[Effect of corneal e-value on myopia control in children and adolescents with orthokeratology]

Objective: To investigate the influence of corneal e-value on the effectiveness of orthokeratology in controlling myopia in children and adolescents. Methods: A retrospective cohort study was conducted, involving the data from 1 563 myopic patients (1 563 eyes) who underwent orthokeratology at the Affiliated Eye Hospital of Shandong University of Traditional Chinese Medicine from June 2015 to August 2021 and adhered to lens wear for at least 2 years. The cohort consisted of 737 males and 826 females with an average age of (10.84±2.13) years. Based on corneal e-value parameters obtained from corneal topography, patients were categorized into a low e-value group (n=425) and a high e-value group (n=1 138). Data on gender, age, parental myopia history, and baseline measures such as spherical equivalent (SE), axial length, and corneal e-value were collected. Differences in axial length change and corneal fluorescein staining rates were compared between the two groups at 1 and 2 years after the start of lens wear. A generalized linear mixed model was established with axial length change as the dependent variable to analyze the correlation between axial length change and baseline corneal e-value. Results: The initial age of the 1 563 myopic patients was (10.84±2.13) years, with a baseline SE of (-3.05±1.30) D. After 1 year of lens wear, the axial length change was (0.20±0.19) mm in the low e-value group and (0.24±0.20) mm in the high e-value group. After 2 years, the changes were (0.38±0.25) mm and (0.43±0.27) mm, respectively, with statistically significant differences (all P<0.05). The incidence of corneal staining after 1 year of lens wear was 9.2% (39/425) in the low e-value group and 14.1% (160/1 138) in the high e-value group. After 2 years, the rates were 15.8% (67/425) and 21.8% (248/1 138), respectively, with statistically significant differences (all P<0.05). After adjusting for parental myopia history, age, SE, and baseline axial length, the baseline corneal e-value was positively correlated with axial length change at 1 and 2 years after lens wear (all P<0.05). Conclusions: Corneal e-value is an independent factor influencing the effectiveness of orthokeratology in controlling myopia. A smaller corneal e-value is associated with slower axial length growth after orthokeratology, indicating better control of myopia in treated eyes.

Targeting human mitochondrial NAD(P)+-dependent malic enzyme (ME2) impairs energy metabolism and redox state and exhibits antileukemic activity in acute myeloid leukemia

Acute myeloid leukemia (AML) is a fast-growing and highly fatal blood cancer, and recent research has shown that targeting metabolism may be a promising therapeutic approach for treating AML. One promising target is the human mitochondrial NAD(P)+-dependent malic enzyme (ME2), which is involved in the production of pyruvate and NAD(P)H and the regulation of the NAD+/NADH redox balance. Inhibition of ME2 via silencing ME2 or utilizing its allosteric inhibitor disodium embonate (Na2EA) causes a decrease in pyruvate and NADH, leading to a decrease in producing ATP via cellular respiration and oxidative phosphorylation. ME2 inhibition also decreases NADPH levels, resulting in an increase in reactive oxygen species (ROS) and oxidative stress, which ultimately leads to cellular apoptosis. Additionally, ME2 inhibition reduces pyruvate metabolism and the biosynthetic pathway. ME2 silencing inhibits the growth of xenotransplanted human AML cells, and the allosteric ME2 inhibitor Na2EA demonstrates antileukemic activity against immune-deficient mice with disseminated AML. Both of these effects are a result of impaired energy metabolism in mitochondria. These findings suggest that the targeting ME2 may be an effective strategy for treating AML. Overall, ME2 plays an essential role in energy metabolism of AML cells, and its inhibition may offer a promising approach for AML treatment.

[Comparison between laparoscopic-assisted natural orifice specimen extraction surgery and conventional laparoscopic surgery for left colorectal cancer: 5-year follow-up results of a randomized controlled study]

Objective: To evaluate the long-term efficacy of laparoscopic-assisted natural orifice specimen extraction surgery (NOSES) colectomy using Cai tube for treating left-sided colorectal cancer. Methods: This was a randomized controlled trial. Inclusion criteria were as follows: preoperative pathological diagnosis of left-sided colorectal adenocarcinoma (rectal, sigmoid colon, descending colon, or left transverse colon cancer with the caudad margin ≥8 cm from the anal margin); preoperative abdominal and pelvic computed tomography (or magnetic resonance imaging) showing maximum tumor diameter <4.5 cm; and BMI <30 kg/m2. Patients with synchronous multiple primary cancers or recurrent cancers, a history of neoadjuvant chemoradiotherapy, preoperative evidence of significant local infiltration, distant metastasis, or complications such as intestinal obstruction and intestinal perforation, or who were not otherwise considered suitable for laparoscopic surgery were excluded. A random number table was used to randomize sequential patients to NOSES surgery using Cai tube (non-assisted incision anal sleeve: patent number ZL201410168748.2) (NOSES group) or traditional laparoscopic-assisted surgery (CLS group). Relevant clinical data of the two groups of patients were analyzed, the main outcomes being disease-free survival, overall survival, overall recurrence rate, and local recurrence rate 5 years after surgery. Results: Patients in both study groups completed the surgery successfully with no requirement for additional surgery. After mean 70 (7-83) months postoperative follow-up, the 5-year overall postoperative survival in the NOSES and CLS groups was 90.0% and 83.3%, respectively (P=0.455); disease free survival was 90.0% and 83.3%, respectively (P=0.455); overall recurrence rate 6.6% and 10.0%, respectively (P=0.625); and local recurrence rate both were 3.3% (P=0.990), respectively. None of these differences was statistically significant. Conclusions: NOSES and CLS have similar long-term efficacy, and NOSES deserves to be used in clinical practice.

Suppression of the human malic enzyme 2 modifies energy metabolism and inhibits cellular respiration

Human mitochondrial NAD(P)⁺-dependent malic enzyme (ME2) is well-known for its role in cell metabolism, which may be involved in cancer or epilepsy. We present potent ME2 inhibitors based on cyro-EM structures that target ME2 enzyme activity. Two structures of ME2-inhibitor complexes demonstrate that 5,5'-Methylenedisalicylic acid (MDSA) and embonic acid (EA) bind allosterically to ME2's fumarate-binding site. Mutagenesis studies demonstrate that Asn35 and the Gln64-Tyr562 network are required for both inhibitors' binding. ME2 overexpression increases pyruvate and NADH production while decreasing the cell's NAD⁺/NADH ratio; however, ME2 knockdown has the opposite effect. MDSA and EA inhibit pyruvate synthesis and thus increase the NAD⁺/NADH ratio, implying that these two inhibitors interfere with metabolic changes by inhibiting cellular ME2 activity. ME2 silence or inhibiting ME2 activity with MDSA or EA decreases cellular respiration and ATP synthesis. Our findings suggest that ME2 is crucial for mitochondrial pyruvate and energy metabolism, as well as cellular respiration, and that ME2 inhibitors could be useful in the treatment of cancer or other diseases that involve these processes.

[Analysis of different protein expression levels in peripheral blood circulating tumor cells from patients with diffuse large B-cell lymphoma and their predictive efficiency for recurrence]

Objective: To analyze the expression levels of differentiation cluster 47 (CD47), signal regulatory protein α (SIRP-α), proto-oncogene (MYC) and proliferating cell associated antigen (Ki67) proteins in peripheral blood circulating tumor cells (CTC) from patients with diffuse large B-cell lymphoma and their predictive efficiency for tumor recurrence. Methods: The data of 82 patients with diffuse large B-cell lymphoma who were confirmed by histopathology and were in remission after chemotherapy in the Hematology Department of Linyi People's Hospital from January 2018 to January 2021 were retrospectively analyzed. There were 44 males and 38 females, and aged from 50 to 75 (63.8±4.6) years. The patients were divided into recurrent group (n=36) and non-recurrent group (n=46) according to their recurrence within 1 year after remission. The fasting peripheral venous blood samples (4 ml) from patients in the morning were collected, and the CTC were isolated. The expression levels of CD47, SIRP-α, MYC and Ki67 proteins in CTC were detected by Western blotting. The correlations between CD47 expression level and SIRP-α, MYC and Ki67 expression levels were analyzed by Pearson correlation analysis. The predictive efficiency of CD47, SIRP-α, MYC and Ki67 expression levels on tumor recurrence was evaluated by receiver operating characteristic (ROC) curves, and the areas under the curve (AUC) were calculated. Results: The expression levels of CD47, SIRP-α, MYC and Ki67 in recurrent group were 2.24±0.23, 1.17±0.12, 1.98±0.20 and 2.63±0.27, while those in non-recurrent group were 2.04±0.21, 1.31±0.13, 1.53±0.16 and 2.24±0.25. The expression levels of CD47, MYC and Ki67 in the recurrent group were higher than those in the non-recurrent group, while the expression levels of SIRP-α were lower than those in the non-recurrent group (all P<0.001). In 82 patients, the expression levels of CD47, SIRP-α, MYC and Ki67 were 2.13±0.22, 1.25±0.13, 1.73±0.18 and 2.41±0.26, respectively. The expression level of CD47 was negatively correlated with the expression level of SIRP-α (r=-0.308, P=0.005), but positively correlated with the expression level of MYC and Ki67 (r=0.484 and 0.332, P=0.012 and 0.003). The sensitivity of CD47, SIRP-α, MYC and Ki67 expression levels in predicting recurrence of diffuse large B-cell lymphoma was 66.7%, 72.2%, 72.2% and 66.7%, with the specificity of 67.4%, 71.7%, 67.4% and 71.7%, and AUC (95%CI) of 0.694 (0.582-0.791), 0.693 (0582-0.790), 0.714 (0.603-0.808) and 0.709 (0.598-0.804), respectively. The sensitivity of the combined detection of the above four indicators was 83.3%, with the specificity of 78.3% and the AUC (95%CI) of 0.864 (0.771-0.930), which was higher than those of the individual detection of each indicator (all P<0.05). Conclusions: The expression level of CD47 was negatively correlated with the expression level of SIRP-α, but positively correlated with the expression level of MYC and Ki67. The expression levels of CD47, SIRP-α, MYC and Ki67 have certain predictive value for tumor recurrence in patients with diffuse large B-cell lymphoma, and the predictive efficiency of combined detection is higher than single indicator detection.

[Evaluation of two biomechanical stiffness indexes in the diagnosis of eratoconus and their changes after corneal collagen cross-linking surgery]

Objective: To evaluate the diagnostic efficacy of stress-strain index (SSI) for different stages or degrees of keratoconus and changes of SSI and stiffness parameter A1 (SPA1) after corneal collagen cross-linking (CXL) surgery. Methods: Cross-sectional study and retrospective case series study. Ninety-four patients (113 eyes) diagnosed as clinical keratoconus (CKC) in Qingdao Eye Hospital from July 2019 to August 2021 were enrolled in the CKC group, including 69 males and 25 females, aged (20.82±4.53) years, and further divided into subgroups of mild (35 patients, 36 eyes), moderate (36 patients, 40 eyes) and severe (33 patients, 37 eyes) CKC. Fifty-six unaffected eyes of monocular keratoconus patients were enrolled in the subclinical keratoconus (SKC) group. Ninety-one healthy subjects (91 eyes) were recruited as the control group. All subjects were examined by Pentacam topography and Corvis ST measurements to obtain mean keratometry, maximal keratometry, deformation amplitude (DA) ratio at 2 mm, integrated radius (IR), Ambrósio's relational thickness to the horizontal profile, corneal central thickness, SPA1 and SSI for comparison. Forty-eight CKC patients (65 eyes) underwent CXL surgery, and the above parameters were recorded before and 3, 6 and 12 months after operation. Data were analyzed by the ANOVA test, Kruskal-Wallis H test, paired sample test, receiver operating characteristic curves and Pearson correlation. Results: The value of SPA1 in the SKC group accounted for 85.53% (87.92±12.38 vs. 102.79±11.74; t=-6.614, P<0.001) compared with the control group, but the value of SSI had no difference in the two groups (t=0.105, P=0.916). The value of SPA1 in the CKC group accounted for 52.87% (54.35±14.70 vs. 102.79±11.74; t=25.985, P<0.001) compared with the control group. The value of SSI in the CKC group accounted for 67.96% (0.70±0.14 vs. 1.03±0.14; t=-15.305, P<0.001) compared with the control group. The more severe the disease was, the smaller the SPA1 and SSI values were 64.27±12.12, 55.22±12.23, 43.75±12.33; 0.78±0.14, 0.71±0.11, 0.61±0.09, and there were significant statistical differences among groups (mild vs. moderate, mild vs. severe, moderate vs. severe; SPA1: t=3.257, -7.249, -4.159; all P<0.001. SSI: t=2.383, 5.065, 2.798; P=0.018,<0.001,=0.006). Receiver operating characteristic analysis showed that SPA1 had good diagnostic efficiency for subclinical patients [area under curve (AUC)=0.802], while the SSI had no diagnostic value (P=0.802). SPA1 had better diagnostic efficiency than the SSI for keratoconus in different stages, especially in the mild CKC and SKC groups (AUC: 0.914 vs. 0.847). The SSI had a significant positive correlation with SPA1 and a significant negative correlation with DA ratio and IR in the control, SKC and CKC groups (r=0.278, 0.368, 0.550; r=-0.346, -0.462, -0.547; r=-0.612, -0.591, -0.718; P<0.01). For patients who received CXL, maximal keratometry decreased significantly at 6 and 12 months postoperatively (t=4.029, 3.633; all P<0.001), whereas SPA1 increased significantly (t=-3.960, -4.500; all P<0.001). However, the SSI only increased significantly at 3 months (t=-2.577, P=0.012) and returned to the preoperative level at 6 and 12 months postoperatively, with no statistical difference compared with the preoperative level (t=-0.544, -0.257; P=0.589, 0.798). Conclusions: While there was no significant change in the SSI of SKC, the SSI of CKC decreased, and the more severe the disease was, the smaller the value was. The SSI was significantly and consistently correlated with DA ratio, IR and SPA1. The SSI compared with SPA1 had a lower degree of identification in different stages and degrees of keratoconus. The consistency of SPA1 with clinical effects after CXL surgery was higher than that of the SSI parameter.

[Comparison between laparoscopic-assisted natural orifice specimen extraction surgery and conventional laparoscopic surgery for left colorectal cancer: a randomized controlled study with 3-year follow-up results]

Objective: To evaluate the mid-term efficacy of laparoscopic-assisted natural orifice specimen extraction surgery (NOSES) colectomy using the Cai tube in the treatment of left colorectal cancer. Methods: A prospective randomized control trial (China Clinical Trials Registration Number: ChiCTR-OOR-15007060) was performed. Sixty patients with left colorectal cancer at Department of Gastrointestinal Surgery of Zhongshan Hospital from September 2015 to August 2017 were prospectively enrolled. Case inclusion criteria: (1) left colorectal adenocarcinoma (rectal cancer with distance ≥ 8 cm from tumor low margin to anal edge, sigmoid colon cancer, descending colon cancer and left transverse colon cancer) confirmed by preoperative pathology; (2) satisfactory conditions of conventional laparoscopic surgery; (3) maximum diameter of the tumor < 4.5 cm confirmed by preoperative abdominal and pelvic CT or MRI; (4) BMI < 30 kg/m². Case exclusion criteria: (1) benign lesions, mucinous adenocarcinoma, signet-ring cell carcinoma and other special pathological types of tumors confirmed by preoperative pathological examination; (2) multiple or recurrent cancers; (3) with a history of neoadjuvant chemoradiotherapy; (4) obvious regional infiltration or distant metastasis indicated by preoperative imaging examination; (5) intestinal obstruction, intestinal perforation, etc. Participants were randomly assigned to NOSES group (using the Cai tube) and conventional laparoscopy (CL) group by random number table method. Clinical data between two groups were compared and analyzed, including perioperative conditions, tumor exfoliation cell detection and bacterial culture results of intraperitoneal lavage fluid, postoperative complications (Clavien-Dindo grading), postoperative pain [visual simulation scoring (VAS) assessment], anal function (Kirwan anal function grading assessment), and postoperative 3-year disease-free survival (DFS), overall survival (OS), overall recurrence rate, and local recurrence rate. Results: A total of 60 patients were enrolled, with 30 in the NOSES group and 30 in the CL group. All the patients in the NOSES group successfully completed operation with Cai tube. Baseline data between the two groups were not significantly different (all P>0.05). There were no statistically significant differences between two groups in conversion rate to open surgery, number of lymph node harivested, proximal and distal resection margin of tumor, negative rate of circumferential margin, operation time, blood loss, inflammatory indexes, postoperative anal function, postoperative hospital stay, hospitalization cost, morbidity of postoperative complications (Clavien-Dindo grade II or above) (all P>0.05). Compared to the CL group, the NOSES group had lower maximum postoperative VAS score (2.5±0.3 vs. 5.1±0.4, t=3.187, P<0.01), and fewer use of additional postoperative analgesia [6.7% (2/30) vs. 33.3% (10/30),χ²=6.670, P=0.02]. The postoperative time to gas passage was shorter in the NOSES group [(2.2±1.4) days vs. (3.1±1.2) days,P=0.026]. No tumor cells and bacterial contamination were found in abdominal lavage fluid before and after operation in either group. The anal function at postoperative 3-month of all the patients in the NOSES group was Kirwan grade I to II, while in the CL group, anal function of 2 cases (6.7%) was Kirwan grade III, and of 28 cases was also Kirwan grade I to II, whose difference was not statistically significant (P>0.05). In the NOSES group and the CL group, 3-year DFS was 96.7% and 83.3% (P=0.090), OS was 100% and 90% (P=0.096), overall recurrence rate was 3.3% and 10.0% (P=0.166), and local recurrence rate was 3.3% and 3.3% (P=0.999), respectively, whose differences were not statistically significant (all P>0.05). Conclusions: In the treatment of left colorectal cancer, compared with conventional laparoscopic colectomy, NOSES colectomy using Cai tube exhibits less scar, less postoperative pain, shorter recovery of gastrointestinal function, and similar mid-term outcomes. Given proper surgical indications, the surgical procedure is safe and feasible.

Peptidylarginine deiminase 2 promotes T helper 17-like T cell activation and activated T cell-autonomous death (ACAD) through an endoplasmic reticulum stress and autophagy coupling mechanism

Peptididylarginine deiminase type 2 (PADI2) catalyzes the conversion of arginine residues to citrulline residues on proteins. We demonstrate that PADI2 induces T cell activation and investigate how PADI2 promotes activated T cell autonomous death (ACAD). In activated Jurkat T cells, overexpression of PADI2 significantly increases citrullinated proteins and induces endoplasmic reticulum (ER) stress and unfolded protein response (UPR) signaling, ultimately resulting in the expression of autophagy-related proteins and autophagy. PADI2 promoted autophagy and resulted in the early degradation of p62 and the light chain 3B (LC3B)-II accumulation. In Jurkat T cells, silencing the autophagy-related gene (Atg) 12 protein inhibits PADI2-mediated autophagy and promotes ER stress and apoptosis, whereas overexpression of Atg12 decreased ER stress and prolonged autophagy to promote cell survival. Additionally, PADI2 regulates T cell activation and the production of Th17 cytokines in Jurkat T cells (interleukins 6, IL-17A, IL-17F, IL-21, and IL-22). In Jurkat T cells, silencing IL-6 promotes autophagy mediated by PADI2 and inhibits PADI2-induced apoptosis, whereas silencing Beclin-1 increases the activation and survival of Th17-like T cells while decreasing autophagy and apoptosis. PADI2 silencing alleviates ER stress caused by PADI2 and decreases cytokine expression associated with Th17-like T cell activation and ACAD. We propose that PADI2 was involved in Th17 lymphocyte ACAD via a mechanism involving ER stress and autophagy that was tightly regulated by PADI2-mediated citrullination. These findings suggest that inhibiting Th17 T cell activation and the development of severe autoimmune diseases may be possible through the use of novel antagonists that specifically target PADI2.

Ornithine decarboxylase functions in both autophagy and apoptosis in response to ultraviolet B radiation injury

We present a mechanism for how ornithine decarboxylase (ODC) regulates the crosstalk between autophagy and apoptosis. In cancer cells, low-intensity ultraviolet B (UVB_L ) induces autophagy while high-intensity UVB (UVB_H ) induces apoptosis. Overexpression of ODC decreases UVB_L -induced autophagy by inhibiting Atg5-Atg12 conjugation and suppressing the expression of autophagy markers LC3, Atg7, Atg12, and BECN1 proteins. In contrast, when ODC-overexpressing cells are exposed to UVB_H radiation, the levels of LC3-II, Atg5-Atg12 conjugate, BECN1, Atg7, and Atg12 increase, while the apoptosis marker cleaved-PARP proteins decrease, indicating that ODC overexpression induced UVB_H -induced autophagy but inhibited UVB_H -induced cellular apoptosis. Additionally, when exposed to UVB_H radiation, silencing BECN1, Atg5, and Atg12 genes results in a decrease in the level of LC3-II proteins but an increase in the level of cleaved-PARP proteins, and apoptotic bodies were significantly increased while autophagosomes were significantly decreased. These findings imply that ODC inhibits apoptosis in cells via the autophagy pathway. The role of Atg12 in ODC-overexpressing cells exposed to UVB_H radiation is investigated using site-directed mutagenesis. Our results indicate that the Atg12-D111S mutant has increased cell survival. The Atg12-ΔG186 mutant impairs autophagy and enhances apoptosis. We demonstrate that when ODC-overexpressing cells are silenced for the Atg12 protein, autophagy and apoptosis are strongly affected, and ODC-induced autophagy protects against UVB_H -induced apoptosis via the Atg12 protein.

[The effect of adjuvant radiotherapy on postoperative complications of immediate deep inferior epigastric artery perforator flap breast reconstruction]

Objective: To examine the effect of adjuvant radiotherapy on postoperative complications of immediate deep inferior epigastric artery perforator (DIEP) flap breast reconstruction. Methods: Data was collected from 185 patients underwent immediate DIEP reconstruction during November 2006 to March 2020 Department of Breast surgery, Fudan University shanghai Cancer Center. All the patients were female, aging (43.0±7.8) years (range: 29 to 61 years). The series included with a total of 187 flaps (2 bilateral, 183 unilateral). Included patients were divided into 2 groups: immediate DIEP reconstruction requring or not requring post-mastectomy radiation therapy (71 cases (71 flaps) in PMRT group, 114 cases (116 flaps) in control group). The aesthetic outcome were measured by Kroll score system and compared between the groups by t test. The complications included partial flap loss, minor necrosis were analyzed between the groups by χ2 test, while the influence of the other correlation factors on complication occurrence was analyzed by Logistic analysis. Results: The controll groups showed higher aesthetic results (2.21±0.55 vs. 2.47±0.82, t=-2.593, P=0.010). Complication rate in PMRT group was higher than that in control group (19.7% (15/71) vs. 4.2% (4/116), χ²=15.079,P<0.01). The complication rate was not correlated with age, body mass index, perforator number, neoadjuvant chemotherapy and adjuvant chemotherapy. Conclusions: Correlation was observed between adiuvant radiotherapy and post-operative complication of the DIEP flap. However, the complication occurrence and aesthetic results remain in the acceptable range. The other factors such as age, body mass index, perforator number, neoadjuvant chemotherapy and adjuvant chemotherapy should not be considered as prognosis factor of post-operative complication of the DIEP flap.

[Evaluation of the diagnosis and treatment of cesarean scar pregnancy induced in the second trimester: a national multicenter retrospective study]

Objective: To study the risk factors of adverse pregnancy outcomes for induced abortion of cesarean scar pregnancy in midtrimester. Methods: A national multicenter retrospective study was conducted. A total of 154 singletons pregnant women with cesarean scar pregnancy during the second trimester induced abortion by various reasons in 12 tertiary A hospitals were selected, their pregnant outcomes were observed and the risk factors of serious adverse outcomes were analyzed with univariate and multivariate logstic regression; the role of ultrasound and MRI in predicting placenta accreta and severe adverse outcomes was evaluated, the effectiveness of uterine artery embolization (UAE) in preventing hemorrhage in pregnant women with and without placenta accreta was compared. Results: Among 154 subjects, the rate of placenta accreta was 42.2% (65/154), the rate of postpartum hemorrhage≥1 000 ml was 39.0% (60/154), the rate of hysterectomy was 14.9% (23/154), the rate of uterine rupture was 0.6% (1/154). The risk factor of postpartum hemorrhage≥1 000 ml and hysterectomy was placenta accreta (P<0.01). For each increase in the number of parity, the risk of placenta accreta increased 2.385 times (95%CI: 1.046-5.439; P=0.039); and the risk of placenta accreta decreased with increasing ultrasound measurement of scar myometrium thickness (OR=0.033, 95%CI: 0.001-0.762; P=0.033). The amount of postpartum hemorrhage and hysterectomy rate in the group with placenta accreta diagnosed by ultrasound combined with MRI were not significantly different from those in the group with placenta accreta diagnosed by ultrasound only or MRI only (all P>0.05). For pregnant women with placenta accreta, there were no significant difference in the amount of bleeding and hysterectomy rate between the UAE group [median: 1 300 ml; 34% (16/47)] and the non-embolization group (all P>0.05); in pregnant women without placenta accreta, the amount of bleeding in the UAE group was lower than that in the non-embolization group (median: 100 vs 600 ml; P<0.01), but there was no significant difference in hysterectomy rate [2% (1/56) vs 9% (3/33); P>0.05]. Conclusions: (1) Placenta accreta is the only risk factor of postpartum hemorrhage≥1 000 ml with hysterectomy for induced abortion of cesarean scar pregnancy in midtrimester; multi-parity and ultrasound measurement of scar myometrium thickness are risk factors for placenta accreta. (2) The technique of using ultrasound and MRI in predicting placenta accreta of cesarean scar pregnancy needs to be improved. (3) It is necessary to discuss of UAE in preventing postpartum hemorrhage for induced abortion of cesarean scar pregnancy in midtrimester.

Denoising method for Raman spectra with low signal-to-noise ratio based on feature extraction

Raman spectroscopy is a non-destructive technique utilizing lasers to observe scattered light in order to determine things such as vibrational modes in the molecular system. A major problem inherent to this technique is that due to their short exposure time and the low power of the excitation laser, Raman signals are very weak. They tend to be much weaker than the noise and can even be drowned out. Conventional denoising methods are currently unable to extract Raman peaks with precision so it is necessary to specifically study Raman signal extraction methods that involve a low signal-to-noise ratio (SNR). In this study, a denoising method for Raman spectra with low SNR based on feature extraction was proposed. Based on the Hilbert Vibration Decomposition (HVD) method, the Raman spectra was decomposed into two components. The peaks were located in the first component and compensated by those in the second component. Then based on the position and height of the peaks, their full widths at half maximum (FWHM) are calculated. Finally, based on the position, height and FWHM of the peaks, Gaussian signals are used to reconstruct the Raman peaks from strong noise and baseline. In the data simulation experiment, the denoising method used improved the SNR from 3.5316 to 130.6386 and the mean square error (MSE) was reduced from 213.8635 to 14.0404. In the actual experiment, this method successfully extracted the characteristic peaks of melamine despite the noise from employing a low excitation laser (10 mW). The characteristics such as the amplitude and position of the peaks were identical to those obtained under a high excitation laser (150 mW). The error of the FWHM under different excitation laser powers (10 and 150 mW) was less than the spectral resolution. Using the method proposed in this paper, the Raman signal of biological samples such as rice leaves were extracted from the raw spectrum, and information on the spectral peak position, amplitude and FWHM were obtained with clarity. The characteristic peaks of the carotene molecule, protein amide I, protein phenylalanine, nucleic acid cytosine, cellulose, DNA phosphodiester, RNA phosphodiester, D-glucose, α-D glucose, chlorophyll, lignin and cellulose were all accurate as well. The results from the simulation data and actual experiments show that a method based on feature extraction can effectively extract Raman peaks even when they are submerged in background noise. It should be noted that the practicality of this method lies in the fact that it requires few parameters and is simple to operate and implement.

Regulation of polyamine homeostasis through an antizyme citrullination pathway

This study reveals an uncovered mechanism for the regulation of polyamine homeostasis through protein arginyl citrullination of antizyme (AZ), a natural inhibitor of ornithine decarboxylase (ODC). ODC is critical for the cellular production of polyamines. AZ binds to ODC dimers and promotes the degradation of ODC via the 26S proteasome. This study demonstrates the protein citrullination of AZ catalyzed by peptidylarginine deiminase type 4 (PAD4) both in vitro and in cells. Upon PAD4 activation, the AZ protein was citrullinated and accumulated, leading to higher levels of ODC proteins in the cell. In the PAD4-overexpressing and activating cells, the levels of ODC enzyme activity and the product putrescine increased with the level of citrullinated AZ proteins and PAD4 activity. Suppressing cellular PAD4 activity reduces the cellular levels of ODC and downregulates cellular polyamines. Furthermore, citrullination of AZ in the C-terminus attenuates AZ function in the inhibition, binding, and degradation of ODC. This paper provides evidence to illustrate that PAD4-mediated AZ citrullination upregulates cellular ODC and polyamines by retarding ODC degradation, thus interfering with the homeostasis of cellular polyamines, which may be an important pathway regulating AZ functions that is relevant to cancer biology.

TRIIODOTHYRONINE ACTIVATES GLYCEROL-3-PHOSPHATE ACYLTRANSFERASE 3 VIA AGGTCA-LIKE-DIRECT-REPEAT-4 TYPE THYROID HORMONE RESPONSE ELEMENT

Background

Thyroid hormone participates in lipid metabolism regulation. However, the effects on triacyleride or triacylglycerol metabolism are complex and not fully clarified yet. In this study, we try to identify novel thyroid hormone-targeting lipogenic metabolic genes and analyze their molecular regulative mechanism.

Method

Thirty-five promoters of twenty-nine human lipogenic regulative enzyme genes were constructed into pXP1 luciferase reporter plasmid (PFK2/FBP2-luc) and transfected into HeGP2 cells, respectively. Gene expression induced by triiodothyronine (T3) was detected by luciferase assay. The T3-activated gene promoter was then analyzed by sequence analysis, deletion and mutation, and electrophoretic mobility shift assay (EMSA).

Results

After 10 nM T3 stimulation for 36 h, phosphogluconate dehydrogenase, malic enzyme, Glycerol-3-phosphate acyltransferase (GPAT) 3, and 1-acylglycerol-3-phosphate O-acyltransferase (AGPAT) 2 were significantly activated, respectively. A AGGTCA-like-direct-repeat-4 consensus thyroid hormone response element (DR4-TRE)-like sequence was found in the GPAT3 promoter, which was then verified to be necessary for T3-induced GPAT3 activation by gene deletion and mutation analysis. EMSA further identified that T3-thyroid receptor (TR) α-retinoid-X receptor (RXR) complex directly bound on the GPAT3 promoter.

Conclusion

Triiodothyronine could activate the GPAT3 through DR4-TRE-like sequence binding to participate in lipogenic regulation. AGPAT2 may be another thyroid hormone target enzyme.

Integrating or Des-integrating agribusiness systems: Outcomes of emergy evaluation

The agribusiness contributes significantly to the Brazilian domestic production, and the search for environmentally friendly systems, exploring the maximum possible use of renewable resources and reducing the use of non-renewable ones, affects the agribusiness' productivity and competitivity. An agribusiness producing corn, eggs, pork and milk was evaluated using emergy accounting. The effects of the (des)integration of the production processes on the efficiency and environmental sustainability of the system were assessed using seven scenarios. The first is the existing integrated system and the others are scenarios in which one of the productive subsystems is removed. Efficiency is measured by the global productivity relative to the amount of protein produced. The most environmentally advantageous scenario, in terms of sustainability and productivity, is the one in which pork production is increased and egg production is ceased. This result suggests that increasing integration per se cannot assure gains in environmental sustainability. The integrated management of the residues of the poultry and pig production as organic fertilizer resulted an advantage for the seven scenarios. The scenarios presented should help to evaluate organizational innovations and to identify trade-offs that could influence the environmental performance of agricultural integrated systems.

The Pluripotency Factor Nanog Protects against Neuronal Amyloid β-Induced Toxicity and Oxidative Stress through Insulin Sensitivity Restoration

Amyloid β (Aβ) is a peptide fragment of the amyloid precursor protein that triggers the progression of Alzheimer's Disease (AD). It is believed that Aβ contributes to neurodegeneration in several ways, including mitochondria dysfunction, oxidative stress and brain insulin resistance. Therefore, protecting neurons from Aβ-induced neurotoxicity is an effective strategy for attenuating AD pathogenesis. Recently, applications of stem cell-based therapies have demonstrated the ability to reduce the progression and outcome of neurodegenerative diseases. Particularly, Nanog is recognized as a stem cell-related pluripotency factor that enhances self-renewing capacities and helps reduce the senescent phenotypes of aged neuronal cells. However, whether the upregulation of Nanog can be an effective approach to alleviate Aβ-induced neurotoxicity and senescence is not yet understood. In the present study, we transiently overexpressed Nanog-both in vitro and in vivo-and investigated the protective effects and underlying mechanisms against Aβ. We found that overexpression of Nanog is responsible for attenuating Aβ-triggered neuronal insulin resistance, which restores cell survival through reducing intracellular mitochondrial superoxide accumulation and cellular senescence. In addition, upregulation of Nanog expression appears to increase secretion of neurotrophic factors through activation of the Nrf2 antioxidant defense pathway. Furthermore, improvement of memory and learning were also observed in rat model of Aβ neurotoxicity mediated by upregulation of Nanog in the brain. Taken together, our study suggests a potential role for Nanog in attenuating the neurotoxic effects of Aβ, which in turn, suggests that strategies to enhance Nanog expression may be used as a novel intervention for reducing Aβ neurotoxicity in the AD brain.

[Clinical short-term and long-term efficacy of endoscopic submucosal dissection in the treatment of early low rectal cancer and precancerous lesions]

Objective: To evaluate the short-term and long-term efficacy of endoscopic submucosal dissection (ESD) in the treatment of early low rectal cancer and precancerous lesions. Methods: Inclusion criteria: (1) Distance from the lower margin of tumor to the anal was ≤ 5 cm. (2) Early low rectal cancers were any size rectal epithelial tumors with infiltration depth limited to the mucosa and submucosa, which were diagnosed by postoperative pathology as high-grade intraepithelial neoplasia or adenocarcinoma of the rectum with infiltration depth of intramucosal or submucosal cancer (M or SM stage). (3) Precancerous lesions included adenoma and low-grade intraepithelial neoplasia of the rectum. (4) Patients received ESD treatment. Patients with tumor invasion depth over submucosa by pathology were excluded. From January 2008 to January 2018, 63 patients meeting the above criteria in Peking University First Hospital were enrolled in this descriptive cohort study. The disease characteristics, clinical manifestations, pathological types, treatment time, hospitalization time, en bloc resection rate (resection of the whole lesion), complete resection rate (both the horizontal and vertical incision margins were negative), postoperative complications and follow-up results were analyzed. Cummulative survival rate was calculated by Kaplan-Meier. Results: The diameter of the lesion was (29.0±23.4) mm and the distance from the lesion to the anus was (2.7±1.8) cm. The median operation time was 45.0 (range, 10.0 to 360.0) minutes, the median hospitalization time was 3.0 (range, 2.0 to 12.0) days, en bloc resection rate was 100%, complete resection rate was 96.8% (61/63), and 1 case (1.6%) had postoperative bleeding. The follow-up rate was 87.3% (55/63) and the median follow-up time was 57.9 (range, 15.6 to 121.1) months. No local recurrence was found during the follow-up period and the 5-year survival rate was 100%. Conclusion: Short- and long-term efficacy of ESD are quite good in the treatment of patients with early low rectal cancer and precancerous lesions.

Functional Roles of Metabolic Intermediates in Regulating the Human Mitochondrial NAD(P)+-Dependent Malic Enzyme

Human mitochondrial NAD(P)⁺-dependent malic enzyme (m-NAD(P)-ME) has a dimer of dimers quaternary structure with two independent allosteric sites in each monomer. Here, we reveal the different effects of nucleotide ligands on the quaternary structure regulation and functional role of the human m-NAD(P)-ME exosite. In this study, size distribution analysis was utilized to investigate the monomer-dimer-tetramer equilibrium of m-NAD(P)-ME in the presence of different ligands, and the monomer-dimer (K_d,12) and dimer-tetramer (K_d,24) dissociation constants were determined with these ligands. With NAD⁺, the enzyme formed more tetramers, and its K_d,24 (0.06 µM) was 6-fold lower than the apoenzyme K_d,24 (0.34 µM). When ATP was present, the enzyme displayed more dimers, and its K_d,24 (2.74 µM) was 8-fold higher than the apoenzyme. Similar to the apoenzyme, the ADP-bound enzyme was present as a tetramer with a small amount of dimers and monomers. These results indicate that NAD⁺ promotes association of the dimeric enzyme into tetramers, whereas ATP stimulates dissociation of the tetrameric enzyme into dimers, and ADP has little effect on the tetrameric stability of the enzyme. A series of exosite mutants were created using site-directed mutagenesis. Size distribution analysis and kinetic studies of these mutants with NAD⁺ or ATP indicated that Arg197, Asn482 and Arg556 are essential for the ATP binding and ATP-induced dissociation of human m-NAD(P)-ME. In summary, the present results demonstrate that nucleotides perform discrete functions regulating the quaternary structure and catalysis of m-NAD(P)-ME. Such regulation by the binding of different nucleotides may be critically associated with the physiological concentrations of these ligands.

[Cost-effectiveness of multiple screening modalities on breast cancer in Chinese women from Shanghai]

Objective: To determine the most cost-effective modality for breast cancer screening in women living in Shanghai. Methods: A Markov model for breast cancer was redeveloped based on true effect which was derived from a project for detection of women at high risk of breast cancer and an organized breast cancer screening program conducted simultaneously in Minhang district, Shanghai, during 2008 to 2012. Parameters of the model were derived from literatures. General principles related to cost-effectiveness analysis were used to compare the costs and effects of 12 different screening modalities in a simulated cohort involving 100 000 women aged 45 years. Incremental cost-effectiveness ratio (ICER) was used to determine the most cost-effective modality. Sensitivity analysis was conducted to evaluate how these factors affected the estimated cost-effectiveness. Results: The modality of biennial CBE followed by ultrasonic and mammography among those with positive CBE was observed as the most cost-effective one. The costs appeared as 182 526 Yuan RMB per life year gained and 144 386 Yuan RMB per quality adjusted life-year (QALY) saved, which were within the threshold of 2-3 times of local per capita Gross Domestic Product. Results from sensitivity analysis showed that, due to higher incidence rate of breast cancer in Shanghai, the cost per QALY would be 64 836 Yuan RMB lower in Shanghai than the average level in China. Conclusion: Our research findings showed that the biennial CBE program followed by ultrasonic and mammography for those with positive CBE results might serve as the optimal breast cancer screening modality for Chinese women living in Shanghai, and thus be widely promoted in this population elsewhere.

Parathyroid hormone (1-34) promotes fracture healing in ovariectomized rats with type 2 diabetes mellitus

Ovariectomized (OVX) rats with type 2 diabetes mellitus (T2DM) with femur fracture received vehicle, insulin, or insulin plus parathyroid hormone (PTH) treatment for 2 and 3 weeks. Radiography, histomorphometry, histology, and immunohistochemistry in callus were evaluated.

INTRODUCTION

Reports about effects of PTH plus insulin on callus formation of osteoporotic fracture with T2DM were limited. This study was designed to investigate the effects of the combination of PTH and insulin on fracture healing in OVX rats with T2DM.

METHODS

Two-month-old female rats were randomly divided into five groups: normal fracture (F), OVX fracture (OF), T2DM + OVX fracture (DOF), insulin-treated (2-4 u/daylight, 4-6 u/night, DOFI), and treated with insulin and PTH (50 μg/kg/day, 5 days/week, DOFIP). A closed mid-shaft fracture was established in the right femurs of all rats after 6 weeks of OVX. Rats were euthanized at 2 and 3 weeks post-fracture according to the time schedule, respectively.

RESULTS

The administration of insulin alone or insulin combined with PTH significantly increased mineralized bone volume fraction (BV/TV) and connectivity density (Conn.D) compared with those of the DOF group at 3 weeks post-fracture and also increased cartilaginous callus area ratio in the DOFI and DOFIP groups at 2 weeks and bony callus area ratio in the DOFIP groups at both the 2 and 3 weeks post-fracture.

CONCLUSIONS

OVX rats with T2DM exhibited a marked delay in the fracture healing process; insulin treatment ameliorated these effects, and the healing process was enhanced following treatment with a combination of insulin and PTH.

[Effect of allogenic mesenchymal stem cells transplantation on the expression of interleukin-22 and matrix metalloproteinase-3 in rats with collagen induced arthritis]

Objective: To study the effect of allogeneic bone marrow mesenchymal stem cells transplantation on the expression of interleukin -22 (IL-22), matrix metalloproteinase -3 (MMP-3) in serum and synovial of rats with collagen induced arthritis. Methods: Type Ⅱ collagen were injected twice to establish the collagen induced arthritis (CIA) rat model. Forty-eight rats were randomly divided into 3 groups: control group, CIA control group, CIA experiment group. Rat bone marrow mesenchymal stem cells were cultured by bone marrow method combined with adherent culture method. After identify, the remaining cells were injected in the CIA experimental group. Enzyme linked immunosorbent assay (ELISA) and immunohistochemistry were used to detect the expression of IL-22 and MMP-3 in serum and anklebone joint's synovium of rats, respectively. Synovial cells were isolated and cultured, and were treated with different concentrations of IL-22. MMP-3 protein and mRNA were detected before and after stimulation by Western blot and real-time quantitative polymerase chain reaction (RT-qPCR). Results: After MSC transplantation, arthritis index, X-ray, HE staining of CIA rat showed that joint damage significantly reduced compared with the control group. The ELISA results showed that the expression of MMP-3 and IL-22 in CIA control group was higher than those in the control group (125.79±9.12 vs 102.00±7.63 ng/ml, P<0.05), (292.35±31.23 vs 257.27±13.99 ng/ml, P<0.05) and CIA experiment group (125.79±9.12 vs 97.94±9.50 ng/ml, P<0.05), (292.35±31.23 vs 262.16±22.02 ng/ml, P<0.05) with statistically significant difference (P<0.05). There was no significant difference between the control group and CIA experimental group. Immunohistochemical showed similar results with ELISA. Western blotting and RT-qPCR showed that MMP-3 protein and mRNA expression was increased after IL-22 stimulation in a dose-dependent manner. Conclusion: IL-22 and MMP-3 play an important role in the pathogenesis of rheumatoid arthritis. IL-22 could regulate the expression of MMP-3, and bone marrow mesenchymal stem cells could reduce the expression of MMP-3 in the treatment of rheumatoid arthritis by reducing the expression of IL-22.

Molecular Interplay between the Dimer Interface and the Substrate-Binding Site of Human Peptidylarginine Deiminase 4

Our previous studies suggest that the fully active form of Peptidylarginine deiminase 4 (PAD4) should be a dimer and not a monomer. This paper provides a plausible mechanism for the control of PAD4 catalysis by molecular interplay between its dimer-interface loop (I-loop) and its substrate-binding loop (S-loop). Mutagenesis studies revealed that two hydrophobic residues, W347 and V469, are critical for substrate binding at the active site; mutating these two residues led to a severe reduction in the catalytic activity. We also identified several hydrophobic amino acid residues (L6, L279 and V283) at the dimer interface. Ultracentrifugation analysis revealed that interruption of the hydrophobicity of this region decreases dimer formation and, consequently, enzyme activity. Molecular dynamic simulations and mutagenesis studies suggested that the dimer interface and the substrate-binding site of PAD4, which consist of the I-loop and the S-loop, respectively, are responsible for substrate binding and dimer stabilization. We identified five residues with crucial roles in PAD4 catalysis and dimerization: Y435 and R441 in the I-loop, D465 and V469 in the S-loop, and W548, which stabilizes the I-loop via van der Waals interactions with C434 and Y435. The molecular interplay between the S-loop and the I-loop is crucial for PAD4 catalysis.

[Expression of Jagged1 mRNA in human epithelial ovarian carcinoma tissues and effect of RNA interference of Jagged1 on growth of xenograft in nude mice]

OBJECTIVE

To investigate the expression of Jagged1 in human epithelial ovarian carcinoma tissues and the effect of Jagged1 on growth of xenograft in nude mice.

METHODS

(1) Forty-eight cases of ovarian cancer and 30 cases of patients with benign epithelial ovarian tumor in the Henan Province Xinxiang Central Hospital during Feb. 2011 to Mar. 2014 were enrolled in this study. The mRNA expression of Jagged1, Notch1 and the downstream target genes Hes1, Hey1 were analyzed by using realtime PCR method. (2) The ovarian cancer xenograft models in nude mice were constructed by injecting SKOV3 cells in axillary subcutaneouswere. The nude mice were randomly divided into Jagged1 interference group, blank plasmid group and control group. Each group had 10 mice. They were transfected with pcDNA3.1(+)-siRNA-Jagged1, blank plasmid pDC3.1 and phosphate buffer, respectively. The tumor volumes and tumor masses were measured 14 days after transfection and the inhibition rate was calculated. The relative mRNA expression of Jagged1, Notch1, Hes1 and Hey1 in xenograft tissues after transfection in each group was detected by using realtime PCR technique and the relative protein expression of Jagged1, Notch1, Hes1 and Hey1 in xenograft tissues was detected by utilizing western blot method.

RESULTS

(1) The relative mRNA expression of Jagged1, Notch1, Hes1 and Hey1 in ovarian cancer tissues were higher than benign ovarian tumor tissues, the differences were statistically significant (P<0.01). (2) The tumor volume was (491± 68) mm(3) and tumor mass was (2.6±0.4) g in Jagged1 interference group, which were significantly lower than that in the blank plasmid group [(842±88) mm(3) and (4.4±0.8) g, respectively] and that in the control group [(851±90) mm(3) and (4.5±0.9) g, respectively; P<0.05], the tumor inhibition rate was 42.2% in Jagged1 interference group, which was significantly higher than that in the blank plasmid group and that in the control group (2.2% and 0, respectively), the differences were statistically significant (P<0.05). The relative mRNA and protein expression of Jagged1, Hes1 and Hey1 in xenograft tissues of nude micein Jagged1 interference group were lower than that in the other two groups, the differences were statistically significant (P<0.05). There were no differences of relative mRNA and protein expression of Notch1 in xenograft tissues of nude mice among the three groups (P>0.05).

CONCLUSIONS

Jagged1 is highly expressed in epithelial ovarian carcinoma. Jagged1 gene interference in xenograft tumor can inhibit ovarian cancer cell growth and improve tumor suppressor rate, which probably play roles by inhibiting Notch1 signaling pathway.

A molecular signature of preclinical rheumatoid arthritis triggered by dysregulated PTPN22

A unique feature of rheumatoid arthritis (RA) is the presence of anti-citrullinated protein antibodies (ACPA). Several risk factors for RA are known to increase the expression or activity of peptidyl arginine deiminases (PADs), which catalyze citrullination and, when dysregulated, can result in hypercitrullination. However, the consequence of hypercitrullination is unknown and the function of each PAD has yet to be defined. Th cells of RA patients are hypoglycolytic and hyperproliferative due to impaired expression of PFKFB3 and ATM, respectively. Here, we report that these features are also observed in peripheral blood mononuclear cells (PBMCs) from healthy at-risk individuals (ARIs). PBMCs of ARIs are also hypercitrullinated and produce more IL-2 and Th17 cytokines but fewer Th2 cytokines. These abnormal features are due to impaired induction of PTPN22, a phosphatase that also suppresses citrullination independently of its phosphatase activity. Attenuated phosphatase activity of PTPN22 results in aberrant expression of IL-2, ATM, and PFKFB3, whereas diminished nonphosphatase activity of PTPN22 leads to hypercitrullination mediated by PADs. PAD2- or PAD4-mediated hypercitrullination reduces the expression of Th2 cytokines. By contrast, only PAD2-mediated hypercitrullination can increase the expression of Th17 cytokines. Taken together, our data depict a molecular signature of preclinical RA that is triggered by impaired induction of PTPN22.

Multifaceted interactions and regulation between antizyme and its interacting proteins cyclin D1, ornithine decarboxylase and antizyme inhibitor

Ornithine decarboxylase (ODC), cyclin D1 (CCND1) and antizyme inhibitor (AZI) promote cell growth. ODC and CCND1 can be degraded through antizyme (AZ)-mediated 26S proteasomal degradation. This paper describes a mechanistic study of the molecular interactions between AZ and its interacting proteins. The dissociation constant (K_d) of the binary AZ-CCND1 complex and the respective binding sites of AZ and CCND1 were determined. Our data indicate that CCND1 has a 4-fold lower binding affinity for AZ than does ODC and an approximately 40-fold lower binding affinity for AZ than does AZI. The K_d values of AZ-CCND1, AZ-ODC and AZ-AZI were 0.81, 0.21 and 0.02 μM, respectively. Furthermore, the K_d values for CCND1 binding to the AZ N-terminal peptide (AZ_34–124) and AZ C-terminal peptide (AZ_100–228) were 0.92 and 8.97 μM, respectively, indicating that the binding site of CCND1 may reside at the N-terminus of AZ, rather than the C-terminus. Our data also show that the ODC-AZ-CCND1 ternary complex may exist in equilibrium. The K_d values of the [AZ-CCND1]-ODC and [AZ-ODC]-CCND1 complexes were 1.26 and 4.93 μM, respectively. This is the first paper to report the reciprocal regulation of CCND1 and ODC through AZ-dependent 26S proteasomal degradation.

A small-molecule inhibitor suppresses the tumor-associated mitochondrial NAD(P)+-dependent malic enzyme (ME2) and induces cellular senescence

Here, we found a natural compound, embonic acid (EA), that can specifically inhibit the enzymatic activity of mitochondrial NAD(P)+-dependent malic enzyme (m-NAD(P)-ME, ME2) either in vitro or in vivo. The in vitro IC50 value of EA for m-NAD(P)-ME was 1.4 ± 0.4 μM. Mutagenesis and binding studies revealed that the putative binding site of EA on m-NAD(P)-ME is located at the fumarate binding site or at the dimer interface near the site. Inhibition studies reveal that EA displayed a non-competitive inhibition pattern, which demonstrated that the binding site of EA was distinct from the active site of the enzyme. Therefore, EA is thought to be an allosteric inhibitor of m-NAD(P)-ME. Both EA treatment and knockdown of m-NAD(P)-ME by shRNA inhibited the growth of H1299 cancer cells. The protein expression and mRNA synthesis of m-NAD(P)-ME in H1299 cells were not influenced by EA, suggesting that the EA-inhibited H1299 cell growth occurs through the suppression of in vivo m-NAD(P)-ME activity EA treatment further induced the cellular senescence of H1299 cells. However, down-regulation of the enzyme-induced cellular senescence was not through p53. Therefore, the EA-evoked senescence of H1299 cells may occur directly through the inhibition of ME2 or a p53-independent pathway.

Receptor for advanced glycation end-products (RAGE) is overexpressed in human osteosarcoma and promotes the proliferation of osteosarcoma U-2OS cells in vitro

Osteosarcoma (OS) is an aggressive cancer of the long bones, and usually affects children and young adults. The receptor for advanced glycation end-products (RAGE) has recently been recognized as an oncogenic receptor that binds to different ligands, and promotes the progression of various cancers. However, little is known about the association between RAGE and the pathogenesis of OS. In this study, we first examined the expression of RAGE in OS tissues using immunohistochemical staining, western blotting, and reverse transcription quantitative polymerase chain reaction. We then determined the influence of the overexpressed RAGE on the proliferation of U-2OS cells in vitro. The results showed that RAGE was overexpressed in OS tissues compared with peritumor tissues, at both the mRNA and protein levels, and there was a significant association between overexpressed RAGE and clinicopathological characteristics, such as clinical stage and distant metastasis. Moreover, the overexpression of RAGE in U-2OS cells significantly promoted their proliferation in vitro. In conclusion, this study indicated that RAGE is overexpressed in OS tissue and promotes the proliferation of U-2OS cells. These data imply that RAGE promotes the growth of OS, and is a potential diagnostic biomarker and therapeutic target for the disorder.

Nodal ratio of positive to excised nodes, but not number of positive lymph nodes is better to predict group to avoid chemotherapy among postmenopausal ER-positive, lymph node-positive T1-T2 breast cancer patients

AIM OF STUDY

To identify whether nodal ratio (NR) of positive to excised nodes is superior to number of positive lymph nodes to predict group to avoid chemotherapy among postmenopausal ER-positive, lymph node-positive, T1-T2 breast cancer patients.

MATERIALS AND METHODS

Postmenopausal estrogen receptor (ER)-positive, lymph node-positive patients who received endocrine therapy (n = 173) with complete baseline data in our hospital between 2000 and 2006 were included. The disease-free survival (DFS) was compared. Survival analysis was performed using Kaplan-Meier method. Cox proportional hazard models were used to evaluate the prognostic value of chemotherapy with different NR for DFS. P--values less than 0.05 were regarded as significant.

RESULTS

The median follow-up was 72 months. Three of 13 variables analyzed remained significantly prognostic for survival in the Cox proportional hazards model. These included age (hazard ratio (HR) =1.642, 95% confidence interval (CI) =1.154-2.337, P = 0.006); histological grade (HR = 2.463,95% CI = 1.389-4.367, P = 0.002); and NR (HR = 2.280, 95% CI = 1.113-4.671, P = 0.024). Subgroup analysis by NR status showed that in patients with NR ≥ 0.20, chemotherapy significantly improves DFS (HR = 0.360, 95% CI = 0.195-0.663, P = 0.001); while in patients with NR < 0.20, chemotherapy did not significantly affect DFS (HR = 0.677, 95% CI = 0.227-2.107, P = 0.493). Radiotherapy is an important factor that improves DFS in lymph node-positive patients, so it is considered in all analysis.

CONCLUSION

This retrospective analysis demonstrates that NR of positive to excised nodes, but not number of positive lymph nodes is better to predict group to avoid chemotherapy among postmenopausal ER-positive, lymph node-positive T1-T2 breast cancer patients.

Differential expression of COX-2 in osteoarthritis and rheumatoid arthritis

In this study, we investigated the differential expression profiles of cyclooxygenase-2 (COX-2) mRNA and proteins in osteoarthritis (OA) and rheumatoid arthritis (RA) patients to elucidate the role of COX-2 expression in the pathogenesis and development of these diseases and to provide novel drug targets for treating arthritis. A total of 60 patients who received arthroscopic surgeries for treating OA (N = 30) or RA (N = 30) were examined. Fifteen normal synovial tissue samples were included as the control group. Fibroblastic synovial cells in all samples were cultured in vitro and COX-2 mRNA, protein expression levels, and COX-2 levels were detected in synovial fluids by real-time polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay methods, respectively. The mRNA level of COX-2 was significantly elevated in synovial cells from OA and RA patients compared to that in control samples (P < 0.05). COX-2 mRNA level was significantly higher in synovial cells from OA patients than in those from RA patients (P < 0.05). Consistent results were obtained for COX-2 protein expression levels from patients' synovial samples. In synovial fluids, OA (P < 0.05), but not RA (P > 0.05), patients showed significantly higher COX-2 levels compared to the control group. Elevated synovial COX-2 expression facilitates the pathogenesis of OA and RA, and thus this index reflects the condition of these 2 diseases.

Polymorphisms in the SIRT5 gene and their association with body measurement and ultrasound traits in Qinchuan cattle

Silent information regulator 5 (SIRT5), a member of the Sirtuin family class III nicotinamide adenine dinucleotide-dependent protein deacetylases, plays an important role in metabolic and aging processes in mammals. We identified 4 single-nucleotide polymorphisms (SNPs) (G22010A, G22052A, G22119T, and G22245C) in the 3' untranslated regions of the SIRT5 gene from 572 Qinchuan cattle by sequencing and investigating their association with growth and ultrasound traits. The frequencies of genotype GG and allele G were high at the 4 SNPs. Based on the X(2) test, the genotypic distributions of the 4 SNPs were not in Hardy-Weinberg equilibrium (P < 0.05 or P < 0.01). Association analysis of individual SNPs and haplotype combinations revealed that the 4 loci were significantly associated with some body measurement and ultrasound traits in Qinchuan cattle, and the H1H5 (AG-GA-GG-GG) diplotypes had better performance than other combinations in Qinchuan cattle. Our results demonstrate that SIRT5 may be a candidate for marker-assisted selection in future breeding programs for Qinchuan cattle.

Retinal nerve fiber layer and macular thinning in systemic lupus erythematosus: an optical coherence tomography study comparing SLE and neuropsychiatric SLE

OBJECTIVE

Due to the lack of reliable biomarkers in diagnosing and monitoring neuropsychiatric systemic lupus erythematosus (NPSLE), the aim of this study was to examine the utility of measurements obtained through spectral domain optical coherence tomography (SD-OCT) as a biomarker for NP involvement in SLE.

METHODS

Retinal nerve fiber layer (RNFL) and macula scans were performed using SD-OCT on 15 NPSLE patients, 16 SLE patients without NP symptoms (non-NP SLE), and 16 healthy controls. Macular volume and thickness of the central macula and peripapillary RNFL were compared between the groups and to scores on two validated cognitive tests.

RESULTS

NPSLE patients did not differ significantly from non-NP SLE patients in retinal thickness or macular volume. However, SLE patients as a whole showed significant RNFL and macular thinning compared to controls. Scores on the Trail Making Test B, a test of complex attention, showed significant correlation to temporal superior and temporal inferior RNFL thickness.

CONCLUSION

Our results demonstrate RNFL thinning in SLE, and confirm the previous finding of high incidence of abnormal brain scans in SLE. These findings suggest that OCT measurements may be indicative of neurodegeneration in SLE and may be a useful biomarker for early cognitive impairment in SLE.

4-Phenylbutyric Acid (4-PBA) and Lithium Cooperatively Attenuate Cell Death during Oxygen-Glucose Deprivation (OGD) and Reoxygenation

Hypoxia is an important cause of brain injury in ischemic stroke. It is known that endoplasmic reticulum (ER) stress is an important determinant of cell survival or death during hypoxia. However, the signaling pathways and molecular mechanisms involved remain to be studied in more detail. To investigate whether inhibition of ER stress promotes neuroprotection pathways, we applied an in vitro oxygen-glucose deprivation (OGD) followed by reoxygenation model of human SK-N-MC neuronal cell cultures in this study. Our results showed that neuronal cell death was induced in this model during the OGD reoxygenation by the sustained ER stress, but not during OGD phase. However, treatment of the cultures with lithium with the OGD reoxygenation insult did not result in neuroprotection, whereas concomitant treatment of chemical chaperon 4-phenylbutyric acid (4-PBA) provides protective effects in ER stress-exposed cells. Moreover, 4-PBA rescued ER stress-suppressed Akt protein biosynthesis, which works cooperatively with lithium in the activation of Akt downstream signaling by inhibition of autophagy-induced cell death. Taken together, our finding provides a possible mechanism by which 4-PBA and lithium contribute to mediate neuroprotection cooperatively. This result may potentially be a useful therapeutic strategy for ischemic stroke.

Clinical research of persimmon leaf extract and ginkgo biloba extract in the treatment of vertebrobasilar insufficiency

This paper aims to compare the curative effects of persimmon leaf extract and ginkgo biloba extract in the treatment of headache and dizziness caused by vertebrobasilar insufficiency. Sixty patients were observed, who underwent therapy with persimmon leaf extract and ginkgo biloba extract based on the treatment of nimodipine and aspirin. After 30 days, 30 patients treated with persimmon leaf extract and 30 patients with ginkgo biloba extract were examined for changes in hemodynamic indexes and symptoms, such as headache and dizziness. The results showed statistically significant differences of 88.3% for the persimmon leaf extract and 73.1% for the ginkgo biloba extract, P < 0.05. Compared to the group of ginkgo biloba extract, the group of persimmon leaf extract had more apparent improvement in the whole blood viscosity, plasma viscosity, fibrinogen, hematokrit, and platelet adhesion rate, and the difference was statistically significant (P < 0.05 or P < 0.01). Based on these analyses, it can be concluded that persimmon leaf extract is better than ginkgo biloba extract in many aspects, such as cerebral circulation improvement, cerebral vascular expansion, hypercoagulable state lowering and vertebrobasilar insufficiency-induced headache and dizziness relief.

Pine (Pinus morrisonicola Hayata) needle extracts sensitize GBM8901 human glioblastoma cells to temozolomide by downregulating autophagy and O(6)-methylguanine-DNA methyltransferase expression

Pine needle extracts of Pinus morrisonicola (Hayata) are commonly used as a functional health beverage. However, it remains unclear what the mechanism is underlying the antitumor activity of pine needle extract. The aims of present study were to investigate the anti-glioblastoma effects of pine needle extracts as well as its bioactive compounds. From three different solvent extracts of pine needles, the water extract displayed the strongest cytotoxicity effects on GBM8901 glioblastoma cells. The isolated compounds were identified as pinocembrin, chrysin, and tiliroside. Chrysin was the most active ingredient of pine needle extract for the induction of apoptosis and suppression of migration and invasion. It also markedly inhibited temozolomide (TMZ)-induced autophagy and O(6)-methylguanine-DNA methyltransferase (MGMT) expression. Because both autophagy and MGMT overexpression have been implicated to TMZ-induced drug resistance in glioblastoma, our results showed that pine needle extract and chrysin may serve as a potential anticancer agent against glioblastoma, especially with regard to sensitizing glioblastoma cells resistant to TMZ.

Human mitochondrial NAD(P)(+)-dependent malic enzyme participates in cutaneous melanoma progression and invasion

Cutaneous melanoma is the most life-threatening neoplasm of the skin, accounting for most of the skin cancer deaths. Accumulating evidence suggests that targeting metabolism is an appealing strategy for melanoma therapy. Mitochondrial NAD(P)(+)-dependent malic enzyme (ME2), an oxidative decarboxylase, was evaluated for its biological significance in cutaneous melanoma progression. ME2 mRNA and protein expression significantly increased during melanoma progression, as evidenced by Gene Expression Omnibus analysis and immunohistochemistry on clinically annotated tissue microarrays, respectively. In addition, ME2 knockdown attenuated melanoma cell proliferation in vitro. ME2 ablation resulted in reduced cellular ATP levels and elevated cellular reactive oxygen species production, which activated the AMP-activated protein kinase pathway and inhibited acetyl-CoA carboxylase. Furthermore, ME2 expression was associated with cell migration and invasion. ME2 knockdown decreased anchorage-independent growth in vitro and tumor cell growth in vivo. These results suggested that ME2 might be an important factor in melanoma progression and a novel biomarker of invasion.

Functional roles of the dimer-interface residues in human ornithine decarboxylase

Ornithine decarboxylase (ODC) catalyzes the decarboxylation of ornithine to putrescine and is the rate-limiting enzyme in the polyamine biosynthesis pathway. ODC is a dimeric enzyme, and the active sites of this enzyme reside at the dimer interface. Once the enzyme dissociates, the enzyme activity is lost. In this paper, we investigated the roles of amino acid residues at the dimer interface regarding the dimerization, protein stability and/or enzyme activity of ODC. A multiple sequence alignment of ODC and its homologous protein antizyme inhibitor revealed that 5 of 9 residues (residues 165, 277, 331, 332 and 389) are divergent, whereas 4 (134, 169, 294 and 322) are conserved. Analytical ultracentrifugation analysis suggested that some dimer-interface amino acid residues contribute to formation of the dimer of ODC and that this dimerization results from the cooperativity of these interface residues. The quaternary structure of the sextuple mutant Y331S/Y389D/R277S/D332E/V322D/D134A was changed to a monomer rather than a dimer, and the K_d value of the mutant was 52.8 µM, which is over 500-fold greater than that of the wild-type ODC (ODC_WT). In addition, most interface mutants showed low but detectable or negligible enzyme activity. Therefore, the protein stability of these interface mutants was measured by differential scanning calorimetry. These results indicate that these dimer-interface residues are important for dimer formation and, as a consequence, are critical for enzyme catalysis.

A novel urine peptide biomarker-based algorithm for the prognosis of necrotising enterocolitis in human infants

OBJECTIVE

Necrotising enterocolitis (NEC) is a major source of neonatal morbidity and mortality. The management of infants with NEC is currently complicated by our inability to accurately identify those at risk for progression of disease prior to the development of irreversible intestinal necrosis. We hypothesised that integrated analysis of clinical parameters in combination with urine peptide biomarkers would lead to improved prognostic accuracy in the NEC population.

DESIGN

Infants under suspicion of having NEC (n=550) were prospectively enrolled from a consortium consisting of eight university-based paediatric teaching hospitals. Twenty-seven clinical parameters were used to construct a multivariate predictor of NEC progression. Liquid chromatography/mass spectrometry was used to profile the urine peptidomes from a subset of this population (n=65) to discover novel biomarkers of NEC progression. An ensemble model for the prediction of disease progression was then created using clinical and biomarker data.

RESULTS

The use of clinical parameters alone resulted in a receiver-operator characteristic curve with an area under the curve of 0.817 and left 40.1% of all patients in an 'indeterminate' risk group. Three validated urine peptide biomarkers (fibrinogen peptides: FGA1826, FGA1883 and FGA2659) produced a receiver-operator characteristic area under the curve of 0.856. The integration of clinical parameters with urine biomarkers in an ensemble model resulted in the correct prediction of NEC outcomes in all cases tested.

CONCLUSIONS

Ensemble modelling combining clinical parameters with biomarker analysis dramatically improves our ability to identify the population at risk for developing progressive NEC.

Fumarate analogs act as allosteric inhibitors of the human mitochondrial NAD(P)+-dependent malic enzyme

Human mitochondrial NAD(P)⁺-dependent malic enzyme (m-NAD(P)-ME) is allosterically activated by the four-carbon trans dicarboxylic acid, fumarate. Previous studies have suggested that the dicarboxylic acid in a trans conformation around the carbon-carbon double bond is required for the allosteric activation of the enzyme. In this paper, the allosteric effects of fumarate analogs on m-NAD(P)-ME are investigated. Two fumarate-insensitive mutants, m-NAD(P)-ME_R67A/R91A and m-NAD(P)-ME_K57S/E59N/K73E/D102S, as well as c-NADP-ME, were used as the negative controls. Among these analogs, mesaconate, trans-aconitate, monomethyl fumarate and monoethyl fumarate were allosteric activators of the enzyme, while oxaloacetate, diethyl oxalacetate, and dimethyl fumarate were found to be allosteric inhibitors of human m-NAD(P)-ME. The IC₅₀ value for diethyl oxalacetate was approximately 2.5 mM. This paper suggests that the allosteric inhibitors may impede the conformational change from open form to closed form and therefore inhibit m-NAD(P)-ME enzyme activity.

Vimentin is involved in peptidylarginine deiminase 2-induced apoptosis of activated Jurkat cells

Peptidylarginine deiminase type 2 (PADI2) deiminates (or citrullinates) arginine residues in protein to citrulline residues in a Ca2+-dependent manner, and is found in lymphocytes and macrophages. Vimentin is an intermediate filament protein and a well-known substrate of PADI2. Citrullinated vimentin is found in ionomycin-induced macrophage apoptosis. Citrullinated vimentin is the target of anti-Sa antibodies, which are specific to rheumatoid arthritis, and play a critical role in the pathogenesis of the disease. To investigate the role of PADI2 in apoptosis, we generated a Jurkat cell line that overexpressed the PADI2 transgene from a tetracycline-inducible promoter, and used a combination of 12-O-tetradecanoylphorbol-13-acetate and ionomycin to activate Jurkat cells. We found that PADI2 overexpression reduced the cell viability of activated Jurkat cells in1a dose- and time-dependent manner. The PADI2-overexpressed and -activated Jurkat cells presented typical manifestations of apoptosis, and exhibited greater levels of citrullinated proteins, including citrullinated vimentin. Vimentin overexpression rescued a portion of the cells from apoptosis. In conclusion, PADI2 overexpression induces apoptosis in activated Jurkat cells. Vimentin is involved in PADI2-induced apoptosis. Moreover, PADI2-overexpressed Jurkat cells secreted greater levels of vimentin after activation, and expressed more vimentin on their cell surfaces when undergoing apoptosis. Through artificially highlighting PADI2 and vimentin, we demonstrated that PADI2 and vimentin participate in the apoptotic mechanisms of activated T lymphocytes. The secretion and surface expression of vimentin are possible ways of autoantigen presentation to the immune system.

Comparative study of emergence agitation between isoflurane and propofol anesthesia in adults after closed reduction of distal radius fracture

Distal radius fracture is a common wound. It is reduced by surgery under anesthesia. Emergence agitation can often occur after anesthesia. It is associated with increased morbidity and hospital costs. However, there have been almost no reports in the medical literature on the occurrence of emergence agitation in adults. This study aimed to compare emergence agitation between isoflurane and propofol anesthesia in adults after closed reduction of distal radius fracture. Forty adults (ASA I-II) undergoing closed reduction of distal radius fracture were randomly assigned to either the isoflurane or propofol group and anesthesia was maintained with isoflurane or propofol. The bispectral index was monitored and maintained within 40-60. After reduction of fracture and fixation with plaster, patients were transported to the post-anesthetic care unit (PACU) and agitation state scale was checked by Aono's four-point scale (AFPS). AFPS score of 3 or 4 was considered to be emergence agitation. Pain scores were measured by the numeric rating scale (NRS) on arrival and at peak value at PACU. Eight (40.0%) patients in the isoflurane group and 2 (10.0%) patients in the propofol group developed emergence agitation (P = 0.031). There was no correlation between peak NRS and AFPS. Propofol may decrease the incidence of emergence agitation compared to isoflurane in adults undergoing closed reduction of distal radius fracture.

Transglutaminase 2 contributes to apoptosis induction in Jurkat T cells by modulating Ca2+ homeostasis via cross-linking RAP1GDS1

Background

Transglutaminase 2 (TG2) is a protein cross-linking enzyme known to be associated with the in vivo apoptosis program of T cells. However, its role in the T cell apoptosis program was not investigated yet.

Results

Here we report that timed overexpression of both the wild type (wt) and the cross-linking mutant of TG2 induced apoptosis in Jurkat T cells, the wt being more effective. Part of TG2 colocalised with mitochondria. WtTG2-induced apoptosis was characterized by enhanced mitochondrial Ca²⁺ uptake. Ca²⁺-activated wtTG2 cross-linked RAP1, GTP-GDP dissociation stimulator 1, an unusual guanine exchange factor acting on various small GTPases, to induce a yet uncharacterized signaling pathway that was able to promote the Ca²⁺ release from the endoplasmic reticulum via both Ins₃P and ryanodine sensitive receptors leading to a consequently enhanced mitochondrial Ca²⁺uptake.

Conclusions

Our data indicate that TG2 might act as a Ca²⁺ sensor to amplify endoplasmic reticulum-derived Ca²⁺ signals to enhance mitochondria Ca²⁺ uptake. Since enhanced mitochondrial Ca²⁺ levels were previously shown to sensitize mitochondria for various apoptotic signals, our data demonstrate a novel mechanism through which TG2 can contribute to the induction of apoptosis in certain cell types. Since, as compared to knock out cells, physiological levels of TG2 affected Ca²⁺ signals in mouse embryonic fibroblasts similar to Jurkat cells, our data might indicate a more general role of TG2 in the regulation of mitochondrial Ca²⁺ homeostasis.

Functional roles of the non-catalytic calcium-binding sites in the N-terminal domain of human peptidylarginine deiminase 4

This study investigated the functional roles of the N-terminal Ca²⁺ ion-binding sites, in terms of enzyme catalysis and stability, of peptidylarginine deiminase 4 (PAD4). Amino acid residues located in the N-terminal Ca²⁺-binding site of PAD4 were mutated to disrupt the binding of Ca²⁺ ions. Kinetic data suggest that Asp155, Asp157 and Asp179, which directly coordinate Ca3 and Ca4, are essential for catalysis in PAD4. For D155A, D157A and D179A, the k_cat/K_m,BAEE values were 0.02, 0.63 and 0.01 s⁻¹mM⁻¹ (20.8 s⁻¹mM⁻¹ for WT), respectively. Asn153 and Asp176 are directly coordinated with Ca3 and indirectly coordinated with Ca5 via a water molecule. However, N153A displayed low enzymatic activity with a k_cat value of 0.3 s⁻¹ (13.3 s⁻¹ for wild-type), whereas D176A retained some catalytic power with a k_cat of 9.7 s⁻¹. Asp168 is the direct ligand for Ca5, and Ca5 coordination by Glu252 is mediated by two water molecules. However, mutation of these two residues to Ala did not cause a reduction in the k_cat/K_m,BAEE values, which indicates that the binding of Ca5 may not be required for PAD4 enzymatic activity. The possible conformational changes of these PAD4 mutants were examined. Thermal stability analysis of the PAD4 mutants in the absence or presence of Ca²⁺ indicated that the conformational stability of the enzyme is highly dependent on Ca²⁺ ions. In addition, the results of urea-induced denaturation for the N153, D155, D157 and D179 series mutants further suggest that the binding of Ca²⁺ ions in the N-terminal Ca²⁺-binding site stabilizes the overall conformational stability of PAD4. Therefore, our data strongly suggest that the N-terminal Ca²⁺ ions play critical roles in the full activation of the PAD4 enzyme.

Endometrial cancer metastasize to the skin of lower leg and vagina: case report and literature review

Endometrial cancer is the most frequent malignancy of the female reproductive system, while cutaneous metastasis is extremely rare in endometrial cancer. The authors herein report a case ofendometrial adenocarcinoma (FIGO Stage IIIC2, Grade 2) with metastasis to the skin of right lower leg and vaginal orifice. The patient was treated with local excision and combination chemotherapy, but she did not respond to therapy and died within 11 months. The authors reviewed the clinico-pathologic features, treatment, and prognosis of such case with cutaneous metastasis.

Identification of immunogenic proteins of Flavobacterium columnare by two-dimensional electrophoresis immunoblotting with antibacterial sera from grass carp, Ctenopharyngodon idella (Valenciennes)

Flavobacterium columnare is a Gram-negative bacterium causing columnaris disease of freshwater fish worldwide, and development of efficacious vaccines has been a continuous challenge in aquaculture. In this study, 14 proteins were identified from cellular components of F. columnare using an immunoblotting approach in two-dimensional electrophoresis map gels with antibacterial sera from grass carp, Ctenopharyngodon idella (Valenciennes), and then anti-grass carp-recombinant Ig (rIg) polyclonal antibodies. These proteins were characterized conclusively by matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF/TOF MS). The 14 proteins are immunogenic molecules of F. columnare, including chaperonins DnaK, GroEL and trigger factor, and translation elongation factor G, translation elongation factor Tu, 30S ribosomal subunit protein S1, dihydrolipoamide succinyltransferase, succinyl-CoA synthetase, SpoOJ regulator protein, alcohol dehydrogenase, fructose-bisphosphate aldolase, 3-hydroxybutyryl-CoA dehydrogenase and two conserved hypothetical proteins. These identified immunogenic proteins may provide candidate molecules for the development of vaccines against columnaris disease.

Determinants of the differential antizyme-binding affinity of ornithine decarboxylase

Ornithine decarboxylase (ODC) is a ubiquitous enzyme that is conserved in all species from bacteria to humans. Mammalian ODC is degraded by the proteasome in a ubiquitin-independent manner by direct binding to the antizyme (AZ). In contrast, Trypanosoma brucei ODC has a low binding affinity toward AZ. In this study, we identified key amino acid residues that govern the differential AZ binding affinity of human and Trypanosoma brucei ODC. Multiple sequence alignments of the ODC putative AZ-binding site highlights several key amino acid residues that are different between the human and Trypanosoma brucei ODC protein sequences, including residue 119, 124,125, 129, 136, 137 and 140 (the numbers is for human ODC). We generated a septuple human ODC mutant protein where these seven bases were mutated to match the Trypanosoma brucei ODC protein sequence. The septuple mutant protein was much less sensitive to AZ inhibition compared to the WT protein, suggesting that these amino acid residues play a role in human ODC-AZ binding. Additional experiments with sextuple mutants suggest that residue 137 plays a direct role in AZ binding, and residues 119 and 140 play secondary roles in AZ binding. The dissociation constants were also calculated to quantify the affinity of the ODC-AZ binding interaction. The K_d value for the wild type ODC protein-AZ heterodimer ([ODC_WT]-AZ) is approximately 0.22 μM, while the K_d value for the septuple mutant-AZ heterodimer ([ODC_7M]-AZ) is approximately 12.4 μM. The greater than 50-fold increase in [ODC_7M]-AZ binding affinity shows that the ODC-7M enzyme has a much lower binding affinity toward AZ. For the mutant proteins ODC_7M(-Q119H) and ODC_7M(-V137D), the K_d was 1.4 and 1.2 μM, respectively. These affinities are 6-fold higher than the WT_ODC K_d, which suggests that residues 119 and 137 play a role in AZ binding.

Hydroxydibenzoylmethane induces apoptosis through repressing ornithine decarboxylase in human promyelocytic leukemia HL-60 cells

Ornithine decarboxylase (ODC) is the rate-limiting enzyme in polyamine biosynthesis and a target for chemoprevention. Hydroxydibenzoylmethane (HDB), a derivative of dibenzoylmethane of licorice, is a promising chemopreventive agent. In this paper, we investigated whether HDB would inhibit the ODC pathway to enhance apoptosis in human promyelocytic leukemia HL-60 cells. We found ODC enzyme activity was reduced during HDB treatment. Overexpression of ODC in HL-60 parental cells could reduce HDB-induced apoptosis, which leads to loss of mitochondrial membrane potential (Δψ(m)), through lessening intracellular ROS. Furthermore, ODC overexpression protected cytochrome c release and the activation of caspase-3 following HDB treatment. The results demonstrated HDB-induced apoptosis was through a mechanism of down-regulation of ODC and occurred along a ROS-dependent mitochondria-mediated pathway.