Effects of clostridium butyricum and bifidobacterium on BTLA expression on CD4+ T cells and lymphocyte differentiation in late preterm infants.

BACKGROUND & AIMS: Probiotics is recognized to promote growth performance and immune function via balancing the intestinal microflora. Live clostridium butyricum and bifidobacterium combined powder (LCBBCP) has been widely to treat intestinal dysbacteriosis in newborns in China. This study was undertaken to investigate the effects of the combined probiotics on the expression of B and T lymphocyte attenuator (BTLA) on CD4+ T cells and the differentiation of lymphocyte subsets in late preterm infants. METHODS: Eighty eligible late preterm infants were equally randomized into LCBBCP therapy group (oral LCBBCP dissolved in formula milk before intake) and control group (treated with simple formula milk for preterm infants) by random digit table. Flow cytometry was used to determine the expression level of BTLA on CD4+ T cells and the percentage of individual subpopulation of lymphocytes in peripheral-blood mononuclear cells (PBMCs) obtained from the late preterm infants in both groups. RESULTS: BTLA protein expression on CD4+ T cells showed no significant change in LCBBCP therapy group before and after intervention, yet was rapidly and significantly down-regulated in the controls. The percentage of increased CD4+ T cells, decreased CD8+ T cells and increased ratio of CD4+/CD8+ T cell proportion were seen in both groups after treatment, yet the increasing or decreasing extent in LCBBCP therapy group was more obvious than in control group. The proportion of NK cells and B lymphocytes remained no significant difference between the two groups before and after therapy. CONCLUSIONS: LCBBCP appears capable of facilitating the activation, proliferation and differentiation of T lymphocytes, which is beneficial to improving immunity in late preterm infants. The continuous high expression of BTLA on CD4+ T cells in LCBBCP therapy group may be involved in the inhibiting of excessive activation of T lymphocytes. Our findings may lay a basis for further clinical evaluation of the efficacies and wider clinical recommendation of probiotics containing live clostridium butyricum and bifidobacterium for late preterm infants.

[The study of hydrogen peroxide induced DNA damage and recovery in normal aging and premature aging human cells].

OBJECTIVE: To study the DNA damage and recovery induced by hydrogen peroxide in normal aging and premature aging human cells. METHODS: The immunofluorescent assay and comet assay were used to estimate basal DNA damage in normal aging BJ cells and premature aging Hutchinson-Gilford progeria syndrome (HGPS) cells, which were divided into three and two distinct population doubling (PD) number groups (BJ 14, 30, 45 and HGPS 8, 17) respectively. The DNA damage induced by hydrogen peroxide of these cell populations, as well as their repair activity, was also studied. Finally, the recovery capability before and after the xeroderma pigmentosum group A (XPA) knocked down in these groups was measured. RESULTS: Our results indicated that the normal BJ cells of older PD number showed higher basal levels of DNA damage and were more sensitive to the effects of the DNA-damaging agents than the adult one, who, in turn, was more sensitive than the younger ones. The basal damage level of HGPS cells was same or higher than the older BJ cells. HGPS cells also had the same consistent damage change as BJ cells after treatment. The decline of the repair efficiency with age to the DNA damage induced by the agent was also observed. CONCLUSION: The DNA repair of HGPS is repressed by dysfunction of XPA.

[Quercetin permeability across blood-brain barrier and its effect on the viability of U251 cells].

OBJECTIVE: To investigate the permeability of quercetin across blood-brain barrier (BBB) and its impact on the proliferation and apoptosis of U251 cells. METHODS: The BBB model was established through culture of primary brain microvessel endothelial cells (BMVEC) and primary astroglia cells (AC), which was confirmed by transmission electron microscopy (TEM) and trans epithelial electric resistance (TEER). High pressure liquid chromatography (HPLC) was performed to determine quercetin permeability across BBB. U251 cells were exposed to quercetin. MTT assay, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), single-cell gel electrophoresis (SCGE) and flow cytometry (FCM) were performed to analyze cell proliferation, apoptosis, DNA damage and cell cycle distribution. RESULTS: The BBB was constructed successfully. Up to 65.54% of quercetin permeated across the BBB. Quercetin attenuated the proliferation of U251 and induced apoptosis. The FCM revealed that the U251 cells were inhibited at the G2/M point. CONCLUSION: Quercetin can permeate across the BBB effectively, restraining the proliferation of U251 cells and inducing apoptosis.

Association of long non-coding RNA GAS5 and miR-21 levels in CD4+ T cells with clinical features of systemic lupus erythematosus.

The present study aimed to assess the expression of growth arrest-specific 5 (GAS5) and microRNA (miR)-21 in systemic lupus erythematosus (SLE), and attempted to explore their association with clinical features. CD4+ T cells were isolated from peripheral blood of healthy donors and SLE patients by magnetic-activated cell sorting. GAS5 and miR-21 expression levels in cluster of differentiation (CD)4+ T cells were measured by reverse-transcription quantitative polymerase chain reaction. The results revealed that GAS5 and miR-21 levels were significantly elevated in CD4+ T cells of patients with SLE compared with those in control subjects (P<0.05). Regarding clinical features, SLE patients with ulceration had higher GAS5 expression levels in CD4+ T cells than those without ulceration (P<0.05), and the expression of miR-21 was significantly higher in CD4+ T cells of SLE patients with low levels of complement component 3 (C3) than in those with normal levels of complement C3 (P<0.05). In conclusion, GAS5 and miR-21 in CD4+ T cells may serve as potential biomarkers for the diagnosis and monitoring of the progression of SLE.