Effect of heterochronic parabiosis model on old mouse spine muscle aging

English Keywords:Parabiosis  Spine degeneration  Young blood  Aging

English Abstract:

  【Abstract】 Objectives: Heterochronic parabiosis model was used to achieve the chimerism of young and elderly individuals through blood circulation, so as to reverse paravertebral muscle aging. Methods: With the means of surgical pairing on wild type C57B6 female mouse, young(Y, age 4 mth) and old(O, age 18 mth) by using the heterochronic parabiosis and isochronic prarbiosis model. Mouse were sacrificed eight weeks after surgical pairing. After separating four main groups, young isochronic(YI), young heterochronic(YH), old isochronic(OI) and old heterochronic(OH) were obtained. After the treatment, matrix gene expression, total glycosaminoglycans, Western blot and immunofluorescence analysis were used to determine the effects of heterochronic parabiosis model. Results: GAG assay showed that the YI, YH, OH, OI data presented a decreasing trend in each group, YI 2.91±0.17, YH 2.01±0.21, OH 2.23±0.36, OI 1.18±0.09, respectively. There was significant difference between the two groups(P＜0.05). The immunofluorescence demonstrated increased Aggrecan protein, YI 717.25±64.44, YH 611.59±28.45, OH 683.04±17.95, OI 570.34±31.81, respectively. There was a statistical difference between the OH and OI group(P<0.05). And the LI8 expression showed YI 494.20±28.35, YH 561.62±44.72, OH 602.35±45.57, OI 726.36±58.40; the P16 expression showed YI 701.30±27.21, YH 695.92±31.06, OH 754.82±25.78, OI 815.54±24.70, with no statistical significance among the groups. The expression of autophagy gene LC3 Ⅱ/Ⅰ showed a decreasing trend by using Western blot, which was YI 0.39±0.09, YH 0.29±0.05, OH 0.26±0.04, OI 0.16±0.01; the senescence gene P21 protein expression was YI 1.09±0.23, YH 1.32±0.12, OH 1.54±0.03, OI 1.86±0.06. The expression of MMP13 protein was YI 0.59±0.11, YH 0.68±0.13, OH 0.88±0.15, OI 1.11±0.18. Among the LC3 Ⅱ/Ⅰ, P21 and MMP13 expressions, there was no significant difference between YI and YH group(P>0.05), but significant difference in OH compared with OI group(P<0.05). Conclusions: Our findings provide evidence supporting the hypothesis that systemic blood circulation can affect paravertebral muscle degeneration. The heterochronic parabiosis model through the young blood circulation can variably promote tissue proliferation, reduce tissue damage, and restore organ function.