Pei Qi-ming, Zhan Xuan, Yang Li-jian, Bao Chun, Cao Wei, Li An-bang, Rozi Anvar, Jia Ya
Department of Physics and Institute of Biophysics, Central China Normal University, Wuhan 430079, China and School of Physical Science and Technology, Yangtze University, Jingzhou 434023, China.
Department of Physics and Institute of Biophysics, Central China Normal University, Wuhan 430079, China.
Phys Rev E Stat Nonlin Soft Matter Phys. 2014 Mar;89(3):032715. doi: 10.1103/PhysRevE.89.032715. Epub 2014 Mar 25.
The number of stem cells in a colonic crypt is often very small, which leads to large intrinsic fluctuations in the cell population. Based on the model of cell population dynamics with linear feedback in a colonic crypt, we present a stochastic dynamics of the cell population [including stem cells (SCs), transit amplifying cells (TACs), and fully differentiated cells (FDCs)]. The Fano factor, covariance, and susceptibility formulas of the cell population around the steady state are derived by using the Langevin theory. In the range of physiologically reasonable parameter values, it is found that the stationary populations of TACs and FDCs exhibit an approximately threshold behavior as a function of the net growth rate of TACs, and the reproductions of TACs and FDCs can be classified into three regimens: controlled, crossover, and uncontrolled. With the increasing of the net growth rate of TACs, there is a maximum of the relative intrinsic fluctuations (i.e., the Fano factors) of TACs and FDCs in the crossover region. For a fixed differentiation rate and the net growth rate of SCs, the covariance of fluctuations between SCs and TACs has a maximum in the crossover region. However, the susceptibilities of both TACs and FDCs to the net growth rate of TACs have a minimum in the crossover region.
结肠隐窝中的干细胞数量通常非常少，这导致细胞群体存在较大的内在波动。基于结肠隐窝中具有线性反馈的细胞群体动力学模型，我们提出了一种细胞群体（包括干细胞、过渡增殖细胞和完全分化细胞）的随机动力学。利用朗之万理论推导了稳态附近细胞群体的法诺因子、协方差和磁化率公式。发现在生理合理的参数值范围内，过渡增殖细胞和完全分化细胞的稳定群体表现出作为过渡增殖细胞净增长率函数的近似阈值行为，并且过渡增殖细胞和完全分化细胞的增殖可分为三种模式：受控、交叉和不受控。随着过渡增殖细胞净增长率的增加，在交叉区域过渡增殖细胞和完全分化细胞的相对内在波动（即法诺因子）存在最大值。对于固定的分化率和干细胞的净增长率，干细胞和过渡增殖细胞之间波动的协方差在交叉区域有最大值。然而，过渡增殖细胞和完全分化细胞对过渡增殖细胞净增长率的磁化率在交叉区域有最小值。
