical specimens and different molecular subtypes of breast cancer cell lines were analyzed.The expression of acetylated a-tubulin was interfered through chemical methods,and cell morphology and the change of the invasion and metastasis ability were detected under the condition of different matrix hardness.Results The expression of acetylated a-tubulin was highest in basal-like breast cancer tissue and cell lines,and was lowest expressed in the luminal B breast cancer tissue and the breast cancer cell lines.The expression of acetylated a-microtubule was positively correlated with the occurrence of breast cancer.Under the condition of soft substrate cultivation,cell polarization was declined,becoming the circular or oval shape.The acetylated a-tubulin caused reduction in cell polarity,accompanied with less invasion and metastasis ability.Conclusions The acetylated a-tubulin acts as pressure sensors,sensing the sclerosis of extracellular matrix in the process of tumorigenesis,promoting invasion and metastasis of breast cancer.

Cep70 drives taxol drug resistance through regulating the acetylation α-tubulin to reduce microtubule stability / 中国医师杂志

Objective To explore the Cep70 by adjusting the stability of acetylated alpha tubulin,participate in breast cancer drug resistance mechanisms.Methods (1) In order to induce taxol drug resistance cell line Michigan cancer foundation-7 (MCF-7)/pac,high-dose shock treatments taxol MCF-7 was used for 6 months,until the cells can grow in 3.5 μmol/L of paclitaxel.(2) The 3-(4,5-dimenthylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) method was used to detect inhibition rate by taxol to MCF-7 and MCF-7/pac cell.(3) Immunofluorescence and Western blot were used to test acetylated alpha-tubulin and Cep70 expression levels in MCF-7 and MCF-7/pac cells.(4) Chemical intervention was used to acetylate apha-tubulin expression,Western blot and polymerase chain reaction (PCR) were used to detect the change of acetylated alpha-tubulin and Cep70 in MCF-7 and MCF-7/pac groups.Flow cytometry and Western blot were used to detect the change of cell cycle.Results (1) IC50 of MCF-7 and MCF-7/pac was 22.47 μ mol/L and 31.38 μmol/L,respectively.(2) Immunofluorescence and Western blot results showed that the expression of acetylation of alpha-tubulin in resistant MCF-7 cell/pac was obviously decreased.(3) Real time polymerase chain reaction (RT-PCR) and Western blot showed Cep70 expression was consistent of acetylation of alpha-tubulin.(4) After incubation with paclitaxel for 24 hours,the expressions of acetylation of alpha-tubulin and Cep70 in MCF-7 and MCF-7/pac were increased,but the extent of MCF-7 cell was much higher.Instead,incubation with nocodazole after 24 hours,the acetylation of alpha-tubulin and Cep70 in MCF-7 and MCF-7/pac cells were obviously lowered.(5) After paclitaxel intervention,compared to the same group MCF-7 cells,the G2 phase ratio in MCF-7/pac cells was lower.In addition,given nocodazole after the intervention,compared to the same group MCF-7 cells,the ratio of G2 phase in MCF-7 cell/pac was significantly decreased.Conclusions Cep70 decreased the expression of the acetylated alpha-tubulin,reduced the stability of microtubules,which could be an important mechanism of taxol drug resistance.

The role of endoplasmic reticulum stress in the formation of fatty liver in high-fat diet fed mice / 中国医师杂志

Objective To explore the influence of endoplasmic reticulum stress on fatty liver in mice feeding with high-fat diet.Methods The 8-week-old male C57BL/6J mice were randomly divided into two groups:high-fat diet group (with 60％ calories by high saturated fatty acid) and control group (with chow diet),both groups had been fed for 16 weeks.H&E-staining and Sudan Ⅳ-staining reflected lipid deposition in liver.The levels of 78-kDa glucose-regulated protein (GRP78),protein kinase R-like endoplasmic reticulum kinase (PERK),phosphorylated α subunit of eukaryotic initiation factor 2 (p-eIF1 α),C/EBP homologous protein (CHOP),steroid regulated element binding proteins 1 (SREBP-1),and fatty acid synthetase (FAS) protein were determined by Western blot to reflect the endoplasmic reticulum stress and lipid synthesis.Results In liver of high fat diet (HFD) group,H&E staining showed that the cytoplasm of hepatocytes were filled with vacuoles,Sudan Ⅳ staining also displayed that many different sizes of red lipid drops exist in hepatocytes.Compared to the liver of control group,high-fat diet induced endoplasmic reticulum stress and elevated lipid synthesis,as evidenced by increases in the level of peroxisome proliferator-activated receptor alpha (PPARα) mRNA expression,and the protein levels of GRP78,PERK,phosphorylated eIF2α,CHOP were also significantly increased.In primary normal hepatocytes incubated with exogenous oleic acid intervention for 24-72 hours,the expression of GRP78,PERK,phosphorylated eIF2α,CHOP protein levels,and the expression of SREBP-1 and FAS protein were significantly increased in dose-dependent manner.Conclusions Feeding with high-fat diet led to accumulation of lipid deposition in liver and fatty liver,the underlying mechanisms might be related to induction of endoplasmic reticulum stress.

Experimental study on immatural dendritic cells infected by HIV-1 pseudovirus / 中国免疫学杂志

Objective:To construct HIV-1 pseudovirus containing enhanced green fluorescent protein ( EGFP ) gene. To understand the interaction between the virus and the cells. Methods: HIV-1 pseudovirus containing EGFP gene was constructed by lentiviral packaging systems, and its EGFP gene was amplified using RT-PCR. The level of genomic integration and transcription of HIV-1 pseudovirus containing EGFP gene were detected on iDCs infected with HIV-1 pseudovirus. At the same time, research on expression of the EGFP gene in iDCs infected with HIV-1 pseudovirus was performed. Results:The EGFP gene of HIV-1 pseudovirus was detected through RT-PCR. The EGFP gene was identified in iDCs infected with HIV-1 pseudovirus through PCR and RT-PCR. The EGFP was observed in iDCs infected with HIV-1 pseudovirus under fluorescence microscopy. Conclusion: HIV-1 pseudovirus containing EGFP gene has been successfully produced. The HIV-1 pseudovirus that we constructed can infect iDCs,then its RNA can integrate into the genome of iDCs in the way of reverse transcription,and the EGFP gene could express in the iDCs after infected with HIV-1 pseudovirus.

Experimental study on immatural dendritic cells infected by HIV-1 pseudovirus / 中国免疫学杂志

Objective:To construct HIV-1 pseudovirus containing enhanced green fluorescent protein ( EGFP ) gene. To understand the interaction between the virus and the cells. Methods: HIV-1 pseudovirus containing EGFP gene was constructed by lentiviral packaging systems, and its EGFP gene was amplified using RT-PCR. The level of genomic integration and transcription of HIV-1 pseudovirus containing EGFP gene were detected on iDCs infected with HIV-1 pseudovirus. At the same time, research on expression of the EGFP gene in iDCs infected with HIV-1 pseudovirus was performed. Results:The EGFP gene of HIV-1 pseudovirus was detected through RT-PCR. The EGFP gene was identified in iDCs infected with HIV-1 pseudovirus through PCR and RT-PCR. The EGFP was observed in iDCs infected with HIV-1 pseudovirus under fluorescence microscopy. Conclusion: HIV-1 pseudovirus containing EGFP gene has been successfully produced. The HIV-1 pseudovirus that we constructed can infect iDCs,then its RNA can integrate into the genome of iDCs in the way of reverse transcription,and the EGFP gene could express in the iDCs after infected with HIV-1 pseudovirus.

SRGN enhances the breast cancer cells metastasis by inducing Epithelial-mesenchymal transition / 中国医师杂志

Objective To investigate the mechanism of glycoprotein serglycin (SRGN) promoting metastasis of breast cancer cells and the possible mechanism of SRGN expression.Methods Real time quantitative polymerase chain reaction (PCR) and bioinformation retrieval were used to detect the expression of SRGN in lymph node metastasis and non-metastasis breast cancer.MDA-MB-231 shRNA and MCF-7-SRGN of breast cancer stable cell line were established by lentivirus shRNA interferencc and overexpression.Transwell assay was used to test the effect of SRGN on invasion and metastasis of breast cancer cell line in vitro.Western blot assay was used to detect the changes of epithelial-mesenchymal (EMT) related markers.The possible regulatory mechanism of SRGN expression was detected by Western blot assay.Results SRGN expression was significantly increased in lymph node metastasis of breast cancer in clinical specimens.SRGN interference inhibited the invasion and metastasis of tumor cells.SRGN promoted breast cancer cells EMT.Transforming growth factor β1 (TGFβ1) promoted the expression of beta SRGN transcription.Conclusions SRGN can induce the change of EMT in breast cancer cells and promote the invasion and metastasis of breast cancer cells.

Effect of insulin resistance on fatty liver in high-fat diet-fed mice / 中国病理生理杂志

[ ABSTRACT] AIM:To study the influence of insulin resistance on fatty liver in the mice fed with high-fat diet (HFD).METHODS:Male 8-week-old C57BL/6J mice were randomly divided into HFD group (with 60% calories by high saturated fatty acid) and control group (with chow diet).The mice in both groups were fed for 12 weeks.The body weight, liver weight, serum triglyceride (TG) and total cholesterol (TC), and blood glucose and insulin levels were meas-ured.Hyperinsulinemic euglycemic clamp experiment was applied to reflect insulin sensitivity .The lipid deposition in the liver was analyzed by HE staining , Sudan IV staining and measurement of liver fat content .The phosphorylation levels of IRS1 and Akt, and the protein levels of SREBP-1 and FAS were determined by Western blot to reflect the activities of insu-lin signaling and lipid synthesis .RESULTS:Compared with control group , the body weight and liver weight were signifi-cantly increased in HFD group .TG and TC contents in serum and liver tissues were remarkably increased in HFD group . High-fat diet induced insulin resistance , as evidenced by increased serum insulin levels , reduced glucose infusion rate and decreases in IRS1 and Akt phosphorylation levels .In livers of HFD group, HE staining showed that the cytoplasm of hepa-tocytes was filled with vacuoles .Sudan IV staining also displayed that many different sizes of red lipid drops existed in the hepatocytes , and the protein levels of SREBP-1 and FAS were significantly increased .In primary normal hepatocytes with exogenous oleic acid intervention for 48 h, the phosphorylation levels of IRS 1 and Akt were reduced , and the protein ex-pression of SREBP-1 and FAS was significantly increased in a dose-dependent manner .CONCLUSION: Feeding with HFD leads to insulin resistance , resulting in activation of lipid synthesis and accumulation of lipid deposition in the liver , thus inducing fatty liver .

Endogenous nitric oxide synthase inhibitor increase skeletal muscle con-tractility and mitochondria biosynthesis in 4-week running rats / 中国病理生理杂志

[ ABSTRACT] AIM:To observe the effect of endogenous nitric oxide synthase ( NOS) inhibitor asymmetric dimeth-ylarginine ( ADMA ) and its signaling pathways on NO levels and skeletal muscle contractility in 4-week running rats. METHODS:The 4 weeks running rat model was established.The twitch tension, tetanic tension and the fatigue test of sole-us muscle induced by electrical stimulation ex vivo were detected.The ATP content, mitochondrial DNA levels and the mR-NA expression of peroxisome proliferator-activated receptor γcoactivator-1α(PGC-1α), nuclear respiratory factor (NRF) were measured to reflect the mitochondrial function and biosynthesis in the skeletal muscle.Serum ADMA concentration was detected by high performance liquid chromatography.The endogenous ADMA enzymes PRMT1 and 2 subtypes of ADMA me-tabolism enzyme DDAH, 3 subtypes of NOS protein expression in the skeletal muscle were determined by Western blot.NOS activity and nitric oxide ( NO) content were analyzed by colorimetric method.RESULTS: Compared with normal control group, the twitch tension, tetanic tension and the anti-fatigue capability of soleus muscle in running group were significantly enhanced, ATP content, mitochondrial DNA content and the mRNA expression of PGC-1αand NRF were significantly in-creased (P ance of soleus muscle.The mechanism may be that increased cNOS expression feedbacks to increase ADMA concentration, thus maintaining the increase in NO synthesis at a relatively low level, and resulting in promoting skeletal muscle mitochon-dria biosynthesis and mitochondrial function.

Disruption of mycorrhizal extraradical mycelium and changes in leaf water status and soil aggregate stability in rootbox-grown trifoliate orange.

Arbuscular mycorrhizas possess well developed extraradical mycelium (ERM) network that enlarge the surrounding soil for better acquisition of water and nutrients, besides soil aggregation. Distinction in ERM functioning was studied under a rootbox system, which consisted of root+hyphae and root-free hyphae compartments separated by 37-µm nylon mesh with an air gap. Trifoliate orange (Poncirus trifoliata) seedlings were inoculated with Funneliformis mosseae in root+hyphae compartment, and the ERM network was established between the two compartments. The ERM network of air gap was disrupted before 8 h of the harvest (one time disruption) or multiple disruptions during seedlings acclimation. Our results showed that mycorrhizal inoculation induced a significant increase in growth (plant height, stem diameter, and leaf, stem, and root biomass) and physiological characters (leaf relative water content, leaf water potential, and transpiration rate), irrespective of ERM status. Easily-extractable glomalin-related soil protein (EE-GRSP) and total GRSP (T-GRSP) concentration and mean weight diameter (MWD, an indicator of soil aggregate stability) were significantly higher in mycorrhizosphere of root+hyphae and root-free hyphae compartments than non-mycorrhizosphere. One time disruption of ERM network did not influence plant growth and soil properties but only notably decreased leaf water. Periodical disruption of ERM network at weekly interval markedly inhibited the mycorrhizal roles on plant growth, leaf water, GRSP production, and MWD in root+hyphae and hyphae chambers. EE-GRSP was the most responsive GRSP fraction to changes in leaf water and MWD under root+hyphae and hyphae conditions. It suggests that effect of peridical disruption of ERM network was more impactful than one-time disruption of ERM network with regard to leaf water, plant growth, and aggregate stability responses, thereby, implying ERM network aided in developing the host plant metabolically more active.

Effects of calorie restriction for 8 weeks on contractile function and mito-chondrial biosynthesis in different types of rat skeletal muscles / 中国病理生理杂志

AIM:To investigate the influence of calorie restriction ( CR) on contractility and mitochondrial bi-osynthesis in different types of rat skeletal muscles .METHODS:CR rat model was set up by feeding 60%normal food in-take of control rat every day for 8 weeks.Soleus (SOL) and extensor digitorum longus (EDL) were isolated under anesthe-sia.The twitch tension, titanic tension and fatigue resistance of SOL and EDL in response to electrical stimulation were measured to reflect the contractile function of the muscles .The copy number ratio of mitochondrial gene cytochrome C oxi-dase subunit I ( COX I) to nuclear gene β-actin was determined to evaluate the mitochondrial biosynthesis .ATP content was measured to mirror mitochondrial function .RESULTS:Compared with control group , CR for 8 weeks significantly in-creased twitch tension and titanic tension of both SOL and EDL , but only improved fatigue resistance in SOL .Markedly in-crease in ATP content in both skeletal muscles by CR intervention was observed , especially in SOL .Although CR activated AMP-activated protein kinase (AMPK) in both 2 muscles, up-regulation of mitochondrial biosynthesis and transcription of mitochondrial regulatory genes peroxisome proliferator-activated receptor γcoactivator 1α( PGC-1α) and nuclear respirato-ry factor ( NRF) was only observed in SOL .CONCLUSION:CR for 8 weeks enhanced the contractility of both rat SOL and EDL in response to electrical stimulation , especially in SOL composed of slow-twitch fibers.The mechanisms may be related to the activation of AMPK and the promotion of mitochondrial biosynthesis in SOL .

Effects and mechanisms of endurance exercise for 8 weeks on contractile function and mitochondrial biogenesis in rat skeletal muscles / 中国药理学通报

Aim This study was aimed to explore the influence and mechanism of the long-term exercise on skeletal muscle contraction and mitochondrial biosyn-thesis in different muscle fibers.Methods Soleus (SOL)and extensor digitorum longus (EDL)were i-solated from SD male rats with platform running train-ing for eight weeks.The changes of contractility under different electrical stimulation were observed, mito-chondrial biosynthesis,including ATP content,mito-chondrial DNA,the gene expression of PGC-1αand NRF were also detected.Results Long-term endur-ance exercise can improve twitch tension and titanic tension of SOL and EDL ,but only enhanced the fa-tigue resistance in SOL.ATP contents were significant-ly increased in the two types of muscles,but mtDNA content,PGC-1αexpression and NRF translation were only obviously enhanced in SOL,in accompanied with an increase in p-AMPK/AMPK protein ratio.Conclu-sion Long-term endurance exercise increased skeletal muscle contractility and improved the anti-fatigue abili-ty in SOL,which may be associated with increase in mitochondrial biosynthesis via activated AMPK-PGC-1αaxis.

Mycorrhizal-induced calmodulin mediated changes in antioxidant enzymes and growth response of drought-stressed trifoliate orange.

Trifoliate orange [Poncirus trifoliata (L) Raf.] is considered highly arbuscular mycorrhizal (AM) dependent for growth responses through a series of signal transductions in form of various physiological responses. The proposed study was carried out to evaluate the effect of an AM fungus (Funneliformis mosseae) on growth, antioxidant enzyme (catalase, CAT; superoxide dismutase, SOD) activities, leaf relative water content (RWC), calmodulin (CaM), superoxide anion ([Formula: see text]), and hydrogen peroxide (H2O2) concentrations in leaves of the plants exposed to both well-watered (WW) and drought stress (DS) conditions. A 58-day of DS significantly decreased mycorrhizal colonization by 60% than WW. Compared to non-AM seedlings, AM seedlings displayed significantly higher shoot morphological properties (plant height, stem diameter, and leaf number), biomass production (shoot and root fresh weight) and leaf RWC, regardless of soil water status. AM inoculation significantly increased CaM and soluble protein concentrations and CAT activity, whereas significantly decreased [Formula: see text] and H2O2 concentration under both WW and DS conditions. The AM seedlings also exhibited significantly higher Cu/Zn-SOD and Mn-SOD activities than the non-AM seedlings under DS but not under WW, which are triggered by higher CaM levels in AM plants on the basis of correlation studies. Further, the negative correlation of Cu/Zn-SOD and Mn-SOD activities with [Formula: see text] and H2O2 concentration showed the DS-induced ROS scavenging ability of CaM mediated SODs under mycorrhization. Our results demonstrated that AM-inoculation elevated the synthesis of CaM in leaves and up-regulated activities of the antioxidant enzymes, thereby, repairing the possible oxidative damage to plants by lowering the ROS accumulation under DS condition.

Mycorrhizal-mediated lower proline accumulation in Poncirus trifoliata under water deficit derives from the integration of inhibition of proline synthesis with increase of proline degradation.

Proline accumulation was often correlated with drought tolerance of plants infected by arbuscular mycorrhizal fungi (AMF), whereas lower proline in some AM plants including citrus was also found under drought stress and the relevant mechanisms have not been fully elaborated. In this study proline accumulation and activity of key enzymes relative to proline biosynthesis (▵(1)-pyrroline-5-carboxylate synthetase, P5CS; ornithine-δ-aminotransferase, OAT) and degradation (proline dehydrogenase, ProDH) were determined in trifoliate orange (Poncirus trifoliata, a widely used citrus rootstock) inoculated with or without Funneliformis mosseae and under well-watered (WW) or water deficit (WD). AMF colonization significantly increased plant height, stem diameter, leaf number, root volume, biomass production of both leaves and roots and leaf relative water content, irrespectively of water status. Water deficit induced more tissue proline accumulation, in company with an increase of P5CS activity, but a decrease of OAT and ProDH activity, no matter whether under AM or no-AM. Compared with no-AM treatment, AM treatment resulted in lower proline concentration and content in leaf, root, and total plant under both WW and WD. The AMF colonization significantly decreased the activity of both P5CS and OAT in leaf, root, and total plant under WW and WD, except for an insignificant difference of root OAT under WD. The AMF inoculation also generally increased tissue ProDH activity under WW and WD. Plant proline content significantly positively correlated with plant P5CS activity, negatively with plant ProDH activity, but not with plant OAT activity. These results suggest that AM plants may suffer less from WD, thereby inducing lower proline accumulation, which derives from the integration of an inhibition of proline synthesis with an enhancement of proline degradation.

High concentration of tacrolimus inhibits proliferation and osteoblastic differentiation of human mesenchymal stem cells / 中国药理学与毒理学杂志

OBJECTIVE To investigate the effect of tacrolimus on cell proliferation and osteoblastic differentiation of primary human bone marrow-derived mesenchymal stem cells (hBMSCs). METHODS hBMSCs were cultured with tacrolimus 0.001-5 μmol·L-1. BrdU incorporation was used to assess the cell proliferation while cellular alkaline phosphatase (ALP) activity and calcium deposition were measured to evaluate the osteoblastic differentiation of hBMSCs cultures. The calcineurin (CaN) activity was also examined using commercial CaN assay kit, and core binding factor 1 alpha subunit (Cbfα1) protein level was determined by Western blotting. RESULTSTacrolimus 0.001-0.1 μmol·L-1 promoted BrdU incorporation but had no effect on ALP activity and calcium deposition, whereas tacrolimus 0.5-5 μmol·L-1 resulted in significant decrease in both cell proliferation and osteoblastic maturation, by reducing BrdU incorporation, ALP activity, and calcium deposition of hBMSCs cultures in a concentration-dependent manner. In addition, tacrolimus 0.5-5 μmol·L-1 led to concentration-dependent decrement in CaN activity, which was consistent with down-regulated Cbfα1 protein in the tacrolimus treated cells. CONCLUSION High concentration of tacrolimus might inhibit the cell proliferation and osteoblastic differentiation of hBMSCs cultures through a CaN/Cbfα1 pathway.

[Experimental analysis of microRNAs related to cardiac development differential expression].

OBJECTIVE: To investigate the differential expression profiles of microRNAs in the knockout Pax-8 mice by miRNA microarray analysis and study the function of microRNA during cardiac development. METHODS: The knockout Pax-8 mice model was established and the total RNA derived from Pax-8 KO-/- and Pax-8 KO+/- mice heart. MicroRNA microarray containing 567 mammalian microRNA probes was used to investigate the microRNAs differential expression between Pax-8 KO-/- and Pax-8 KO+/- mice. The candidates of microRNAs were confirmed by real time RT-PCR assay. RESULTS: The heart of pax-8 KO-/- mice became spheroidal. Left ventricle enlargement, left ventricular wall and interventricular septum thickening and papillary muscles in left ventricle enlargement were found. Furthermore, many apoptotic cells were discovered in left ventricular wall and interventricular septum in pax-8 KO-/- mice. The MicroRNA microarray result displayed 10 microRNAs differential expressions, in which 2 microRNAs became down-regulated and 8 microRNAs up-regulated by more than two folds in pax-8 KO-/- mice. This was in accordance with the result of real-time RT-PCR. CONCLUSION: Some microRNAs may play important roles in cardiac development and ventricular septal defect pathogenesis.