Construction and in vitro evaluation of an LNP system for mRNA delivery / 药学实践杂志

Objective To construct lipid nanoparticles DLin-LNP for mRNA delivery. Methods DLin-LNP was prepared by thin film hydration method, and DLin-LNP/mRNA was further constructed by using EGFP-mRNA as model drug. The particle size, zeta potential, and appearance morphology were measured. Furthermore, the intracellular distribution and transfection of DLin-LNP/mRNA in RM-1 cells was investigated by laser scanning confocal microscope. Results DLin-LNP was successfully prepared. The average particle size was about (151.1±2.1) nm, the no-load potential was (23.7±0.5) mV. The cytotoxicity of DLin-LNP was far lower than that of the commercially available liposomal Lipo8000. The results of transfection experiment indicated that DLin-LNP has high transfection efficiency for mRNA delivery with low cytotoxicity and good stability. Conclusion DLin-LNP could become a potential mRNA vector for gene therapy.

Twelve-month specific IgG response to SARS-CoV-2 receptor-binding domain among COVID-19 convalescent plasma donors in Wuhan

To investigate the duration of humoral immune response in convalescent coronavirus disease 2019 (COVID-19) patients, we conduct a 12-month longitudinal study through collecting a total of 1,782 plasma samples from 869 convalescent plasma donors in Wuhan, China and test specific antibody responses. The results show that positive rate of IgG antibody against receptor-binding domain of spike protein (RBD-IgG) to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the COVID-19 convalescent plasma donors exceeded 70% for 12 months post diagnosis. The level of RBD-IgG decreases with time, with the titer stabilizing at 64.3% of the initial level by the 9th month. Moreover, male plasma donors produce more RBD-IgG than female, and age of the patients positively correlates with the RBD-IgG titer. A strong positive correlation between RBD-IgG and neutralizing antibody titers is also identified. These results facilitate our understanding of SARS-CoV-2-induced immune memory to promote vaccine and therapy development.

Research into the intervention effect of folic acid on arsenic-induced heart abnormalities in fetal rats during the periconception period.

BACKGROUND: The incidence of CHD is the highest among birth defects and is increasing year to year. CHD seriously harms the health of infants and young children and presents a large economic burden to families and society. The pathogenesis of CHD and preventive measures are the focus of current research. Our research aimed to explore the intervention effect of folic acid on heart abnormalities resulting from sodium arsenic (NaAsO2) exposure during the periconception period. METHODS: Sixty 35-day-old female SD rats were randomly divided into 5 groups with 12 rats in each group. Group A was the control group. The rats were given distilled water and ordinary chow. The rats in group B were given distilled water containing 75 mg/L NaAsO2 and ordinary chow. The rats in groups C, D, and E were given distilled water containing 75 mg/L NaAsO2 and chow containing 0.53 mg/kg, 5.3 mg/kg, and 10.6 mg/kg folic acid, respectively. The general condition of the embryos and the histopathology of the embryonic hearts were examined. The acetylation levels of histone H3K9 in heart tissues and the expression levels of Mef2C (which is related to heart development) were observed. RESULTS: The embryo weight and placental weight of groups B-E were significantly lower than those of group A (P < 0.05). The heart malformation rate of the fetal rats in groups B-E was significantly higher than that of the fetal rats in group A (P < 0.05). We found that the level of H3K9 acetylation in fetal rat cardiomyocytes in groups B-E was significantly higher than that in group A (P < 0.05) and that the level of H3K9 acetylation in groups C-E was lower than that in group B (P < 0.05). The mRNA level of Mef2C in fetal rat cardiomyocytes in group B-E was significantly higher than that in group A (P < 0.05), and the mRNA level of Mef2C in groups C-E was significantly lower than that in group B (P < 0.05). CONCLUSION: Supplementation with folic acid during the periconception period can interfere with the toxic effects of arsenic on the heart. The mechanism may be that lowering the acetylation levels of histone H3K9 in heart tissues leads to decreased expression levels of Mef2C, which may play a protective role in heart development in fetal rats.

Analysis of Peripheral B Cell Subsets in Patients With Allergic Rhinitis

PURPOSE: Recent evidence suggests that B cells can both promote and inhibit the development and progression of allergic disease. However, the characteristics of B cell subsets in patients with allergic rhinitis (AR) have not been well documented. This study aimed to analyze the characteristics of B cell subsets in the peripheral blood of AR patients. METHODS: Forty-seven AR patients and 54 healthy controls were enrolled in this study, and the B cell subsets in peripheral blood of all subjects were analyzed by flow cytometry. Moreover, the serum total immunoglobulin E (IgE) and IgE concentrations secreted into the cultured peripheral blood mononuclear cells (PBMCs) were measured by using enzyme-linked immunosorbent assay. RESULTS: We found the peripheral blood of AR patients contained higher percentages of memory B cells, plasma cells, and CD19+CD24hiCD27+ regulatory B cells (Bregs) than those of age-matched healthy controls (P < 0.05), while the percentages of naïve B cells and CD19+CD24hiCD38hi Bregs were significantly lower in AR patients than in healthy individuals (P < 0.05). In addition, the serum total IgE and IgE concentrations secreted into the cultured PBMCs were elevated in AR patients than in the healthy controls (P < 0.05). CONCLUSIONS: Our findings indicate that AR patients were characterized by increase in terminally differentiated memory B cells or plasma cells and decreases in CD19+CD24hiCD38hi Breg cells in the peripheral blood.

Analysis of relevant factors for recurrence of ovarian endometriosis after conservative laparoscopic surgery / 中南大学学报(医学版)

OBJECTIVE@#To analyze relevant factors for recurrence of ovarian endometriosis after conservative surgery.
@*METHODS@#A cohort study was performed on 310 patients who had performed conservative surgery for ovarian endometriosis. All patients underwent clinical interview. The relevant factors included: age at surgery, clinical symptom and signs, medical history, gynecologic examination, preoperative gravidity, complication, adenomyosis, American Society for Reproductive Medicine (ASRM) scores, post-operative drug therapy, post-operative gravidity and so on. The logistic regression analysis was performed to determine the predictive factors for recurrence of endometriosis.
@*RESULTS@#The relevant factors by univariate analysis were determined. The history of endometriosis surgery, history of intrauterine operation, tenderness nodule at cal-de-sal, bilateral endometrioma, multilocular cyst, intraoperative ASRM scores, complication of adenomyosis and operation time were the risk factors; whereas pre- and post-operative gravidity, post-operative drug therapy, and age at surgery were the protective factors. Meanwhile, the relevant factors by multivariate analysis were also confirmed. The history of endometriosis surgery, history of intrauterine operation, tenderness nodule at cal-de-sal, bilateral endometrioma, multilocular cyst, and intraoperative ASRM scores were the risk factors; whereas post-operative gravidity, post-operative drug therapy, pre-operative gravidity, and age at surgery were the protective factors.
@*CONCLUSION@#The risk factors for recurrence of ovarian endometriosis are history of endometriosis surgery, history of intrauterine operation, tenderness nodule at cal-de-sal, bilateral endometrioma, multilocular cyst, intraoperative ASRM scores, whereas the protective factors are pre- and post-operative gravidity, post-operative drug therapy and age at surgery.

Targeted interruption of COX-2 gene by siRNA inhibits the expression of VEGF, MMP-9, the activity of COX-2 and stimulates the apoptosis in eutopic, ectopic endometrial stromal cells of women with endometriosis / 中华妇产科杂志

Objective To investigate the effect of targeted interruption of cyclooxygenase-2 (COX-2) gene by small interference RNA (siRNA) on the expression of COX-2, vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) in eutopic and ectopic endometrial stromal cells (ESC) with endometriosis, and the effect on the content of 6-keto-prostaglandin-F1α (6-keto-PGF1α, metabolites of COX) and the apoptosis of eutopic and ectopic ESC with endometriosis. Methods Ectopic and eutopic ESC from 30 women with endometriosis were isolated and cultured respectively. Then, ESC were classified into three groups: interference group, negative control group and blank control group. ESC in interference group were injected into siRNA transfection complex while ESC in negative control group were injected into negative control transfection complex. ESC from 10 participants without endometriosis were the normal control group. The mRNA and protein expression of COX-2, VEGF, MMP-9 in pre-transfected and post-transfected eutopic and ectopic ESC were detected through real time reverse transcription PCR and western blot. The content of 6-keto-PGF1α was determined by ELISA, the apoptotic cells were detected by flow cytometry. Results After interruption of COX-2 gene, there were no significant difference in the mRNA and protein expression of COX-2, VEGF and MMP-9 between the negative control group and blank control group (P>0.05); the mRNA and protein expression of the three genes in interference group were significantly lower than those in negative control group and blank control group (P0.05);compared with those of negative control group and blank control group, the content of 6-keto-PGF1αin interference group decreased significantly (P0.05). The results from flow cytometry displayed that, there was no significant difference in apoptotic cells between the negative control group and blank control group (P>0.05);compared with those of negative control group and blank control group, more apoptotic cells were detected in interference group and the difference was significant (P<0.01);the apoptotic cells in ectopic ESC were significantly more than that in eutopic ESC (P<0.05); the apoptosis rate in interference group of eutopic and ectopic ESC were (33.76 ± 0.06)%, (47.18 ± 0.12)%. Conclusions Our results suggested the targeted interruption of COX-2 gene by siRNA effectively inhibited the mRNA and protein expression of COX-2, VEGF and MMP-9 in both eutopic ESC and ectopic ESC with endometriosis, greatly increased the apoptotic rate of cells and obviously reduced the content of 6-keto-PGF1αby inhibiting the activity of COX-2. And the changes in ectopic endometrium were more evident than those in eutopic endometrium.