Establishment Of Mature And Functional Muscle Evaluation System Based On Micro-pattern And Micro-tissue Cultivation

The athletic ability of animals is realized in the muscular system.In vertebrates,there are primarily three types of muscular systems: skeletal muscle,cardiac muscle,and smooth muscle.Muscular tissue is a highly organized contractile apparatus,and the orderly arrangement of muscular tissue is a necessary condition for generating contractile function.For example,in skeletal muscle,a large number of orderly arranged muscle fibers form muscle bundles,and a large number of muscle bundles are aligned in the same direction,forming macroscopic skeletal muscle tissue.In the heart,cardiac muscle is composed of syncytia,and individual cells are interconnected through intercalated discs to form branching structures,which together form a unified mechanical and electrophysiological system.Smooth muscle exists within the hollow organs and also exhibits a highly oriented arrangement.For instance,in blood vessels,smooth muscle is spindle-shaped and distributed at a certain spiral angle.Similarly,the orderly arrangement of myosin filaments,actin filaments,mitochondria,and other cellular structures within muscle cells is the foundation for generating contractile force in muscle cells.When studying muscle tissue in vitro,aligning muscle cells at the same angle is necessary to produce synchronous and aligned contractions.The orderly arrangement of muscular tissue can generate synchronized and same-direction contraction,allowing for coordinated interaction of the contractile force and distance of individual cells,thus reflecting macroscopic tissue movement at the level of organs and tissues.Currently,there are various methods available to achieve the alignment of muscle cells.In cell culture,micropatterned surfaces can be used to control the direction of cell growth.When culturing muscle cells,striated surfaces are commonly used to achieve oriented cell growth.In tissue culture,muscle cells are also elongated and oriented due to the tension within the tissue.In this experiment,two patients with inherited cardiovascular diseases were found to have pathogenic mutations in the DSP and FBN1 genes through exon sequencing.These mutations resulted in abnormalities in cardiac and smooth muscle cells respectively.We obtained patientspecific stem cell lines with the corresponding genotype through somatic cell reprogramming,we obtained patient-specific stem cell lines with the corresponding genotype.By inducing the differentiation of i PSCs in vitro,we obtained smooth muscle cells and cardiac muscle cells,respectively.In our constructed 2D and 3D tissue culture systems,we detected structural and functional differences between mutant and wild-type cardiac and smooth muscle cells.