Mdm2 Promotes Odontoblast-like Differentiation by Ubiquitinating Dlx3 and p53

Dentin is an important structural component of the tooth. Odontoblast differentiation is an essential biological process that guarantees normal dentin formation, which is precisely regulated by various proteins. Murine double minute 2 (Mdm2) is an E3 ubiquitin ligase, and it plays a pivotal role in the differentiation of different cell types, such as osteoblasts and myoblasts. However, whether Mdm2 plays a role in odontoblast differentiation remains unknown. Here, we investigated the spatiotemporal expression of Mdm2 by immunostaining and found that Mdm2 was highly expressed in the odontoblasts and slightly in the dental papilla cells of mouse incisors and molars. Gene knockdown and overexpression experiments verified that Mdm2 promoted the odontoblast-like differentiation of mouse dental papilla cells (mDPCs). Intranuclear colocalization and physical interaction between Mdm2 and distal-less 3 (Dlx3), a transcription factor important for odontoblast differentiation, was found during the odontoblast-like differentiation of mDPCs by double immunofluorescence and immunoprecipitation. Mdm2 was proved to monoubiquitinate Dlx3, which enhanced the expression of Dlx3 target gene Dspp. In addition, p53, the canonical substrate of Mdm2, was validated to be also ubiquitinated but degraded by Mdm2 during the odontoblast-like differentiation of mDPCs. Gene knockdown experiments confirmed that p53 inhibited the odontoblast-like differentiation of mDPCs. p53 and Mdm2 double knockdown partially rescued the reduced odontoblast-like differentiation by knockdown of Mdm2 alone. Taken together, our study revealed that Mdm2 promoted the odontoblast-like differentiation of mDPCs by ubiquitinating both Dlx3 and p53. On one hand, the monoubiquitination of Dlx3 by Mdm2 led to upregulation of Dspp, which is a marker of the odontoblast differentiation. On the other hand, ubiquitination of p53 by Mdm2 resulted in its degradation, which eliminated the inhibitory effect of p53 on the odontoblast-like differentiation of mDPCs.

The association between gestational diabetes mellitus and cancer in women: A systematic review and meta-analysis of observational studies

AIM

Both type 1 and type 2 diabetes are associated with greater risk of a variety of cancers. However, the association between gestational diabetes mellitus (GDM) and risk of cancer has so far not been well addressed. This study aimed to summarize the epidemiological evidence of the association between GDM and subsequent risk of cancer.

METHODS

PubMed and Embase databases were searched for relevant studies, and a random-effects model was used to calculate the summary relative risks (RRs) along with the corresponding 95% confidence intervals (CIs).

RESULTS

A total of 17 observational studies were selected, comprising 7 case-control and 10 cohort studies. Pooled effect estimates retrieved from these 17 studies showed that GDM was associated with an increased risk of breast cancer in Asia (pooled RR: 1.31, 95% CI: 1.01-1.70), but not in other regions, and also with thyroid cancer (RR: 1.28, 95% CI: 1.16-1.42), stomach cancer (RR: 1.43, 95% CI: 1.02-2.00) and liver cancer (RR: 1.27, 95% CI: 1.03-1.55). However, GDM was not associated with any increased risk of colon (RR: 1.41, 95% CI: 0.90-2.21), colorectal (RR: 1.16, 95% CI: 0.95-1.41), ovarian (RR: 1.14, 95% CI: 0.90-1.44), cervical (RR: 1.02, 95% CI: 0.81-1.29), pancreatic (RR: 3.49, 95% CI: 0.80-15.23), brain and nervous system (RR: 1.26, 95% CI: 0.80-1.97), blood (leukaemia, RR: 0.77, 95% CI: 0.45-1.30), endometrial (RR: 0.77, 95% CI: 0.20-2.98), skin (RR: 1.13, 95% CI: 0.81-1.59) or urological (RR: 0.98, 95% CI: 0.73-1.31) cancers.

CONCLUSION

GDM is associated with a greater risk of cancer in women, including breast, thyroid, stomach and liver cancers. However, further investigation is nonetheless warranted.

Novel Reassortant Avian Influenza A(H9N2) Virus Isolate in Migratory Waterfowl in Hubei Province, China

In December 2017, an influenza A(H9N2) virus (B51) was isolated from migratory waterfowl in Hubei Province, China. Phylogenetic analysis demonstrated that B51 is a novel reassortant influenza virus containing segments from human H7N4 virus and North American wild bird influenza viruses. This suggest that B51 has undergone multiple reassortment events.

[Safety evaluation on different ventilation strategies set for neonatal respiratory distress syndrome: a network Meta-analysis]

Objective: To evaluate the relative safety of different ventilation methods regarding mortality and rates of complication, on neonatal respiratory distress syndrome (NRDS). Methods: Network Meta-analysis was used to collect data on randomized controlled trials of pulmonary ventilation strategies in preterm infants with a mean gestational age of less than 32 weeks. Diagnostic criteria on NRDS were published in the PubMed, Cochrane, Web of Science, EBSCO, and Springer Link databases from January 1986 to June 2018. Revman 5.3 software was used to evaluate the quality of studies, based on the Cochrane quality assessment tool. Data were analyzed by Bayesian and frequency methods, using both Win BUGS 1.4.3 and STATA 13.0 software. Safety of different ventilation strategies for NRDS mortality and complications would include intraventricular hemorrhage (IVH), patent ductus arteriosus (PDA) and retinopathy of prematurity (ROP) and were evaluated. Counted data was displayed by OR and 95%CI. Results: A total of 31 RCTs were included in this paper, including 5 827 preterm infants and 11 ventilation strategies. There were no statistically significant differences appearing in 11 ventilation strategies on mortality, PDA or ROP. IVH results were reported in 28 studies. Compared with nasal intermittent positive pressure ventilation (NIPPV), both high- frequency oscillation ventilation (HFOV) (OR=3.33, 95%CI: 1.08-16.67, P<0.05) and synchronized intermittent mechanical ventilation (SIMV) (OR=8.22, 95%CI: 1.25-29.44, P<0.05) schemes seemed to have increased the risk of IVH in preterm infants with NRDS. NIPPV appeared the optimal ventilation strategy in the rankings of cumulative probability. Results on clustering showed that NIPPV was probably the best ventilation strategy for children with NRDS after considering the orders of IVH, PDA and ROP on mortality, respectively. However, HFOV, IMV, and SIMV did not seem to be the ideal ventilated strategies. Conclusions: Most of the clinical decision makers might prefer using NIPPV in the treatment of children with NRDS through mechanical ventilation systems to reduce both the incidence and death caused by IVH, PDA and ROP. It was not recommended to use HFOV, SIMV and IMV in treating NRDS with gestational less than 32 weeks. We suggested that larger numbers of multi-center RCTs ba carried out to make the above conclusions more convincing.

Pyrroloquinoline quinone protected autophagy-dependent apoptosis induced by mono(2-ethylhexyl) phthalate in INS-1 cells

Mono(2-ethylhexyl) phthalate (MEHP) is the main metabolite of di(2-ethylhexyl) phthalate (DEHP) in organisms and is commonly used as a plasticizer. Exposure to DEHP impairs the function of islet beta cells (INS-1 cells), which is related to insulin resistance and type 2 diabetes. At present, some research data have also confirmed that MEHP has a certain damage effect on INS-1 cells. In our experiment, we found that MEHP would lead to the increase of reactive oxygen species (ROS) and the upregulation of autophagy. And downregulated ROS production by N-acetyl-L-cysteine could also reduce autophagy. In addition, MEHP-induced lysosomal membrane permeability (LMP) subsequently released cathepsin D. Additionally, MEHP induced the collapse of mitochondrial transmembrane potential and release of cytochrome c. Addition of autophagy inhibitor 3-methyladenine relieved MEHP-induced apoptosis as assessed by the expression of cleaved caspase 3, cleaved caspase 9, and terminal deoxynucleotidyl transferase dUTP nick end labeling assay, indicating that MEHP-induced apoptosis was autophagy dependent. Cathepsin D inhibitor, pepstatin A, suppressed MEHP-induced mitochondria release of cytochrome c and apoptosis as well. Meanwhile, pyrroloquinoline quinone (PQQ), a new B vitamin, improved the above phenomenon. Taken together, our results indicate that MEHP induces autophagy-dependent apoptosis in INS-1 cells by lysosomal-mitochondrial axis. PQQ improved this process by downregulating ROS and provided a degree of protection. Our study provides a new perspective for MEHP on the cytotoxic mechanism and PQQ protection in INS-1 cells.

[Related factors of frailty in the elderly male patients with chronic kidney disease]

Objective: To investigate the characteristics of frailty in the elderly male patients with chronic kidney disease (CKD) and the effects of renal function on the incidence of frailty. Methods: A total of 105 non-dialysis CKD patients aged ≥65 years who were admitted to the Chinese PLA General Hospital between October 1, 2018 and January 30, 2019 were included in this study. Their clinical data and laboratory indicators were collected. Frailty was defined according to Fried frailty criteria. According to the frailty scores, the participants were categorized as non-frail (n=37), intermediately frail (n=37) and frail (n=31). The association of frailty and the level of estimated glomerular filtration rate (eGFR) in the patients was analyzed using the model of multivariate Logistic regression. Results: Among the 105 patients, the mean age was 74 (68, 77) years old. The incidence of frail and intermediate frail was 35.2% (37/105) and 29.5% (31/105), respectively. Multivariate logistic analysis showed statistically significant associations of frailty with age (OR=1.14, 95%CI:1.08-1.20, P<0.001), body mass index (OR=0.87, 95%CI:0.79-0.95, P=0.001) and the level of eGFR (OR=0.98, 95%CI:0.96-0.99, P=0.003) in those patients. The incidence of frail in patients with eGFR<45 ml·min(-1)·(1.73 m(2))(-1) and 45-59 ml·min(-1)·(1.73 m(2))(-1) was 1.02 (OR=2.02, 95%CI: 1.06~3.87) and 0.84 (OR=1.84, 95%CI: 1.05-3.22) times higher than that of eGFR≥60 ml·min(-1)·(1.73 m(2))(-1), respectively. Conclusion: The incidence of frailty in the elderly patients with CKD is affected by many factors, such as age, body mass index and renal function, and increases with decreased renal function.

P3390Relationship of thrombus healing to underlying plaque characteristics in ST-segment elevation myocardial infarction: an optical coherence tomography study

Background

Acute ST-segment elevation myocardial infarction (STEMI) is typically characterized by an occlusive coronary thrombus propagation on a disrupted or eroded atherosclerotic plaque. A variable period of plaque instability and thrombus formation occur days or weeks old in approximately 50% of patients with STEMI. Presence of late stage (older) thrombi in aspirated coronary material is an independent predictor of 1-year and long-term mortality in STEMI patients. However, the relationship between coronary thrombus healing to underlying plaque morphology and characteristics in vivo still remains largely unknown.

Purpose

Our objective was to assess differences in thrombus healing between ruptured and eroded plaques in vivo and evaluate the impact of underlying plaque characteristics on thrombus healing using optical coherence tomography (OCT).

Methods

Analyzable coronary material was obtained during primary percutaneous coronary intervention (PCI) from 135 patients with STEMI within 12h of symptom onset. Thrombi were morphologically classified as either early or late stage (lytic changes or organization). Of the 135 patients, 110 were eligible for culprit lesion evaluation using OCT. Quantitative and qualitative underlying plaque characteristics were assessed by OCT.

Results

Late-stage thrombi were found in 49 of 110 (44.5%) culprit plaques. Patients with eroded plaques more frequently had late-stage thrombi compared with ruptured plaques (59.0% vs. 36.6%, p<0.001). Subgroup analysis was performed between plaque rupture, identified in 71 patients (64.5%) and plaque erosion in 39 patients (35.5%). In plaque ruptures, patients with late-stage thrombi had larger lipid core length (12.4±3.3 vs. 14.5±3.8, p=0.020), larger rupture cavity length [1.5 (1.0, 2.0) vs. 1.9 (1.5, 2.8), p=0.034] and increased residual thrombus length [7.8 (6.3, 11.2) vs. 10.3 (7.8, 13.8), p=0.021] assessed by OCT compared with early thrombus group. However, in plaque erosions, late stage thrombi were associated with decreased residual thrombus burden compared with patients with early thrombus group [16.8 (12.8, 20.4) vs. 13.4 (10.7, 14.8), p=0.012]. No significant difference was found between thrombus healing with peak creatine kinase concentration or maximum NT-pro BNP in subgroup analysis.

Conclusions

Coronary thrombi in STEMI patients exhibited diverse phases of healing, depending on the etiology of the underlying culprit plaque in vivo. These observations indicate entirely distinct mechanisms of thrombus propagation, maturation and healing between plaque rupture and erosion, illustrating an opportunity for more tailored treatment in patients with different plaque type.

[Comparison the clinical efficacy of 3D versus 2D total laparoscopic thyroidectomy for thyroid cancer by via-breast approach]

Objective:To summarize and analyze the clinical efficacy of 3D and 2D laparoscopic surgery in thyroidectomy for thyroid cancer. Method: Thirty-seven patients with early-differentiated thyroid cancer underwent laparoscopic surgery from August 2016 to November 2018. Their clinical data were retrospectively analyzed. They were divided into 3D laparoscopic group and 2D laparoscopic group based on laparoscopic imaging systems. The perioperative clinical indicators and postoperative complications of the two groups were compared. Result: Compared with the 2D laparoscopic group, the 3D laparoscopic group had shorter operation time and less bleeding, and the incidence of postoperative complications was less, but the differences between the two groups were not statistically significant(P>0.05). Conclusion: Compared with the 2D laparoscopic thyroidectomy, 3D laparoscopic thyroidectomy for thyroid cancer allows higher surgical precision, shorter operation time, lower operation risk and smoother surgical procedure, thus improves surgical efficiency.

[The mediating role of psychological resilience to childhood abuse and binge eating among middle school students]

To explore the mediating role of psychological resilience to childhood abuse and binge eating. This study assessed the childhood abuse, binge eating and psychological resilience of 3 453 middle school students in Harbin city, Heilongjiang Province. SPSS PROCESS macro program, combined with Bootstrap method, was employed to explore the mediating effect of psychological resilience. The incidence of middle school students experiencing at least one type of abuse in their childhood was 81.3% (2 807/3 453). Childhood abuse, psychological resilience and binge eating were all significantly different in terms of gender, household registration and whether they were only child (all P values<0.05). There was a significant positive correlation between childhood abuse and binge eating. Psychological resilience was negatively associated with childhood abuse and binge eating. Childhood abuse could not only directly predict the binge eating behavior of adolescents, but also could indirectly affect it via psychological resilience.

Flightless I exacerbation of inflammatory responses contributes to increased colonic damage in a mouse model of dextran sulphate sodium-induced ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by cytokine driven inflammation that disrupts the mucosa and impedes intestinal structure and functions. Flightless I (Flii) is an immuno-modulatory protein is a member of the gelsolin family of actin-remodelling proteins that regulates cellular and inflammatory processes critical in tissue repair. Here we investigated its involvement in UC and show that Flii is significantly elevated in colonic tissues of patients with inflammatory bowel disease. Using an acute murine model of colitis, we characterised the contribution of Flii to UC using mice with low (Flii+/-), normal (Flii+/+) and high Flii (FliiTg/Tg). High levels of Flii resulted in significantly elevated disease severity index scores, increased rectal bleeding and degree of colon shortening whereas, low Flii expression decreased disease severity, reduced tissue inflammation and improved clinical indicators of UC. Mice with high levels of Flii had significantly increased histological disease severity and elevated mucosal damage with significantly increased inflammatory cell infiltrate and significantly higher levels of TNF-α, IFN-γ, IL-5 and IL-13 pro-inflammatory cytokines. Additionally, Flii overexpression resulted in decreased β-catenin levels, inhibited Wnt/β-catenin signalling and impaired regeneration of colonic crypts. These studies suggest that high levels of Flii, as is observed in patients with UC, may adversely affect mucosal healing via mechanisms involving Th1 and Th2 mediated tissue inflammation and Wnt/β-catenin signalling pathway.

Recombinant invasive Lactobacillus plantarum expressing fibronectin binding protein A induce specific humoral immune response by stimulating differentiation of dendritic cells

Recombinant lactic acid bacteria (LAB), especially Lactococcus lactis, have been genetically engineered to express heterogeneous invasion proteins, such as the fibronectin binding protein A (FnBPA) from Staphylococcus aureus, to increase the invasion ability of the host strains, indicating a promising approach for DNA vaccine delivery. The presence of FnBPA has been also shown to be an adjuvant for co-delivered antigens, however, the underlying mechanisms are still not clear. To explore the above underlying mechanisms, in this study, we constructed a novel Lactobacillus plantarum strain with surface displayed FnBPA, which could significantly improve the adhesion and invasion ratios of L. plantarum strain on a porcine intestinal epithelial cell line (IPEC-J2) about two-fold compared with the empty vector. At the same time, the presence of FnBPA significantly stimulated the differentiation of bone marrow-derived dendritic cells (DCs) and increased the secretion of interleukin (IL)-6 and mRNA level of IL-6 gene, which were proved by flow cytometry, enzyme-linked immunosorbent assay (ELISA) and quantitative reverse transcription PCR (qRT-PCR). With regard to in vivo study, the presence of FnBPA significantly stimulated the differentiation of DCs in the Peyer's patch (PP) and the percentages of IL-4⁺ and IL-17A⁺ T helper (Th) cells of splenocytes in flow cytometry assay. In consistent with these results, the levels of IL-4 and IL-17A in serum as measured via ELISA also increased in mice treated with FnBPA⁺ L. plantarum. Finally, the FnBPA strain increased the production of B220⁺ B cells in mesenteric lymph node (MLN) and PP and the levels of FnBPA-specific IgG and sIgA antibodies, indicating the its possible application in vaccine field. This study demonstrated that the invasive L. plantarum with surface displayed FnBPA could modulate host immune response by stimulating the differentiation of DCs and Th cells which could possibly be responsive for the adjuvant effects of FnBPA.