We are working on the development of functional test methods for cells and tissues by taking advantages of our 3D culture technology and cellular devices. In particular, we provide values that cannot be obtained with conventional testing methods by means of higher-order functional tests that can quantitatively evaluate the functions of target cells and tissues (e.g., nerve transmission, muscle contraction, etc.) in the living cell state. Through these methods, we aim to contribute to a wide range of fields, including basic research, drug discovery, regenerative medicine, and cosmetics. In addition to utilizing these technologies in our own drug discovery research, we are also available for joint research and contracted testing related to these technologies.
Evaluation of skeletal muscle contractility
Culturing cells in a hydrogel-containing medium can control cell migration and orientation and allow cells to form self-assembled pieces of tissue. By culturing skeletal myoblasts in a vessel with two struts under certain culture conditions, millimeter-sized skeletal muscle tissue can be formed in such a way as to cross-link the struts. The resulting skeletal muscle tissue contracts in response to stimuli, making it ideal for quantitative evaluation of skeletal muscle contraction, which will be discussed later.
Contraction of skeletal muscle tissue cultured in 3D (video)
Evaluation of the contractility of skeletal muscle tissue
Skeletal muscle plays an important role in supporting and moving the body through its contraction. However, it is not easy to predict skeletal muscle contractility from gene/protein expression levels and tissue size measurements, as well as to fully reproduce the characteristics of myotubular cells in vivo (differentiation, oriented structure, etc.) in conventional 2D culture.
Skeletal muscle tissue fragments with a three-dimensional structure created by our technology, however, contract in response to electrical stimulation, making it possible to quantitatively evaluate the force of contraction. For example, we showed that our skeletal muscle device using mouse myoblast cells can evaluate the decrease in muscle contractility caused by addition of dexamethasone (DEX) and then recover by addition of IGF-1.
Conceptual diagram of SCAD skeletal muscle contractility evaluation device
(a) Shrinkage displacement after 48 hours of drug addition time
(b) Change in shrinkage displacement over
Example of data acquisition using SCAD skeletal muscle contractility evaluation device (1)
In order to verify the effects of compounds acting on skeletal muscle, an evaluation system using human cells is important. We have also succeeded in constructing a contractility evaluation system using human skeletal muscle cells, and have confirmed that the addition of IGF-1 and reagent A (undisclosed) increases muscle contractility.
Example of data acquisition using SCAD skeletal muscle contractility evaluation device (2)
Cancer cachexia model
What is cancer cachexia?
It is a condition in which the effects of cancer lead to a state of undernutrition and other abnormalities, resulting in a decrease in skeletal muscle mass and body lipids, as well as wasting. Inflammation and hypermetabolism caused by the cancer are suspected to be involved, but the etiology is unknown. Although therapeutic agents have been shown to improve weight and appetite, there are no drugs that are effective in restoring muscle function. Thus, therapeutic agents that can substantially improve muscle strength should be developed.
Cancer cachexia disease model
We are developing a model of cachexia disease for therapeutic drug development utilizing skeletal muscle devices. By adding cancer cell culture supernatant to our 3D skeletal muscle tissue derived from human and mouse myoblasts, we have developed a 3D cachexia disease model, in which the amount of contraction displacement decreases with addition of the cancer supernatant. We can use such amount of contraction displacement as a therapeutic effect indicator in drug discovery research.
(a) Overview of the cachexia disease model
(b) Change in systolic displacement over time
Cachexia disease model using SCAD skeletal muscle contractility evaluation device
Development of a neuromuscular junction model
Skeletal muscles are innervated by motor nerves, and muscle contraction is triggered when receptors on the skeletal muscle receive neurotransmitters released from motor nerve endings. The connection between nerve and muscle is called the neuromuscular junction. Disorders of the neuromuscular junction can cause muscle weakness and atrophy, and in more severe cases such as respiratory muscle disorders can be life-threatening. Myasthenia gravis is a typical neuromuscular junction disorder, but it is also believed to be involved in a variety of other neuromuscular diseases such as muscular dystrophy, amyotrophic lateral sclerosis (ALS), and age-related muscle loss.
Neuromuscular junction
We have been developing a neuromuscular junction model by utilizing our 3D culture technologies of nerve cells and skeletal muscle cells, and also functional testing methods. It is a co-culture device in which axons are extended from motor neurons to make junctions with muscle tissue in a structure that mimics the living body. The device can be used for basic research on the neuromuscular junction and for evaluation and exploration of compounds that affect the motor neuron and/or neuromuscular junction.
SCAD neuromuscular junction device