Involvement of retinoic acid receptor α in the autistic-like behavior of rats with vitamin A deficiency by regulating neurexin 1 in the visual cortex: a mechanism study

OBJECTIVES

To study the mechanism of retinoic acid receptor α (RARα) signal change to regulate neurexin 1 (NRXN1) in the visual cortex and participate in the autistic-like behavior in rats with vitamin A deficiency (VAD).

METHODS

The models of vitamin A normal (VAN) and VAD pregnant rats were established, and some VAD maternal and offspring rats were given vitamin A supplement (VAS) in the early postnatal period. Behavioral tests were performed on 20 offspring rats in each group at the age of 6 weeks. The three-chamber test and the open-field test were used to observe social behavior and repetitive stereotyped behavior. High-performance liquid chromatography was used to measure the serum level of retinol in the offspring rats in each group. Electrophysiological experiments were used to measure the long-term potentiation (LTP) level of the visual cortex in the offspring rats. Quantitative real-time PCR and Western blot were used to measure the expression levels of RARα, NRXN1, and N-methyl-D-aspartate receptor 1 (NMDAR1). Chromatin co-immunoprecipitation was used to measure the enrichment of RARα transcription factor in the promoter region of the NRXN1 gene.

RESULTS

The offspring rats in the VAD group had autistic-like behaviors such as impaired social interactions and repetitive stereotypical behaviors, and VAS started immediately after birth improved most of the behavioral deficits in offspring rats. The offspring rats in the VAD group had a significantly lower serum level of retinol than those in the VAN and VAS groups (P<0.05). Compared with the offspring rats in the VAN and VAS groups, the offspring rats in the VAD group had significant reductions in the mRNA and protein expression levels of NMDAR1, RARα, and NRXN1 and the LTP level of the visual cortex (P<0.05). The offspring rats in the VAD group had a significant reduction in the enrichment of RARα transcription factor in the promoter region of the NRXN1 gene in the visual cortex compared with those in the VAN and VAS groups (P<0.05).

CONCLUSIONS

RARα affects the synaptic plasticity of the visual cortex in VAD rats by regulating NRXN1, thereby participating in the formation of autistic-like behaviors in VAD rats.

[Hyperoside protects mouse spermatocytes GC-2 cells from oxidative damage by activating the Keap1/Nrf2/HO-1 pathway]

OBJECTIVE

To study the protective effect of hyperoside (Hyp) against ydrogen peroxide (H2O2)- induced oxidative damage in mouse spermatocytes GC-2 cells and explore the role of the Keap1/Nrf2/HO-1 pathway in this protective mechanism.

METHODS

GC-2 cells were treated with 2.5 mmol/L azaacetylcysteine (NAC), 50, 100, and 200 μmol/L hyperoside, or the culture medium for 48 h before exposure to H2O2 (150 μmol/L) for 2 h. CCK-8 assay was used to detect the changes in cell viability, and cell apoptosis was analyzed using flow cytometry. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), catalase (CAT) activity and malondialdehyde (MDA) in the culture medium. Western blotting and RT-qPCR were used to detect the protein and mRNA expression levels of nuclear factor erythroid 2-related factor2 (Nrf2), Kelch-like ECH-associated protein 1 (Keap1), and heme oxygenase-1 (HO-1); the nuclear translocation of Nrf2 was detected using immunofluorescence assay.

RESULTS

Exposure to H2O2 significantly lowered the proliferation rate, reduced the activities of SOD, GSH and CAT, and obviously increased MDA content, cell apoptosis rate, and the expressions of Keap1 and Nrf2 mRNA and Keap1 protein in GC-2 cells (P < 0.05 or 0.01). Treatment of the cells prior to H2O2 exposure with either NAC or 200 μmol/L hyperoside significantly increased the cell proliferation rate, enhanced the activities of SOD, GSH-PX and CAT, and lowered MDA content and cell apoptosis rate (P < 0.05). Treatment with 200 μmol/L hyperoside significantly decreased the mRNA and protein expressions of Keap1 and increased the expressions of HO-1 mRNA and the protein expressions of Nrf2 and HO-1 (P < 0.05 or 0.01). Hyperoside also caused obvious nuclear translocation of Nrf2 in the cells (P < 0.05).

CONCLUSION

Hyperoside protects GC-2 cells against H2O2- induced oxidative damage possibly by activation of the Keap1/Nrf2/HO-1 signaling pathway.

[Extranuclear p53 suppresses autophagy through AMPK/mTOR signaling to promote heat stress-induced vascular endothelial cell damage]

OBJECTIVE

To explore the role of extranuclear p53-mediated autophagy suppression by regulating AMPK/mTOR signaling pathway in heat stress (HS)-induced injury of mouse aortic endothelial cells (MAECs).

METHODS

Primary cultures of MAECs were pretreated with compound C (an AMPK inhibitor), rapamycin (a mTOR inhibitor) or pifithrin-α (PFT, a selective p53 inhibitor) for 1 h before exposure to HS (43 ℃) for 2 h. The changes in cell viability at different time points after HS were examined using CCK-8 assay, and the protein expressions of P53, LC3-II, Beclin-1, p62 and the AMPK/mTOR signaling proteins were detected using Western blotting. In the animal experiment, C57 mice were pretreated with compound C, rapamycin or PFT and exposed to a high temperature at 40 ℃ to induce HS. The pathological changes in the aorta of the mice were observed with HE staining, and cell apoptosis was detected using TUNEL staining.

RESULTS

In cultured MAECs, the cell viability was significantly reduced (P < 0.05) and the mitochondrial fraction of p53 increased while its cytoplasmic fraction decreased progressively over time following HS. HS significantly lowered the expressions of LC3-II and Beclin-1, increased p62 level, suppressed AMPK phosphorylation, and increased mTOR phosphorylation and the expressions of its downstream proteins at 6 h after the exposure (P < 0.05). Pretreatment with compound C significantly inhibited LC3-II and Beclin- 1 expression, enhanced p62 expression, and aggravated HS-induced cell injury and apoptosis in MAECs; rapamycin treatment produced the opposite effects (P < 0.05). PFT treatment significantly enhanced the viability of MAECs and alleviated HSinduced injury and apoptosis; PFT also significantly promoted activation of AMPK phosphorylation, inhibited mTOR phosphorylation and its downstream proteins (P < 0.05), enhanced the expressions of LC3-II and Beclin 1, and inhibited p62 expression in the MAECs (P < 0.05). In C57 mice, HS resulted in swelling, shedding and apoptosis of aortic vascular endothelial cells. Pretreatment with compound C obviously aggravated HS-induced vascular injury and endothelial cell apoptosis, while pretreatment with either rapamycin or PFT significantly alleviated these injuries.

CONCLUSION

Autophagy inhibition mediated by extranuclear p53 via inhibiting AMPK activity and activating mTOR signaling participates in HS-induced injury of MAECs.

[Fetal malnutrition assessment program]

OBJECTIVE

To study the application of ponderal index (PI), body mass index (BMI), mid-arm circumference/head circumference (MAC/HC), and Clinical Assessment of Nutritional Status (CANS) score in assessing the nutritional status of neonates at birth, and to find a simple and reliable scheme for the assessment of fetal nutritional status.

METHODS

PI, BMI, MAC/HC, and CANS were used to assess the nutritional status of full-term infants and preterm infants shortly after birth. The assessment results of these methods were analyzed.

RESULTS

Among the 678 full-term infants, 61, 102, 47, and 131 were diagnosed with malnutrition by PI, BMI, MAC/HC, and CANS respectively. Among the 140 preterm infants, 30, 87, 9, and 112 were diagnosed with malnutrition by PI, BMI, MAC/HC, and CANS respectively. The combination of BMI and CANS had a detection rate of 99.3% in full-term infants and 100% in preterm infants. Compared with the single method, the combination significantly improved the detection rate of malnutrition (P < 0.05), while there was no significant difference between the combination of BMI+CANS and the combination of PI+BMI+CANS (P > 0.05).

CONCLUSIONS

The combination of BMI+CANS can reduce the rate of missed diagnosis of fetal malnutrition. It is therefore a simple and reliable method for the assessment of fetal malnutrition.

[Influence of different mixing pads on physical and mechanical properties of glass ionomer cement]

OBJECTIVE

To analyze the influence of different mixing pads on the physical and mechanical properties of glass ionomer cement.

METHODS

Three different glass ionomer base cements were mixed with a plastic spatula on three different mixing pads including paper pad, glass pad and silicon pad whose HS were 40, 60 and 80. The GIC was packed into stainless steel molds to get specimens. Surface roughness, surface hardness and compressive strength were evaluated.

RESULTS

As for compressive strength, CF: There was the highest mean compressive strength that was significantly higher than those of silicon pad 60 group, paper 60 group and paper 20 group in silicon pad 40 group, the differences P values were 0.002, 0.027, and 0.036, statistically significant difference between the above groups (P<0.05). IX: there was the highest mean compressive strength that was significantly higher than those of silicon pad 60 group in paper pad 20 group,the differences P value was 0.008, statistically significant (P<0.05). FX: there was the highest mean compressive strength that was no significantly higher than those of paper pad 20 group in silicon pad 40 group, but was significantly higher than those of the other groups. As for surface hardness, CF: there was the highest mean surface hardness that was significantly higher than those of silicon pad 60 and 80 group, paper 60 group in silicon pad 40 group, the differences P value was 0.021, 0.001, 0.032, 0.008 and 0.016, statistically significant difference between the above groups (P<0.05). IX and FX: there was no statistical significance between any two groups in surface hardness. As for surface roughness, CF: there was no statistical significance between any two groups in surface roughness. IX: there was the lowest mean surface roughness that was significantly lower than those of paper pad 40 and 60 group in glass pad group, the differences P values were 0.003 and 0.027, statistically significant difference between the above groups (P<0.05). FX: there was the lowest mean surface roughness that was significantly lower than those of paper pad 60 group in glass pad group, the differences P value was 0.018, showing a statistical difference (P<0.05).

CONCLUSION

Mixing glass ionomer cement on silicon pad 40 results in higher compressive strength and lower surface roughness, worthy of clinical popularization.

[Influence of different mixing pads on physical and mechanical properties of glass ionomer cement]

OBJECTIVE

To analyze the influence of different mixing pads on the physical and mechanical properties of glass ionomer cement.

METHODS

Three different glass ionomer base cements were mixed with a plastic spatula on three different mixing pads including paper pad, glass pad and silicon pad whose HS were 40, 60 and 80. The GIC was packed into stainless steel molds to get specimens. Surface roughness, surface hardness and compressive strength were evaluated.

RESULTS

As for compressive strength, CF: There was the highest mean compressive strength that was significantly higher than those of silicon pad 60 group, paper 60 group and paper 20 group in silicon pad 40 group, the differences P values were 0.002, 0.027, and 0.036, statistically significant difference between the above groups (P<0.05). IX: there was the highest mean compressive strength that was significantly higher than those of silicon pad 60 group in paper pad 20 group,the differences P value was 0.008, statistically significant (P<0.05). FX: there was the highest mean compressive strength that was no significantly higher than those of paper pad 20 group in silicon pad 40 group, but was significantly higher than those of the other groups. As for surface hardness, CF: there was the highest mean surface hardness that was significantly higher than those of silicon pad 60 and 80 group, paper 60 group in silicon pad 40 group, the differences P value was 0.021, 0.001, 0.032, 0.008 and 0.016, statistically significant difference between the above groups (P<0.05). IX and FX: there was no statistical significance between any two groups in surface hardness. As for surface roughness, CF: there was no statistical significance between any two groups in surface roughness. IX: there was the lowest mean surface roughness that was significantly lower than those of paper pad 40 and 60 group in glass pad group, the differences P values were 0.003 and 0.027, statistically significant difference between the above groups (P<0.05). FX: there was the lowest mean surface roughness that was significantly lower than those of paper pad 60 group in glass pad group, the differences P value was 0.018, showing a statistical difference (P<0.05).

CONCLUSION

Mixing glass ionomer cement on silicon pad 40 results in higher compressive strength and lower surface roughness, worthy of clinical popularization.

[Predictive value of miRNA-29a and miRNA-10a-5p for 28-day mortality in patients with sepsis-induced acute kidney injury]

OBJECTIVE

To investigate the value of miR-29a and miR-10a-5p in predicting 28-day mortality in patients with sepsis-induced acute kidney injury.

METHODS

Seventy-four patients with sepsis-induced acute kidney injury (AKI) and 41 patients with sepsis but without AKI (control) were examined for serum levels of miR-29a and miR-10a-5p using RT-PCR. The patients were followed up for 28 days to record their survival. Pearson correlation analysis was used to test the correlations of miR-29a and miR-10a-5p with serum creatinine (Scr), cystatin C (Cys-C), and KIM-1 in patients with AKI. Multivariate logistic regression analysis was used to analyze the correlations of miR-29a, miR-10a-5p, Scr, Cys-C, KIM-1 and other risk factors with the 28-day mortality in patients with sepsis. The predictive value of these indicators for evaluating the prognosis of patients with sepsis was analyzed using ROC curve, and miR-29a combined with miR-10a-5p was assessed for their value in predicting the prognosis of the patients.

RESULT

During the follow-up for 28 days, 21 of the 74 (35.53%) AKI patients died. Compared with the survivors, the patients died within 28 days showed significantly increased serum levels of Scr , Cys-C, KIM-1, miR-29a, and miR-10a-5p (P<0.05). Pearson correlation analysis showed that miR-29a and miR-10a-5p were positively correlated with serum Scr, Cys-C, and KIM-1 levels; multivariate regression analysis identified miR-29a and miR-10a-5p as the independent risk factors for mortality in the septic patients. The ROC curve analysis showed that the area under the curve (AUC) of miR-29a and miR-10a-5p was 0.82 (95%CI: 0.71-0.89) and 0.75 (95%CI: 0.64-0.85), and that of Scr, Cys-C and KIM-1 was 0.72 (95%CI: 0.66-0.86) , 0.71 (95% CI: 0.63-0.84) and 0.81 (95% CI: 0.72-0.81), respectively. The AUC of miR-29a combined with miR-10a-5p was significantly greater than that of miR-29a, miR-10a-5p, Scr, Cys-C and KIM-1 alone (P<0.05).

CONCLUSION

miR-29a and miR-10a-5p have good predictive value in assessing the 28-day mortality of patients with sepsis.