[Prokaryotic expression and purification of antimicrobial peptide LL-37 and the inhibiting effect against Candida albicans]

OBJECTIVE

To study the inhibitory effect of antimicrobial peptide LL-37 on Candida albicans through its ability to promote the secretion of immune factors by vaginal epithelial cells.

METHODS

(1) LL-37 prokaryotic expression vector pET-Duet/LL-37 was constructed and its expression was induced in Escherichia coli M15. The expressed LL-37 fusion protein was purified and identified by western blot. Antifungal activity of the purified protein was initially identified by Kirby-Bauer (K-B) method. (2) Purified LL-37 protein was added to human vaginal epithelial cells co-cultured with Candida, and inhibitory effect on Candida growth was determined by the glucose consumption method. Interferon γ (IFN-γ), interleukin 10 (IL-10) concentration and IFN-γ/IL-10 ratio were measured by ELISA at different time points.

RESULTS

(1) LL-37 fusion protein was purified to 96% purity at a concentration of 433.92 μg/ml, and was shown to possess anti-fungal activity confirmed by the K-B method. (2) A Candida-vaginal epithelial cells co-culture system was successfully constructed. LL-37 recombinant protein inhibited the growth of Candida with absorbance values significantly higher in the treatment group compared to the control group at all measured time points (12-hour: 3.008±0.003 versus 2.967±0.003, 24-hour: 2.941±0.003 versus 2.601±0.003, 48-hour: 2.893 ± 0.004 versus 2.409 ± 0.003; all P<0.01). Furthermore, the rate of decrease was also much slower compared to the control group. In both control and experimental groups, IFN-γ and IL-10 secretion levels were observed to rise at first peaking at 24 hours and subsequently decrease. For each time period, IFN-γ concentration in the experimental group was significantly higher at 24 hours compared to the control group [(104.00 ± 1.07) versus (85.17 ± 0.28) pg/ml,P<0.01]. In contrast, IL-10 concentrations were significantly lower than the control group at all time points (P<0.01). IFN-γ/IL-10 ratio was also observed to be significantly higher than the control group at all measured time points (P<0.01).

CONCLUSIONS

(1) Recombinant protein LL-37 could significantly inhibit the growth of Candida. (2) By influencing the secretion of immune factors such as IFN-γ, IL-10, etc, recombinant protein LL-37 is able to adjust vaginal epithelial cells local immunity, and enhance resistance to Candida infection.

Association of Resting Heart Rate with Infrarenal Aortic Diameter: A Cross Sectional Study in Chinese Hypertensive Adults

OBJECTIVE

Elevated resting heart rate (RHR) has been shown to be a risk marker for cardiovascular disease. Results from studies on the effects of RHR in large arteries are limited to the functional changes of those arteries, while the association between RHR and aortic diameter remains largely understudied.

METHODS

This was a cross sectional study of hypertensive Chinese adults from rural areas. The maximum infrarenal aortic diameter (maxIAD) from renal arteries to the iliac bifurcation was obtained by ultrasound. MaxIADs in different RHR groups were compared in males and females separately because of the significant differences between sexes. Multiple regression analysis was used to determinate the correlation between RHR and maxIAD. Further interactions between three factors (BMI, smoking, and anti-hypertensive regimens) and RHR for maxIAD were examined using subgroup analysis.

RESULTS

19,200 subjects were enrolled in the study, with an average age of 64.8±7.4 years and 61.6% females. Only 22 cases (0.11%) were detected with AAA, with males (n = 17) presenting a higher AAA incidence than females (n = 5). In subjects ≥65 years, there were 18 (0.19%) AAA, and 15 (83.3%) had a history of smoking. In the total subjects, the mean maxIAD ranged from 15.7±2.1 mm to 15.2±2.2 mm as RHR changed from the lowest quartile to the highest (≥84 bpm) in males, with a similar tendency observed in females. The correlation coefficient of RHR on maxIAD was -0.17 in males and -0.12 in females. Further subgroup analysis revealed that smoking exaggerated the correlation between RHR and maxIAD, but only in females.

CONCLUSIONS

A low AAA incidence was observed in this hypertensive Chinese population. There was a negative association between RHR and maxIAD, potentially exaggerated by smoking, especially in females.

Sleep duration and snoring associate with hypertension and glycaemic control in patients with diabetes

AIMS

Few studies have analysed the effect of sleep duration and snoring on hypertension and glycaemic control in patients with diabetes. This study aims to investigate the relationship of sleep duration and snoring on prevalent hypertension and glycaemic control in people with diabetes.

METHODS

In the baseline survey of the REACTION study, 56 032 patients with diabetes were categorized into four groups according to self-reported sleep duration: < 6, 6-7.9, 8-8.9 and ≥ 9 h. Snoring frequency was evaluated as 'usually', 'occasionally' or 'never'. Hypertension was assessed by systolic blood pressure, diastolic blood pressure, self-reported previous diagnosis and antihypertensive medications. 'Good' glycaemic control was defined as HbA1c < 53 mmol/mol (7.0%) and 'poor' glycaemic control as HbA1c ≥ 53 mmol/mol (7.0%).

RESULTS

Controlling for potential confounders and intermediates, sleep ≥ 9 h relative to intermediate sleep (6-7.9 h) was significantly associated with prevalent hypertension (OR: 1.25, 95% CI: 1.18-1.32) and poor glycaemic control (OR: 1.11, 95% CI: 1.05-1.18), and a U-shaped association was found between sleep duration and prevalent hypertension (P for quadratic trend = 0.019). Usually snoring was positively associated with prevalent hypertension (OR: 1.30, 95% CI: 1.23-1.37), whereas the association between snoring and poor glycaemic control was only on the borderline of statistical significance.

CONCLUSIONS

Compared with a sleep duration of 6-7.9 h, longer sleep duration was associated with a higher prevalence of hypertension and poor glycaemic control in people with diabetes. Moreover, the relationship between sleep duration and prevalent hypertension was U-shaped. These findings may propose important public health implications for diabetes management.

MicroRNA-30b promotes axon outgrowth of retinal ganglion cells by inhibiting Semaphorin3A expression

Semaphorin3A (Sema3A) is a major inhibitory factor of optic nerve (ON) regeneration post-injury. Many microRNAs (miRNAs) are expressed specifically in the mammalian brain and retina and are dynamically regulated during development, suggesting that this group of miRNAs may be associated with neural development. We found that microRNA-30b (miR-30b) bound to the three prime untranslated region (3' UTR) of Sema3A and inhibited the expression of Sema3A mRNA. The mRNA expression level of miR-30b and the protein expression levels of Sema3A, Neuropilin1 (NRP1), PlexinA1 (PlexA1), phosphorylated p38MAPK (p-p38MAPK), and active caspase-3 were all upregulated in retinas from rats with a damaged ON relative to those with an intact ON. Transfection of cultured retinal ganglion cells (RGCs) with an miR-30b mimic led to decreased levels of Sema3A, NRP1, PlexA1, p-p38MAPK, and active caspase-3 protein expression, as well as axon elongation and reduced levels of apoptosis. These findings provide evidence that miR-30b inhibits Sema3A expression. Decreased Sema3A expression promotes axon outgrowth in RGCs due to reduced levels of Sema3A binding to NRP1 and PlexA1 and simultaneously reduces apoptosis by inhibiting the p38MAPK and caspase-3 pathways. Our findings provide the first evidence that miR-30b-mediated Sema3A downregulation may serve as a new strategy for the clinical treatment of ON injury.

Plasma levels and placental expression of vaspin in pregnant women with diabetes mellitus

The present study aimed to investigate visceral adipose tissue-specific serpin (vaspin) concentrations in serum and term placentas and relate these values to insulin resistance and lipid parameters in women with gestational diabetes mellitus (GDM). A total of 30 GDM subjects and 27 age-matched pregnant women with normal glucose tolerance (NGT, control) were included. Serum glucose, glycated hemoglobin (HbA1c), lipid profile, insulin, and vaspin were measured at the end of pregnancy, and homeostasis model of assessment-insulin resistance (HOMA-IR) values were calculated. Vaspin mRNA and protein levels in placentas were measured by real-time fluorescence quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blotting, respectively. Serum vaspin levels were significantly lower in the GDM group than in controls (0.49±0.24 vs 0.83±0.27 ng/mL, respectively; P<0.01). Three days after delivery, serum vaspin levels were significantly decreased in subjects with GDM (0.36±0.13 vs 0.49±0.24 ng/mL, P<0.01). However, in the GDM group, serum vaspin levels were not correlated with the parameters evaluated. In contrast, in the control group, serum vaspin levels were positively correlated with triglycerides (TG; r=0.45, P=0.02) and very low-density lipoprotein cholesterol (VLDL-C; r=0.42, P=0.03). Placental mRNA vaspin (0.60±0.32 vs 0.68±0.32, P=0.46) and protein (0.30±0.08 vs 0.39±0.26; P=0.33) levels in the GDM group did not differ significantly from those in the control group, but were negatively correlated with neonatal birth weight in the GDM group (r=-0.48, P=0.03; r=-0.88; P<0.01). Our findings indicated that vaspin may be an important adipokine involved in carbohydrate and lipid metabolism and may also play a role in fetal development.

[Comparison of angiography-guided and fractional flow reserve-guided management strategy of percutaneous coronary intervention for intermediate coronary lesions]

OBJECTIVE

To compare the consistency of angiography-guided and fractional flow reserve (FFR)-guided management strategy for intermediate coronary lesions.

METHODS

The patients whose coronary intermediate lesions were assessed by measuring FFR from November 2012 to August 2014. The stenosis percentage and value of FFR during the procedure were collected. All the image data were collected and four experienced interventional cardiologists were invited to assess the target lesions and make a management strategy independently. The consistency of angiography-guided and fractional flow reserve-guided management strategy were analyzed.

RESULTS

In the study, 151 patients were included, of whom, 70.2% were male, the average age was (62.7±9.6) years, 169 vessels were assessed by measuring FFR, 1 being left main, 116 left anterior descending, 27 left circumflex branch, and 25 right coronary artery. There were some correlationship between the stenosis percentage judged by four interventional cardiologists and the stenosis percentage judged during the procedure (r=0.29-0.38, P<0.001), but the difference was significant. When 0.80 was used as FFR threshold value, the consistency rates of angiography-guided management strategy decision made by the four cardiologists with fractional flow reserve-guided management strategy were 72.78%, 71.60%, 75.15%, and 72.78%, respectively.

CONCLUSION

Angiography-guided management strategy decision is unreliable, FFR is recommended for management strategy decision for intermediate coronary lesions.

Association of Carotid Intima-media Thickness and Atherosclerotic Plaque with Periodontal Status

Studies have suggested an association between clinical/subclinical atherosclerosis and periodontal status. The purpose of this study was to investigate the association among maximal carotid intima-media thickness (cIMT), atherosclerotic plaque, and periodontal status in Chinese elderly patients. A cross-sectional study was conducted of 847 participants (age, 70.64 ± 9.03 yr) with ≥10 teeth. A questionnaire survey, routine biochemical tests, a periodontal examination, and maximal cIMT measurement were performed for each. Traditional risk factors for atherogenesis were considered in the statistical analysis. Mean plaque index, which reflects oral hygiene, was correlated with maximal cIMT and atherosclerotic plaque in the study sample overall (β = 0.068, p < .001; OR = 2.051, p < .001) and in euglycemic participants (β = 0.066, p = .008; odds ratio = 2.122, p = .009). In hyperglycemic participants, multiple linear regression analysis (p = .006) and multivariate logistic regression analysis (p = .025) revealed a linear and dose-dependent association between mean clinical attachment loss and maximal cIMT after adjustment for traditional risk factors. Each 1-mm increase in mean clinical attachment loss corresponded to a 0.018-mm increase in maximal cIMT. The risk of atherosclerotic plaque increased by 18.3% with each 1-mm increase in mean clinical attachment loss. Other indicators of periodontal exposure, including percentage of sites with attachment loss ≥ 3 to 5 mm (3%-5%), were also correlated with cIMT and atherosclerotic plaque in hyperglycemic patients. In this elderly population, a linear and dose-dependent association among mean clinical attachment loss, attachment loss 3% to 5%, maximal cIMT, and atherosclerotic plaque was verified in those with hyperglycemia. Poor oral hygiene was correlated with maximal cIMT and atherosclerotic plaque in all participants, including those with normal blood glucose.

Percentage of circulating CD8+ T lymphocytes is associated with albuminuria in type 2 diabetes mellitus

T lymphocytes have been demonstrated to play a role in the development of diabetic proteinuria. However, the alteration of circulating T lymphocytes has not been investigated in a type 2 diabetic cohort. A cross-sectional study was conducted in Peking University Aerospace Center Hospital. 510 participants were type 2 diabetes mellitus, 30-70 years of age. Patients with immune disease, medical conditions that affect immune function, infection, or end-organ damage were excluded. The percentage of circulating CD8+ T lymphocytes was significantly associated with albuminuria in the cohort. The impact of albuminuria to CD8+ T lymphocytes in a multivariate linear regression model was indicated by the B- coefficient (95% confidence interval) 1.812 (0.204-3.421, P=0.03). Our data first showed that the percentage of circulating CD8+ T cells is associated with albuminuria in type 2 diabetes mellitus, which may support the rationality of systemic inhibition of T lymphocytes in treating albuminuria in these patients.