Inhibition of tumor suppressor p53 preserves glycation-serum induced pancreatic beta-cell demise

Tumor suppressor p53 is a transcriptional factor that determines cell fate in response to multiple stressors, such as oxidative stress and endoplasmic reticulum stress, in the majority of cells. However, its role in pancreatic beta cells is not well documented. Our previous research has revealed that glycation-serum (GS) induced pancreatic beta-cell demise through the AGEs-RAGE pathway. In the present study, we investigated the role of p53 in GS-related beta-cell demise. Using pancreatic islets beta-cell line INS-1 cells, we found that with GS treatment, the transcriptional activity of p53 was significantly evoked due to the increased amount of nuclear p53 protein. Resveratrol (RSV) was capable of further enhancing this transcriptional ability and consequently increased the population of dead beta cells under GS exposure. In contrast, inhibiting this transcriptional activity via p53 interference greatly protected beta cells from the damage provoked by GS, as well as damage strengthened by RSV. However, the pharmacological activation of PPARγ with troglitazone (TRO) only suppressed GS-induced, not RSV-induced, p53 activity. Moreover, the activation of PPARγ greatly preserved beta cells from GS-induced death. This protective effect recurred due to improved mitochondrial function with Bcl2 overexpression. Further, p53 activation could induce cellular apoptosis in primary rat islets. Our findings explore the broader role of p53 in regulating pancreatic beta-cell demise in the presence of GS and may provide a therapeutic target for the treatment and prevention of diabetes.

Cross-cultural translation of the Lysholm knee score in Chinese and its validation in patients with anterior cruciate ligament injury

Background

The Lysholm Knee Score (LKS) is widely used and is one of the most effective questionnaires employed to assess knee injuries. Although LKS has been translated into multiple languages, there is no Chinese version even though China has the largest population of patients with knee-joint injuries. The objective of our study was to develop the Chinese version of LKS (C-LKS) and assess its reliability, validity and responsiveness in Chinese patients with anterior cruciate ligament (ACL) injuries.

Methods

Study participants were mainly recruited among patients with ACL injuries scheduled for arthroscopic ACL reconstruction at our hospital. First, we developed the C-LKS in a five-step translation and cross-cultural adaptation procedure. Next, we calculated the Cronbach’s alpha, intraclass correlation coefficient (ICC), Pearson’s correlation coefficient (r), effect size (ES), and standardized response mean (SRM) to evaluate the reliability, validity, and responsiveness of C-LKS respectively.

Results

Overall, 126 patients with ACL injuries successfully completed the questionnaires. Acceptable internal consistency (Cronbach’s alpha = 0.726) as well as excellent test-retest reliability (ICC = 0.935) was found for C-LKS. Good or moderate correlation (r = 0.514–0.837) was determined among C-LKS and International Knee Documentation Committee Subjective Knee Form (IKDC), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), physical subscales of SF-36; C-LKS also had fair or moderate correlation (r = 0.207–0.462) with the other subscales of SF-36, which adequately illustrated that good validity was included in C-LKS. In addition, good responsiveness was also observed in C-LKS (ES = 1.36,SRM = 1.26).

Conclusions

We have shown that our developed C-LKS questionnaire is reliable, valid and responsible for the evaluation of Chinese-speaking patients with ACL injuries and it would be an effective instrument.

CpG island evolution in the mammalian DHRS4 gene cluster and its role in the regulation of gene transcription

The dehydrogenase/reductase (SDR family) member 4 (DHRS4) gene is copied during mammalian evolution; therefore, while only one DHRS4 gene is expressed in the mouse genome, the gene cluster consists of two (DHRS4 and DHRS4L1) and three (DHRS4, DHRS4L2, and DHRS4L1) copies in chimpanzees and humans, respectively. In this study, we explored the possible regulatory mechanism of the DHRS4 gene cluster in mammalian evolution by analyzing the promoter sequence, methylation of CpG islands, and RNA expression of the DHRS4 gene cluster in mice, chimpanzees, and humans by bioinformatics prediction, bisulfite sequencing PCR, and real-time reverse transcriptase-PCR. The results indicated that the DHRS4 gene was actively expressed in the three model species. The RNA level of DHRS4L1 was much lower than those of DHRS4 and DHRS4L2, and expressed lower homologous sequence identity to DHRS4 and DHRS4L2. DHRS4L2, the latest evolutionary copy of the DHRS4 gene in mammals, received a high promoter prediction score, and was the only copy of the DHRS4 gene cluster presenting hypermethylated CpG islands in the promoter region. An analysis of the relationship between the promoter characteristics and RNA expression of the DHRS4 gene cluster indicated that the development of CpG islands, in addition to the promoter sequence, during mammalian evolution could modulate the dose compensatory regulation of the copy number-varied DHRS4 gene cluster.

Potential involvement of placental AhR in unexplained recurrent spontaneous abortion

Recurrent spontaneous abortion (RSA) is a common complication of pregnancy. Recent studies have demonstrated that the aryl hydrocarbon receptor (AhR) might play important roles in establishing and maintaining early pregnancy. In this study, we found that placental AhR protein levels were significantly lower and placental CYP1A1 mRNA levels were higher in unexplained RSA (URSA) patients than in control subjects. The results of immunohistochemical analyzes showed that placental AhR was expressed in syncytiotrophoblast cells and that the level of AhR was markedly lower in these cells in URSA subjects than in control subjects. β-Naphthoflavone (β-NF, an AhR ligand) at 5μM significantly inhibited proliferation and migration in HTR-8/SVneo cells and was associated with the activation of AhR. Moreover, overexpressing AhR in JAR cells significantly increased CYP1A1 mRNA levels and inhibited cell migration. These results indicate that AhR is highly activated in URSA placentas and that the activation of AhR in the placenta might impair trophoblast cell proliferation and migration, possibly leading to the occurrence of URSA.

Nano-level position resolution for particle tracking in digital in-line holographic microscopy

Three-dimensional particle tracking in biological systems is a quickly growing field, many techniques have been developed providing tracking characters. Digital in-line holographic microscopy is a valuable technique for particle tracking. However, the speckle noise, out-of-focus signals and twin image influenced the particle tracking. Here an adaptive noise reduction method based on bidimensional ensemble empirical mode decomposition is introduced into digital in-line holographic microscopy. It can eliminate the speckle noise and background of the hologram adaptively. Combined with the three-dimensional deconvolution approach in the reconstruction, the particle feature would be identified effectively. Tracking the fixed beads on the cover-glass with piezoelectric stage through multiple holographic images demonstrate the tracking resolution, which approaches 2 nm in axial direction and 1 nm in transverse direction. This would facilitate the development and use in the biological area such as living cells and single-molecule approaches.

Testing the mutant selection window hypothesis in vitro and in vivo with Staphylococcus aureus exposed to fosfomycin

The purpose of this study was to test the mutant selection window (MSW) hypothesis in vitro and in vivo with Staphylococcus aureus exposed to fosfomycin. With the in vitro time-kill studies, S. aureus ATCC 29213 [with a minimal concentration that inhibits colony formation by 99% (MIC99) of 2.2 μg/mL and a mutant prevention concentration (MPC) of 57.6 μg/mL] lost fosfomycin susceptibility at antibiotic concentrations (2×, 4×, and 8× MIC) that are between the lower and upper boundaries of the MSW. In the tissue-cage model, S. aureus was exposed to fosfomycin pharmacokinetics at concentrations below the MIC99, between the MIC99 and the MPC, and above the MPC, respectively. Changes in susceptibility and counts of total and resistant viable bacteria were monitored in tissue-cage fluid obtained daily. However, the selection of resistant mutants was not observed during antibacterial treatment and 48 h after the termination of fosfomycin treatment, regardless of the fosfomycin dosage. Besides, we found no differences between the in vitro-isolated mutant and its sensitive parental strain, which indicates the absence of fitness cost of fosfomycin resistance in S. aureus ATCC 29213. These findings demonstrate that agar plate determinations do not fit the MSW for fosfomycin treatment of rabbits infected with S. aureus ATCC 29213; therefore, the existence of the window must be demonstrated not only in vitro but also in vivo. Further research is needed on the exact mechanism of resistance.

CD38 and E2F transcription factor 2 have uniquely increased expression in rheumatoid arthritis synovial tissues

The purpose of the current study was to find novel rheumatoid arthritis (RA)-specific gene expression by simultaneously comparing the expression profiles of the synovial tissues from patients with RA, osteoarthritis (OA) and ankylosing spondylitis (AS). The Illumina Human HT-12 v4 Expression BeadChip was used to investigate the global gene expression profiles in synovial tissues from RA (n = 12), OA (n = 14) and AS (n = 7) patients. By comparing the profiles in synovial tissues from RA, OA and AS, we identified the CD38, ankyrin repeat domain 38 (ANKRD38), E2F transcription factor 2 (E2F2), craniofacial development protein 1 (CFDP1), cluster of differentiation (CD)7, interferon-stimulated exonuclease gene 20 kDa (ISG20) and interleukin-2 receptor gamma (IL)-2RG genes as differentially expressed gene expression in RA synovial tissues. The increased expression of CD38, E2F2 and IL-2RG, as revealed using real-time polymerase chain reaction (PCR) with synovial tissues from RA (n = 30), OA (n = 26) and AS patients (n = 20), was in agreement with the microarray data. Immunohistochemistry revealed significant CD38 expression and E2F2 in synovial membranes from RA patients (n = 5). The CD38(+) cells had high a percentage in the RA patients' blood (n = 103) and in the CD3(+) and CD56(+) subsets. The CD38(+) cell percentage was correlated significantly with RF level (P = 0·026) in RA patients. The IL-1α and IL-β levels were depressed significantly in the culture medium of RA synovial fibroblast cells (n = 5) following treatment with siRNAs targeting the E2F2 or CD38 genes. This study suggests that the uniquely increased expression of CD38 and E2F2 in RA synovial tissues contribute to the immunoactivation of the disease.

Orexin A-mediated stimulation of 3β-HSD expression and testosterone production through MAPK signaling pathways in primary rat Leydig cells

BACKGROUND

Orexin A (ORA) regulates food intake, energy metabolism, gastrointestinal and reproductive functions.

AIM

The purpose of this study was to demonstrate whether the expression of 3β-hydroxysteroid dehydrogenase (3β-HSD) and testosterone was stimulated by ORA and mediated through mitogen-activated protein kinases (MAPK) in rat Leydig cells.

METHODS

Primary Leydig cells were isolated from male rat testes, cultured, and treated with ORA under various conditions.

RESULTS

Orexin receptor 1 (OX (1) R) mRNA, but not orexin receptor 2 mRNA, was detected in primary Leydig cells. ORA up-regulated the expression of OX( 1) R mRNA and protein in a dose-responsive manner and increased the phosphorylation of extracellular receptor kinase 1/2 (ERK1/2) and p38 MAPK levels, but did not affect the phosphorylation of the JNK MAPK. Phosphorylation of ERK1/2 and p38 MAPKs by ORA was blocked with U0126 and SB203580 inhibitors, respectively. An OX(1)R-specific inhibitor, SB334867, also blocked the phosphorylation of ERK1/2 and p38 by ORA. Inhibitor treatment also blocked 3β-HSD expression and testosterone production.

CONCLUSIONS

These results demonstrate that ORA activation of OX(1)R up-regulates 3β-HSD expression and testosterone production via the ERK1/2 and p38 MAPKs signaling pathways in primary rat Leydig cells.

Efficacy evaluation of two transgenic maize events expressing fused proteins to CrylAb-susceptible and -resistant Ostrinia furnacalis (Lepidoptera: Crambidae)

The Asian corn borer, Ostrinia furnacalis (GuenCe), is a major pest of maize in China. Transgenic Bt maize could provide an effective way to control this pest. However, the potential of resistance evolution has been documented in the laboratory-a CrylAb-resistant strain of Asian corn borer (Asian corn borer-AbR) could survive well on two Bt maize events, that is, MON810 and Bt11. Pyramided transgenic crops with multiple dissimilar Bt insecticidal proteins offer a superior route for pests control compared with that with one Bt single gene. In this study, two novel transgenic Bt maize events (N30 and V3), which contained a fused gene Cry1Ab/Cry2Aj and CrylAb /Vip3DA, respectively, were evaluated for their efficacy on protection against CrylAb-susceptible Asian corn borer (Asian corn borer-BtS) as well as their potential for dealing with the Asian corn borer-AbR. In laboratory bioassay, no neonate larvae of Asian corn borer-BtS fed on the whorl leaves, tassels, husks, silks, and kernels of N30 and V3 could survive at 96 h after infestation. In contrast, only 2.0-8.7% larvae died as they fed on non-Bt maize tissues. As Asian corn borer-AbR neonate larvae fed on N30 and V3 silks and kernels, 95.0% even more larvae were killed at 96 h after infestation, and all died at 168 h after infestation, while 10.0-11.67% larvae survived on non-Bt control. In the field test under artificial infestation at middle whorl leaf and silking stages of maize, there were no significant leaf, silk, and stalk damage on Bt maize plants by comparison with severe leaf feeding, stalk born, and ear damage in control, in addition, the expression profiles of a fused protein of CrylAb/Cry2Aj or CrylAb/Vip3DA in different tissues of N30 and V3 were also confirmed. In conclusion, it is clear that both Bt maize events (N30 and V3) show great potential for protecting maize from attack by Asian corn borer that has resistance to Cry1Ab protein.

Use of extracorporeal membrane oxygenation in tracheal surgery: a case series

OBJECTIVES

To review our experience of extracorporeal membrane oxygenation in airway management during tracheal surgery.

METHODS

A retrospective, observational study was conducted to evaluate the effectiveness of extracorporeal membrane oxygenation in tracheal surgery in Shanghai Chest Hospital between 2008 and 2012.

RESULTS

In all 91 tracheal surgeries, 7 high-risk cases used extracorporeal membrane oxygenation. The duration of extracorporeal membrane oxygenation support ranged from 10 min to 31 min. All extracorporeal membrane oxygenation patients underwent surgical procedures safely and there was no hospital mortality.

CONCLUSIONS

Although various advanced anesthesia techniques can ensure a safe airway in tracheal surgery in most cases, extracorporeal circulation plays an important role in high-risk cases.