| Brachionus calyciflorus has become an ideal object for the study of aging biology of new invertebrates due to its easy to obtain,short life cycle,convenient for large-scale culture and stable genetic properties.At the same time,a large number of related studies on rotifers as the animals have laid a good ecological and molecular biological basis for this paper.The temperature and diet regulation in the appropriate range have been proved to have a certain regulatory effect on the life extension of the body in the relevant literature,and some popular drugs are also put into use in the research content of the related life extension.Metformin has obvious therapeutic effect on type 2 diabetes and some cancers,and has a allevi ating effect on cardiovascular disease in the early stage.The results show that metformin has anti-aging and anti-inflammatory effects on some human cells by regulating the expression of AMPK.AMPK is a kind of trimer protein composed of three subunits,which is equivalent to the valve controlling energy switch,and acts on the whole process of metabolism regulation of whole body cells and organs of organism,so as to maintain the dynamic balance of energy in cells.The results showed that metformin had the effect of prolonging life on Caenorhabditis elegans,Drosophila melaniogaster,Mus musculus,etc.the mechanism of action was similar to that of simulated diet restriction.This paper has compared the effects of metformin on the life cycle of B.calyciflorus under different temperatures and different dietary restriction,and studies whether metformin has synergistic effect with the combination of the two,and further explored its molecular mechanism,which has provided a theoretical basis for the study of AMPK protein of B.calyciflorus.In this paper,the metformin concentration,which is the most significant effect on the longevity of rotifers at different temperatures,has been studied firstly.Secondly,the changes of metformin on the life cycle characteristics of rotifers under different temperature and dietary restriction have been obtained.Finally,the effects of metformin on AMPK expression in the body of longevity extension have been further studied.The main contents of this paper are divided into the following parts:1.study on the effect of metformin on the longevity of rotifer B.calyciflorus at different temperaturesThe results show that under different temperature treatments,metformin has different effects on the average and maximum life of rotifer,but metformin with concentration of 40 ?M shows the most significant effect on both.At 20?,the average life and longest life of rotifer are 155.4 ± 36.36 h and 240 h respectively,29.72% and 4% longer than that of the control group respectively.The average and longest life span of rotifers were 140.6 ± 32.21 h and 216 h respectively at 8 h and 25?,which were 26.89% and 36 h longer than that of the co ntrol group respectively.At 30?,the average life span and longest life span of rotifer are 109.64 ± 43.1 h and 180 h respectively,22.37% and 12 h longer than that of the control group.The results of different temperature treatments show that 40 ?M metformin has the most significant effect on the longevity of rotifer.2.the effect of temperature and metformin on reproduction and life span of rotifer of calyxThe optimal concentration of metformin in this chapter is 40 ?M,which is the best concentration for rotifers.The results show that metformin had significant effect on the reproductive cycle and life span of rotifer,but the reproduction r ate has no significant change.When the ambient temperature is 20?,the pre reproductive and reproductive stages of rotifers in treatment group are significantly higher than that of the control group,which are 20.25 ± 1.1 h and 76.08 ± 7.4 h,9.46% and 14.1%behind the control group.When the temperature is 25?,the pre reproductive and reproductive stages of rotifers in treatment group are 14.21 ± 0.47 h and 58.5 ±5.9 h,which are 12.54% and 35.5% behind the control group.When the environment temperature is 30?,the pre reproductive and reproductive stages of rotifers in treatment group are 11.88 ± 0.07 h and 19.5 ± 1.74 h,16.33% and 23.42% behind the control group.However,there is no significant difference between the treatment group and the control group in the late reproductive period.From these treatment groups,it can be seen that the energy distribution of rotifers is delayed in sexual maturity(delayed in the early reproductive period)and shortened reproductive period.3.the effect of diet and metformin on reproduction and life span of rotifer of calyxThis study found that the average life span and survival rate of rotifers are increased by appropriate dietary restriction(DR)at the expense of reproduction rate,which is similar to previous studies.The survival rate of rotifer in the control group(without metformin)for 8 hours is higher than that of the control group,with an average life span of 83.67 ± 6.3 h,36.43% longer than that of the normal group.But the number of reproduction is only 5.167 ± 0.57,37.58% less than that of the normal group.Compared with the reproductive cycle,it is found that the early and late reproductive stages of rotifers in the control group increased by 128.9% and 45.96%in the latter group.But the reproductive period is 26.4 ± 4.57 h,which shortens63.53%.The life and reproductive cycle of rotifers in the treatment group(with metformin)fasting for 8 hours are similar to those in the control group.When the fasting is intermittent for 8 hours,there is no significant difference between the treatment group and the control group,but the reproductive cycle of the treatment group changs.Among them,the number of reproduction in the treatment group is 6.9 ± 0.63,increases by 33.54%;the number of reproduction in the early stage is 30 ± 2.36 h,15.6% earlier than that of the control group;the middle stage of reproduction is 31.05 ± 4.66 h,which is 17.61% longer than that of the control group,but there is no significant difference in the later period of appreciation.When fasting for 16 h,the results are similar to the above,that is,the average life and maximum life of the treatment group and the control group are not different,but the treatment group has earlier reproductive stage,longer reproductive period and higher reproductive rate.It is suggested that metformin can protect the reproductive function of rotifers under the restriction of diet.4.the mechanism analysis of metformin on AMPK expression of B.calyciflorus at different temperaturesIn order to reveal the mechanism of metformin on the anti-aging of B.calyciflorus,the effect of metformin on AMPK expression of B.calyciflorus was analyzed in this chapter.The results show that the AMPK expression of the B.calyciflorus shows a tendency of rising first and then decreasing at different temperatures.However,the maximum AMPK expression at 20?,25? and 30? are different at the highest time,which is 12 h,24 h and 36 h,which moves with the increase of temperature.At the same time,comparing the highest AMPK expression at several temperatures,it was found that the AMPK expression at 20? is the highest,which indicats that moderate low temperature could induce AMPK expression. |
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