[Mutation of nuclear autoantigenic sperm protein (NASP) gene aggravates autoimmune response in induced lupus model mice].

Objective To prepare inducible lupus model mice and investigate the effect of nuclear autoantigenic sperm protein (NASP) gene mutation on the autoimmune response of mice with induced systemic lupus erythematosus (SLE). Methods The 3-month wild-type B6 (B6-WT) mice were used as a control group and the NASP mutant B6 (B6-NASPM) mice as an experimental group. Mouse spleen lymphocytes were activated with concanavalin A (ConA), and the DNA was extracted as autoantigen. B6-WT mice and B6-NASPM mice were immunized three times. Serum anti-double stranded DNA (dsDNA) IgG levels were detected by ELISA. Renal lesions were detected by HE staining. Immunohistochemical staining was performed to detect the deposition of IgG and complement C3 in the renal tissues. Flow cytometry was applied to compare the spleen lymphocyte subsets in B6-WT and B6-NASPM mice and to explore the mechanism of NASP gene mutation affecting the immune response in mice. Results Compared with B6-WT mice, B6-NASPM mice showed no significant changes in body weight, kidney index and spleen index; serum anti-dsDNA IgG levels significantly increased; glomerular cell proliferation was obvious and the deposition of IgG and C3 in the renal tissues increased. The proportion of spleen CD3+ T cells and natural killer (NK) cells decreased, while the proportion of CD19+ B cells and regulatory B cells (Breg) increased. Conclusion Mutation in the NASP gene can increase the levels of anti-dsDNA IgG antibodies, promote cell proliferation in the glomerulus of the kidney, deposition of IgG antibodies and complement C3, alter the proportion of immune cells in the spleen and aggravate the autoimmune response in lupus model mice.

The correlationship between the metabolizable energy content, chemical composition and color score in different sources of corn DDGS.

BACKGROUND: This study was conducted to evaluate the apparent metabolizable energy (AME) and true metabolizable energy (TME) contents in 30 sources of corn distillers dried grains with solubles (DDGS) in adult roosters, and establish the prediction equations to estimate the AME and TME value based on its chemical composition and color score. METHODS: Twenty-eight sources of corn DDGS made from several processing plants in 11 provinces of China and others imported from the United States. DDGS were analyzed for their metabolizable energy (ME) contents, measured for color score and chemical composition (crude protein, crude fat, ash, neutral detergent fiber, acid detergent fiber), to predict the equation of ME in DDGS. A precision-fed rooster assay was used, each DDGS sample was tube fed (50 g) to adult roosters. The experiment was conducted as a randomized incomplete block design with 3 periods. Ninety-five adult roosters were used in each period, with 90 being fed the DDGS samples and 5 being fasted to estimate basal endogenous energy losses. RESULTS: Results showed that the AME ranged from 5.93 to 12.19 MJ/kg, TME ranged from 7.28 to 13.54 MJ/kg. Correlations were found between ME and ash content (-0.64, P < 0.01) and between ME and yellowness score (0.39, P < 0.05) of the DDGS samples. Furthermore, the best-fit regression equation for AME content of DDGS based on chemical composition and color score was AME = 6.57111 + 0.51475 GE - 0.10003 NDF + 0.13380 ADF + 0.07057 fat - 0.57029 ash - 0.02437 L (R2 = 0.70). The best-fit regression equation for TME content of DDGS was TME = 7.92283 + 0.51475 GE - 0.10003 NDF + 0.13380 ADF + 0.07057 fat - 0.57029 ash - 0.02437 L (R2 = 0.70). CONCLUSIONS: This experiment suggested that measuring the chemical composition and color score of a corn DDGS sample may provide a quality parameter for identifying corn DDGS sources energy digestibility and metabolizable energy content.