USP4 inhibits p53 and NF-κB through deubiquitinating and stabilizing HDAC2

Histone deacetylases (HDACs) are major epigenetic modulators involved in a broad spectrum of human diseases including cancers. As HDACs are promising targets of cancer therapy, it is important to understand the mechanisms of HDAC regulation. In this study, we show that ubiquitin-specific peptidase 4 (USP4) interacts directly with and deubiquitinates HDAC2, leading to the stabilization of HDAC2. Accumulation of HDAC2 in USP4-overexpression cells leads to compromised p53 acetylation as well as crippled p53 transcriptional activation, accumulation and apoptotic response upon DNA damage. Moreover, USP4 targets HDAC2 to downregulate tumor necrosis factor TNFα-induced nuclear factor (NF)-κB activation. Taken together, our study provides a novel insight into the ubiquitination and stability of HDAC2 and uncovers a previously unknown function of USP4 in cancers.

Treatment of patients with diabetic peripheral neuropathic pain in China: a double-blind randomised trial of duloxetine vs. placebo

BACKGROUND

Duloxetine has been approved in the United States, European Union and some Asian countries for the treatment of diabetic peripheral neuropathic pain (DPNP). We assessed the efficacy and safety of duloxetine (60 mg once daily) compared with placebo in Chinese patients suffering from DPNP.

METHODS

This was a phase 3, multicenter, randomised, double-blind, parallel, placebo-controlled, 12-week trial of the treatment of DPNP with duloxetine. Subjects were male and female outpatients ≥ 18 years of age with DPNP, as assessed by the Michigan Neuropathy Screening Instrument, and had a rating of ≥ 4 on the Brief Pain Inventory-Modified Short Form-Severity weekly average pain item. The primary efficacy measure was the reduction in pain severity from baseline to 12 weeks, as measured by the weekly mean of 24-h average pain ratings recorded in the patient's diary. Mean changes from baseline in efficacy measures were analysed by a restricted maximum likelihood-based, mixed-effects model repeated measures approach and by analysis of covariance.

RESULTS

Of the 405 patients randomised, 203 patients were assigned to duloxetine 60 mg once daily and 202 patients were assigned to placebo. Duloxetine-treated patients showed significantly greater pain relief on 24-h average pain ratings compared with placebo-treated patients each week of the 12-week study period [week 12: least squares (LS) mean change duloxetine: -2.40, placebo: -1.97; LS mean change difference (95% confidence interval) = -0.43 (-0.82, -0.04), p = 0.030]. Compared with placebo, patients treated with duloxetine experienced higher rates of nausea (p = 0.010), somnolence (p < 0.001) and asthenia (p = 0.002).

CONCLUSIONS

Duloxetine-treated patients showed significantly greater pain relief compared with placebo-treated patients over the 12-week study period. Duloxetine was shown in Chinese patients to have a safety profile similar to that found in previous duloxetine trials.

Magnetism-Driven Ferroelectricity in Double Perovskite Y₂NiMnO₆

We report the discovery of multiferroic behavior in double perovskite Y2NiMnO6. X-ray diffraction shows that the material has a centrosymmetric crystal structure of space group P2(1)/n with Ni(2+)/Mn(4+) ordering. This result is further confirmed by aberration-corrected scanning transmission electron microscopy combined with atomic resolution electron energy loss spectroscopy. The appearance of ferroelectric polarization coincides with the magnetic phase transition (∼67 K), which indicates that the ferroelectricity is driven by magnetism, and this is further confirmed by its strong magnetoelectric (ME) effect. We proposed the origin of the ferroelectricity is associated with the combination of Ni(2+)/Mn(4+) charge ordering and the ↑↑↓↓ spin ordering. When compared with other known magnetic multiferroics, Y2NiMnO6 displays several attractive multiferroic properties, including high polarization (∼145 μC/m(2)), a high multiferroic transition temperature (∼67 K), and strong ME coupling (∼21%).

Negative feedback-defective PRPS1 mutants drive thiopurine resistance in relapsed childhood ALL

Relapse is the leading cause of mortality in children with acute lymphoblastic leukemia (ALL). Among chemotherapeutics, thiopurines are key drugs in ALL combination therapy. Using whole-exome sequencing, we identified relapse-specific mutations in the phosphoribosyl pyrophosphate synthetase 1 gene (PRPS1), which encodes a rate-limiting purine biosynthesis enzyme, in 24/358 (6.7%) relapsed childhood B cell ALL (B-ALL) cases. All individuals who harbored PRPS1 mutations relapsed early during treatment, and mutated ALL clones expanded exponentially before clinical relapse. Our functional analyses of PRPS1 mutants uncovered a new chemotherapy-resistance mechanism involving reduced feedback inhibition of de novo purine biosynthesis and competitive inhibition of thiopurine activation. Notably, the de novo purine synthesis inhibitor lometrexol effectively abrogated PRPS1 mutant-driven drug resistance. These results highlight the importance of constitutive activation of the de novo purine synthesis pathway in thiopurine resistance, and they offer therapeutic strategies for the treatment of relapsed and thiopurine-resistant ALL.

Combined transplantation of autologous hematopoietic stem cells and allogenic mesenchymal stem cells increases T regulatory cells in systemic lupus erythematosus with refractory lupus nephritis and leukopenia

Autologous hematopoietic stem cell (HSC) and mesenchymal stem cell (MSC) transplantation is currently being evaluated as a novel treatment for autoimmune diseases, such as systemic lupus erythematosus (SLE). Here we report a case of autologous HSC transplantation combined with MSCs in a 25-year-old severe SLE patient with multiple life-threatening complications and refractory to conventional cyclophosphamide (CYC) therapy. After being pretreated with CYC, fludarabine and antithymocyte globulin, the patient was transplanted with autologous CD34+HSCs and MSCs by intravenous infusion. Hematopoietic regeneration was observed on day 12 thereafter. After HSC and MSC transplantation, the patient's clinical symptoms caused by SLE were remitted, and the SLEDAI score decreased. Moreover, CD4+CD25+FoxP3+Treg cells increased in peripheral blood mononuclear cells (PBMCs) after transplantation. This result suggests that the combined transplantation of HSCs and MSCs may reset the adaptive immune system to re-establish self-tolerance in SLE. A 36-month follow-up showed that the clinical symptoms remained in remission. Although a longer follow-up is required for assessing the long-term efficacy, our present results suggest that the combined transplantation of HSCs and MSCs may be a novel and effective therapy for refractory SLE.

Visceral fat area is associated with a high risk for early postoperative recurrence in Crohn's disease

AIM

Mesenteric hypertrophy has been recognized as an indicator of the complicated course of Crohn's disease. The aim of this study was to investigate whether the visceral fat area (VFA) is associated with postoperative clinical and endoscopic recurrence.

METHOD

Computed tomography was used to measure the subcutaneous fat area and VFA, and the mesenteric fat index (MFI) was defined as the ratio of the VFA to the subcutaneous fat area. Associations between body mass index, subcutaneous fat area, VFA and MFI and postoperative clinical and endoscopic recurrence were investigated.

RESULTS

The factors associated with postoperative endoscopic recurrence at 6 months after surgery were a high VFA value (P = 0.019) and MFI values above the median (P = 0.008). VFA values were significantly correlated with endoscopic recurrence (r = 0.895, P = 0.040) and endoscopic lesions (r = 0.617, P < 0.0001). Additionally, MFI values correlated well with endoscopic recurrence (r = 0.918, P = 0.02) and endoscopic scores (r = 0.584, P < 0.0001). Multivariate analysis indicated that VFA values above the median (hazard ratio 2.63, 95% CI 1.03-6.74) were predictive of postoperative clinical recurrence in Crohn's disease.

CONCLUSION

A high VFA value is associated with postoperative recurrence of Crohn's disease and has clinical implications with respect to optimizing prophylaxis for each individual. However, further studies are needed to confirm the predictive role of this biomarker in a different data set.

An ecosystem-scale perspective of the net land methanol flux: synthesis of micrometeorological flux measurements

Methanol is the second most abundant volatile organic compound in the troposphere and plays a significant role in atmospheric chemistry. While there is consensus about the dominant role of living plants as the major source and the reaction with OH as the major sink of methanol, global methanol budgets diverge considerably in terms of source/sink estimates reflecting uncertainties in the approaches used to model, and the empirical data used to separately constrain these terms. Here we compiled micrometeorological methanol flux data from eight different study sites and reviewed the corresponding literature in order to provide a first cross-site synthesis of the terrestrial ecosystem-scale methanol exchange and present an independent data-driven view of the land-atmosphere methanol exchange. Our study shows that the controls of plant growth on the production, and thus the methanol emission magnitude, and stomatal conductance on the hourly methanol emission variability, established at the leaf level, hold across sites at the ecosystem-level. Unequivocal evidence for bi-directional methanol exchange at the ecosystem scale is presented. Deposition, which at some sites even exceeds methanol emissions, represents an emerging feature of ecosystem-scale measurements and is likely related to environmental factors favouring the formation of surface wetness. Methanol may adsorb to or dissolve in this surface water and eventually be chemically or biologically removed from it. Management activities in agriculture and forestry are shown to increase local methanol emission by orders of magnitude; they are however neglected at present in global budgets. While contemporary net land methanol budgets are overall consistent with the grand mean of the micrometeorological methanol flux measurements, we caution that the present approach of simulating methanol emission and deposition separately is prone to opposing systematic errors and does not allow taking full advantage of the rich information content of micrometeorological flux measurements.

An ecosystem-scale perspective of the net land methanol flux: synthesis of micrometeorological flux measurements

Methanol is the second most abundant volatile organic compound in the troposphere and plays a significant role in atmospheric chemistry. While there is consensus about the dominant role of living plants as the major source and the reaction with OH as the major sink of methanol, global methanol budgets diverge considerably in terms of source/sink estimates reflecting uncertainties in the approaches used to model, and the empirical data used to separately constrain these terms. Here we compiled micrometeorological methanol flux data from eight different study sites and reviewed the corresponding literature in order to provide a first cross-site synthesis of the terrestrial ecosystem-scale methanol exchange and present an independent data-driven view of the land-atmosphere methanol exchange. Our study shows that the controls of plant growth on the production, and thus the methanol emission magnitude, and stomatal conductance on the hourly methanol emission variability, established at the leaf level, hold across sites at the ecosystem-level. Unequivocal evidence for bi-directional methanol exchange at the ecosystem scale is presented. Deposition, which at some sites even exceeds methanol emissions, represents an emerging feature of ecosystem-scale measurements and is likely related to environmental factors favouring the formation of surface wetness. Methanol may adsorb to or dissolve in this surface water and eventually be chemically or biologically removed from it. Management activities in agriculture and forestry are shown to increase local methanol emission by orders of magnitude; they are however neglected at present in global budgets. While contemporary net land methanol budgets are overall consistent with the grand mean of the micrometeorological methanol flux measurements, we caution that the present approach of simulating methanol emission and deposition separately is prone to opposing systematic errors and does not allow taking full advantage of the rich information content of micrometeorological flux measurements.

AAV-mediated and pharmacological induction of Hsp70 expression stimulates survival of retinal ganglion cells following axonal injury

We evaluated the effect of AAV2- and 17-AAG (17-N -allylamino-17-demethoxygeldanamycin)-mediated upregulation of Hsp70 expression on the survival of retinal ganglion cells (RGCs) injured by optic nerve crush (ONC). AAV2-Hsp70 expression in the retina was primarily observed in the ganglion cell layer. Approximately 75% of all transfected cells were RGCs. RGC survival in AAV2-Hsp70 injected animals was increased by an average of 110% 2 weeks after the axonal injury compared to the control. The increase in cell numbers was not even across the retinas with a maximum effect of approximately 306% observed in the inferior quadrant. 17-AAG-mediated expression of Hsp70 has been associated with cell protection in various models of neurodegenerative diseases. We show here that a single intravitreal injection of 17-AAG (0.2 ug/ul) results in an increased survival of ONC injured RGCs by approximately 49% compared to the vehicle-treated animals. Expression of Hsp70 in retinas of 17-AAG-treated animals was upregulated approximately by 2-fold compared to control animals. Our data support the idea that the upregulation of Hsp70 has a beneficial effect on the survival of injured RGCs, and the induction of this protein could be viewed as a potential neuroprotective strategy for optic neuropathies.

Stapled vs hand suture closure of loop ileostomy: a meta-analysis

AIM

Loop ileostomies are widely used in colorectal surgery to reduce the consequences of distal anastomotic failure. The optimal surgical technique for their closure has yet not been defined. A meta-analysis was performed to compare the outcome after stapled or hand sutured ileostomy closure.

METHOD

An electronic literature search of EMBASE, PubMed and the Cochrane Library was undertaken to identify studies reporting stapled and hand sutured ileostomy closure. End-points included postoperative small bowel obstruction (SBO), anastomotic leakage, wound infection, overall postoperative complications, operation time, hospital stay and surgery-related cost.

RESULTS

Fourteen studies including 5084 patients were identified. Meta-analysis showed that stapled closure was associated with a lower rate of SBO overall (OR = 0.56, P < 0.00001) and early (within 30 days of closure) SBO (OR = 0.51, P < 0.00001). This difference persisted for direct ileostomy closure (OR = 0.62, P = 0.02) or closure with bowel resection and hand sewn anastomosis (OR = 0.44, P < 0.00001). Stapled closure required a shorter inpatient stay (mean difference -1.22, P < 0.0001) and operating time (mean difference -11.21, P = 0.01). No significant difference was noted between the two techniques in terms of anastomotic leakage, wound infection, overall complications or cost.

CONCLUSION

Stapled side-to-side anastomosis is associated with fewer complications, especially SBO, than hand sewn ileostomy closure by direct suture or resection and anastomosis. It is quicker to perform and associated with fewer postoperative bowel obstructions.

Effect of immunization against GnRH on hypothalamic and testicular function in rams

The objective was to determine effects of active immunization against GnRH on reproductive function in Tibetan rams. Peripubertal Tibetan rams (n = 30) were randomly and equally allocated into three groups: control (no treatment); surgically castrated; or immunized against 100-μg d-Lys6-GnRH-tandem-dimer peptide conjugated to ovalbumin in Specol adjuvant at 24 weeks of age (with a booster 8 weeks later). Blood samples (for antibody titers and hormone concentrations) were collected at 4-week intervals until rams were killed (40 weeks). Immunization triggered a good antibody response in all immunized rams (P < 0.01). Compared with intact controls, anti-GnRH immunization reduced (P < 0.01) serum concentrations of testosterone, inhibin A, LH, and FSH, and it induced testicular atrophy (suppression of spermatogenesis). Androstenone concentrations in fat tissues of GnRH-immunized rams were also rendered nondetectable (P < 0.001). Furthermore, mRNA expressions of GnRH receptor, LH-β, and FSH-β in the pituitary and of LH receptor, FSH receptor, and inhibin α and βA subunits in the testes were decreased in immunized rams compared with intact controls (P < 0.05). This was apparently the first report that active immunization against GnRH-tandem-dimer-ovalbumin conjugate in Specol adjuvant was an effective alternative to surgical castration for Tibetan rams under practical Tibetan plateau conditions.

Oral treatment with SEW2871, a sphingosine-1-phosphate type 1 receptor agonist, ameliorates experimental colitis in interleukin-10 gene deficient mice

SEW2871, a selective sphingosine-1-phosphate type 1 receptor (S1P1) agonist, has been shown to be effective in protecting kidneys against ischaemia-reperfusion injury by reducing CD4(+) T cell infiltration in mice. However, the effects of SEW2871 on colitis remain unclear. The aim of this study was to investigate the effects of SEW2871 on established colitis in interleukin (IL)-10 gene-deficient (IL-10(-/-)) mice, a murine model of Crohn's disease (CD). SEW2871 was administered by gavage at a dose of 20 mg/kg/day for 2 weeks to IL-10(-/-) mice. Severity of colitis, serum amyloid A, tissue myeloperoxidase (MPO), T cells in blood and colon lamina propria (LP) and proinflammatory cytokine productions were evaluated. Furthermore, the phospho-signal transducer and activator of transcription (STAT)-3 (p-STAT-3) expression in lymphocytes isolated from colon LP was also assessed. The 2-week administration of SEW2871 ameliorated established colitis in IL-10(-/-) mice, associated with a reduction of serum amyloid A concentration, a decreased colon MPO concentration, a depletion of the peripheral CD4(+) CD45(+) T cells and a reduction of the homing of T cells into colon LP. Moreover, typical cytokines of T helper type 1 (Th1) and Th17 cells and p-STAT-3 expression were also suppressed by SEW2871 treatment. SEW2871 treatment ameliorates established experimental colitis in IL-10(-/-) mice, which may provide a new therapeutic approach for human CD therapy.

L-asparaginase induces in AML U937 cells apoptosis via an AIF-mediated mechanism

Acute Myeloid Leukemia (AML), a cancer of the myeloid line of blood cells, progresses rapidly and is typically fatal within weeks or months if left untreated. Asparaginases are a class of enzymatic anti-leukemia agents that induce apoptosis in leukemia cell lines; however, the role of L-asparaginase in the induction of apoptosis in AML cells has not been investigated. In this study, we investigated the apoptosis-inducing effect of L-asparaginase and its underlying mechanism in AML U937 cells. The results showed that L-asparaginase significantly inhibited the proliferation of U937 cells by inducing apoptosis. Furthermore, the low baseline expression level of asparaginase synthase (ASNS) demonstrated the sensitivity of U937 cells and AML M5, a rare subtype of AML, to L-asparaginase. Apoptosis induced by L-asparaginase is mediated by apoptosis-inducing factor (AIF). Our findings show the potential of L-asparaginase as an effective approach in treating AML via the induction of apoptosis mediated by AIF.

Intestinal dysbacteriosis contributes to decreased intestinal mucosal barrier function and increased bacterial translocation

The purpose of this study was to determine the effect of colistin-induced intestinal dysbacteriosis on intestinal mucosal barrier function and bacterial translocation in a mouse model. Colistin or saline was administered orally for 7 days, and populations of viable organisms from the caecal mucosa and its content, the ileal segments, the mesenteric lymph nodes (MLNs) and the internal organs were prepared for examination. In the intestinal dysbacteriosis model, intestinal barrier dysfunction was observed and associated with increased bacterial translocation to extraintestinal sites. The extent of bacterial translocation to the MLNs and internal organs in the colistin group was significantly higher than in the saline group. Colistin-induced intestinal dysbacteriosis was shown to injure the intestinal mucosa barrier function and increase bacterial dislocation.

SIGNIFICANCE AND IMPACT OF THE STUDY

Colistin has been reported to be effective in selective digestive decontamination (SDD), which is an infection prevention measure used in the treatment of certain patients in intensive care. We are the first to report that colistin-induced intestinal dysbacteriosis can injure intestinal mucosal barrier function and increase bacterial translocation, whereas a high dose of colistin does not damage the intestinal mucosal barrier in germ-free (GF) mice raised in a GF environment. These results may indicate that prolonged use of a high dose of a SDD medication should be carefully considered.

H19 DMR methylation correlates to the progression of esophageal squamous cell carcinoma through IGF2 imprinting pathway

BACKGROUND

H19 gene has been proved to be essential for human tumor growth which contains CpG rich regions. Imprinted gene expression in many cancers is usually associated with the function of methylation. We performed this study to better understand wether H19 DMR methylation correlates to the progression of esophageal squamous cell carcinoma through IGF2 imprinting pathway.

METHODS

LOI of IGF2 was detected in 276 samples, which were determined as heterozygote with ApaI polymorphism in exon 9 of IGF2 by PCR-RFLP and RT-PCR-RFLP. Methylation status of H19 DMR in informative samples was analyzed by bisulfite sequencing PCR. IGF2 expression was examined by real-time PCR and IHC.

RESULTS

208 ESCC patients were informative for ApaI polymorphism. 92 tumor and 30 normal tissues showed IGF2 LOI. Methylation status of H19 CBS6 was higher in patients with IGF2 LOI compared to patients with IGF2 MOI (p < 0.05). IGF2 expression in patients with IGF2 LOI was higher than patients with IGF2 MOI (p < 0.05) which was correlated with lymph node involvement, neoplastic grade and metastasis (p < 0.05).

CONCLUSIONS

Our results suggested that H19 CBS6 hypermethylation is related to the LOI of IGF2 which usually leads to an overexpression of IGF2, playing important roles in the occurrence, development as well as metastasis of ESCC. Therefore, H19 CBS6 methylation potentially represents a novel clinically relevant epigenetic marker to identify individuals at increased risk for the occurrence, progression and prognosis of ESCC.

Anisomycin induces apoptosis of glucocorticoid resistant acute lymphoblastic leukemia CEM-C1 cells via activation of mitogen-activated protein kinases p38 and JNK

Glucocorticoids (GCs) resistance is frequently encountered in children with acute lymphoblastic leukemia (ALL), especially in T-ALL, which usually results in failure of treatment. To find new agent to overcome GC resistance of ALL is an urgent problem. Here we investigated potential effect of anisomycin on GC-resistant T-ALL CEM-C1 cells and explored involved molecular mechanisms. Dramatic growth inhibition and apoptosis in GC resistant CEM-C1 cells and GC-sensitive CEM-C7 cells induced by anisomycin were observed, which presented in a concentration- and time-dependent manner. Correspondingly, anisomycin induced cleaved caspase-3 and up-regulation of pro-apoptotic proteins (BimEL and Bad), meanwhile down-regulation of anti-apoptotic proteins (Mcl-1 and Bcl-2), both in a dose- and time-dependent manner in GC resistant CEM-C1 cells. Anisomycin also induced cell cycle arrest at G0/G1 phase in CEM-C1 cells through increasing expressions of p21 and p27, and attenuating the expression of cyclinA. The rapid up-regulation of phosphorylated mitogen-activated protein kinases (MAPKs) p38 and Jun N-terminal kinase (JNK) were observed after CEM-C1 cells were incubated with anisomycin. The activation of p38 and JNK could be blocked by respective inhibitors (SB203580 for p38 and SP600125 for JNK) accompanied with the inhibition of apoptosis and changes of apoptosis associated proteins in CEM-C1 cells. These results suggested that anisomycin induced apoptosis of CEM-C1 cells via activation of p38 and JNK, and might be an attractive new agent for treatment of GC-resistant ALL.

Fiber-optic two-photon optogenetic stimulation

Optogenetic stimulation of genetically targeted cells is proving to be a powerful tool in the study of cellular systems, both in vitro and in vivo. However, most opsins are activated in the visible spectrum, where significant absorption and scattering of stimulating light occurs, leading to low penetration depth and less precise stimulation. Since we first (to the best of our knowledge) demonstrated two-photon optogenetic stimulation (TPOS), it has gained considerable interest in the probing of cellular circuitry by precise spatial modulation. However, all existing methods use microscope objectives and complex scanning beam geometries. Here, we report a nonscanning method based on multimode fiber to accomplish fiber-optic TPOS of cells.