[Treatment of winter diseases in summer].

To explore the connotation and essence of treatment of winter diseases in summer with analysis and deduction. Treating winter diseases in summer is the concrete embodiment and application of taking advantage of "recuperating yang in spring and summer". Winter diseases are formed by compound factors with deficiency of yangqi as the prerequisite and yin as well as cold as the predominant pathogens. Its pathological characteristic rests with stagnation in meri-dians and collaterals. Aiming at curing chronic diseases, reinforcing yangqi and removing stagnation in meridians and collaterals, treatment in summer is a treating strategy focused on proper opportunity of treatment, which is expected to yield twice the result with half the effort. To select the suitable indications is taken as the core of this treating strategy. And at the same time, blind expansion without careful consideration is not suggested.

Regulatory role of Arabidopsis pTAC14 in chloroplast development and plastid gene expression.

Transcriptionally active chromosome (TAC) is a fraction of protein/DNA complexes with RNA polymerase activity in the plastid. The function of most TAC proteins is not well known. We isolated a mutant gene encoding a plastid TAC component, pTAC14, and performed functional analysis of plastid gene expression and chloroplast development in Arabidopsis. We found that knockout of pTAC14 led to the blockage of thylakoid formation in the initial process of chloroplast development. Furthermore, the transcript levels of plastid-encoded polymerase (PEP)-dependent genes were downregulated in ptac14, suggesting that PEP activity was decreased in the mutant. On the basis of these results, we briefly review the available evidence and highlight the interaction between pTAC14 and pTAC12 that could help us understand the regulatory role of pTAC14 in chloroplast development and plastid gene expression.

A functional component of the transcriptionally active chromosome complex, Arabidopsis pTAC14, interacts with pTAC12/HEMERA and regulates plastid gene expression.

The SET domain-containing protein, pTAC14, was previously identified as a component of the transcriptionally active chromosome (TAC) complexes. Here, we investigated the function of pTAC14 in the regulation of plastid-encoded bacterial-type RNA polymerase (PEP) activity and chloroplast development. The knockout of pTAC14 led to the blockage of thylakoid formation in Arabidopsis (Arabidopsis thaliana), and ptac14 was seedling lethal. Sequence and transcriptional analysis showed that pTAC14 encodes a specific protein in plants that is located in the chloroplast associated with the thylakoid and that its expression depends on light. In addition, the transcript levels of all investigated PEP-dependent genes were clearly reduced in the ptac14-1 mutants, while the accumulation of nucleus-encoded phage-type RNA polymerase-dependent transcripts was increased, indicating an important role of pTAC14 in maintaining PEP activity. pTAC14 was found to interact with pTAC12/HEMERA, another component of TACs that is involved in phytochrome signaling. The data suggest that pTAC14 is essential for proper chloroplast development, most likely by affecting PEP activity and regulating PEP-dependent plastid gene transcription in Arabidopsis together with pTAC12.

MicroRNA-375 promotes 3T3-L1 adipocyte differentiation through modulation of extracellular signal-regulated kinase signalling.

1. Adipocyte hypertrophy and hyperplasia are important processes in the development of obesity. To understand obesity and its associated diseases, it is important to elucidate the molecular mechanisms governing adipogenesis. MicroRNA-375 has been shown to inhibit differentiation of neurites, and participate in the regulation of insulin secretion and blood homeostasis. However, it is unknown whether miR-375 plays a role in adipocyte differentiation. 2. To investigate the role of miR-375 in adipocyte differentiation, we compared the miR-375 expression level between 3T3-L1 pre-adipocytes and adipocytes using miRNA microarray and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) analysis. Furthermore, we evaluated the effects of overexpression or inhibition of miR-375 on 3T3-L1 adipocyte differentiation. 3. In the present study, we found that miR-375 expression was increased after induction of adipogenic differentiation. Overexpression of miR-375 enhanced 3T3-L1 adipocyte differentiation, as evidenced by its ability to increase mRNA levels of both CCAAT/enhancer binding protein-α (C/EBPα) and peroxisome proliferator-activated receptor-γ (PPARγ2), and induction of adipocyte fatty acid-binding protein (aP2) and triglyceride (TG) accumulation. Furthermore, we found overexpression of miR-375 suppressed phosphorylation levels of extracellular signal-regulated kinases 1/2 (ERK1/2). In contrast, anti-miR-375 increased ERK1/2 phosphorylation levels and inhibited mRNA expression of C/EBPα, PPARγ2 and aP2 in 3T3-L1 adipocyte, accompanied by decreased adipocyte differentiation. 4. Taken together, these data suggest that miR-375 promotes 3T3-L1 adipocyte differentiation, possibly through modulating the ERK-PPARγ2-aP2 pathway.

CHANGES IN microRNA (miR) profile and effects of miR-320 in insulin-resistant 3T3-L1 adipocytes.

1. MicroRNAs (miRNAs) play essential roles in many biological processes. It is known that aberrant miRNA expression contributes to some pathological conditions. However, it is not known whether miRNAs play any role in the development of insulin resistance in adipocytes, a key pathophysiological link between obesity and diabetes. 2. To investigate the function of miRNAs in the development of insulin resistance, using miRNA microarray analysis we compared miRNA expression profiles between normal insulinsensitive 3T3-L1 adipocytes and 3T3-L1 adipocytes rendered insulin resistant following treatment with high glucose (25mmol/L) and high insulin (1 mol/L). Furthermore, adipocytes were transfected with specific antisense oligonucleotides against miRNA-320 (anti-miR-320 oligo) and the effects on the development of insulin resistance were evaluated. 3. We identified 50 upregulated and 29 downregulated miRNAs in insulin-resistant (IR) adipocytes, including a 50-fold increase in miRNA-320 (miR-320) expression. Using bioinformatic techniques, the p85 subunit of phosphatidylinositol 3-kinase (PI3-K) was found to be a potential target of miR-320. In experiments with anti-miR-320 oligo, insulin sensitivity was increased in IR adipocytes, as evidenced by increases in p85 expression, phosphorylation of Akt and the protein expression of the glucose transporter GLUT-4, as well as insulin-stimulated glucose uptake. These beneficial effects of anti-miR-320 oligo were observed only in IR adipocytes and not in normal adipocytes. 4. In conclusion, the miRNA profile changes in IR adipocytes compared with normal 3T3-L1 adipocytes. Anti-miR-320 oligo was found to regulate insulin resistance in adipocytes by improving insulin­PI3-K signalling pathways. The findings provide information regarding a potentially new therapeutic strategy to control insulin resistance.

[Effect of aminoguanidine on hemodynamics and nitrogen monoxide in hemorrhagic shock in rabbit].

OBJECTIVE: To explore the effect of aminoguanidine (AG) on hemodynamics and nitric oxide (NO) in hemorrhagic shock in rabbit. METHODS: Shock was produced in twenty rabbits by femoral artery blood letting, and they were randomly divided into two groups with treatment with saline (control group) or AG (each n=10). Pclab system and nitric acid reductase methods were performed to detect hemodynamics parameters and NO levels at preshock, postshock (30 minutes and 150 minutes) and 30 minutes and 180 minutes after resuscitation respectively. RESULTS: No significant differences were observed in hemodynamics parameters and NO levels between the two groups before resuscitation. Whereas after resuscitation, hemodynamics parameters such as systolic arterial pressure (SAP), heart rate (HR), mean arterial pressure (MAP), left ventricular systolic pressure (LVSP) and the max and minimum first derivative of left ventricular pressure (+/-dp/dt max) were all improved greatly in the two groups. AG decreased serum NO level significantly, while saline did not have such effect, suggesting that AG had a longer and more efficient effect against hemorrhagic shock (P<0.05 or P<0.01). CONCLUSION: AG can improve hemodynamics parameters and decrease NO level in hemorrhagic shock in rabbit.

Heat shock protein 90 acts as a molecular chaperone in late-phase activation of extracellular signal-regulated kinase 1/2 stimulated by oxidative stress in vascular smooth muscle cells.

AIM: To investigate whether cytosolic heat shock protein 90 (HSP90) acts as a molecular chaperone on the activated extracellular signal-regulated kinase 1/2 (ERK1/2) and cell proliferation stimulated by reactive oxygen species (ROS) in rat vascular smooth muscle cells (VSMC). METHODS: VSMC were exposed to 1 micromol/L LY83583 (6-anilinoquinoline-5,8-quinolinedione, producer of ROS) for 120 min in the presence or absence of 5 micromol/L geldanamycin, a specific inhibitor of HSP90. Then the total, soluble, and insoluble proteins of the cells were collected. HSP90, ERK1/2, and phosphor-ERK1/2 in the cell lysate were measured by Western blotting. The interaction of HSP90 and phosphor-ERK1/2 was analyzed by immunoprecipitation assay, and the nuclear phosphor-ERK1/2 was measured by Western blotting and immunofluorescence. Cell proliferation was tested by cell counting and 3-(4,5-dimethylthiazol-2-y1)-3,5-di-phenyltetrazolium bromide (MTT). RESULTS: The cytosolic HSP90 of VSMC was upregulated by LY83583 in a time-dependent manner with the peak at 120 min, which is consistent with the late peak of phosphor-ERK1/2. Immunoprecipitation and Western blotting analyses showed that LY83583 increased the interaction of HSP90 with phosphor-ERK1/2, the phosphor-ERK1/2 level, and the soluble phosphor-ERK1/2 level by 1.8-, 2.5-, and 2.9-fold, respectively. In contrast, the insoluble phosphor-ERK1/2 of VSMC was decreased. Interestingly, LY83583 treatment promoted the nuclear phosphor-ERK1/2 by 7.6-fold as confirmed by Western blotting and immunofluorescence assays. Furthermore, cell counting and the MTT assay showed that LY83583 stimulated VSMC proliferation with the increased expression of HSP90 and levels of soluble and nuclear phosphor-ERK1/2. Pretreatment of geldanamycin antagonized the effect of LY83583. CONCLUSION: HSP90 could mediate the oxidative stress-stimulated, late-phase activation of ERK1/2 and VSMC proliferation by promoting the ERK1/2 phosphorylation, the association of itself with phosphor-ERK1/2, and the solubility and nuclear translocation of phosphor-ERK1/2.