The road to drug discovery for heart‐related diseases is challenged by advancement in whole‐heart and reliable animal heart models. In vitro model is a solution to replacing the unpredictable in vivo heart models. However, the techniques are time‐ and cost‐consuming. Cardiomyocyte cell line that expands in culture can be trained by mechanical stimulation to express cardiac biomarkers. The use of mechanical stimulation such as cyclic stretching can be more predictable, reliable in terms of cardiac marker expressions. The heart is an organ that is in constant dynamic which requires regulation for reactive oxygen species (ROS) to prevent pathological process. Here, we used cyclic stretching to stimulate cardiomyocytes with mild (5%), and aggressive (25%) strains at 1Hz. The stimulated cardiomyocytes expressed the cardiac characteristic markers Atrial natriuretic factor (ANF), and β‐myosin heavy chain (β‐MHC) after 24h of stretching. The 3H‐1,2‐dithiole‐3‐thione (D3T) has been reported to be a potent inducer of antioxidant genes through activation of the transcription factor Nrf2, and Nrf2 has been reported to play a role in cardiac remodeling.In this study, we investigated the effect of the D3T on the cardiomyocytes stimulated at mild, or aggressive strain. Results show that the aggressive strain reduced the β‐MHC expression, and the D3T enhanced the β‐MHC expression in cardiomyocytes that were stimulated with aggressive strain.Support or Funding InformationThis research is supported by VGHKS107‐076, VGHKS107‐168, VGHKS107‐175, MOST104‐2320‐B‐0751B‐003‐MY3, and MOST106‐2320‐B‐075B‐001.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

BackgroundPhysical forces are important for maintaining cellular functions. Recently, mechanotherapy, a field that deals with mechanical stimulation connections with Biological functions at cellular and molecular levels has become the emerging hot topic in clinical medicine. Many mammalian cell types contain mechanosensor protein, from cells such as ear, nasal, skin epithelium, colon, muscle, kidney, to lung cells. The forces experienced by living cells such as cyclic (heartbeat), sustained (skin), cyclic and sustained stretching (rectal muscle) can be simulated by in vitro approach. Since evidence on mechanical stimulation-induced Biological functions is still lacking, we will study the various forces based on their physiological functions and meanings. We hypothesize that stretching of cells by in vitro approach can regulate cell functions that have physiological meaning. Methods A company based in Taiwan has developed a device with four modules for stretching. First, we will examine the stretching modules using 1) normal (skin epithelial cells) and 2) pathological cells (lung, skin, colon, or oral cancer cells) to stretch cells to study the cytoskeletal structure actin expression using immunofluorescence assay, and collagen secretion by Sirius Red staining. Second, we will develop 3D culture system using gelatin scaffold in which we will focus on cell adhesion (Ecadherin expression), proliferation (BrdU: 5-bromo-2'-deoxyuridine incorporation), and the secreted extracellular matrix (Collagen staining). ResultsWe tested lung cancer cells (A549), skin epithelial cancer cells (A431), colon cancer cells (WiDr), and oral cancer cells (SCC-25) for adhesion to the membrane coated with 1) non-coated, 2) collagen-coated, 3) Nitrogen Hydroxide (NH2)coated surfaces that are stretchable. The A549 and A431 cells were subjected to cyclic stretching (5%, 1Hz, 6h). Results showed that actin filaments were organized in different pattern compared to that of No stretch. The study on the correlation between stretching and cellular function at molecular level is ongoing. ConclusionsThe effect of cyclic stretching on the various cell types show differences in actin distribution which may pose specific Biological function. As a result, we will continue to establish the criteria for mimicking the in vivo using the mechanical stimulation device.

BackgroundAcute myocardial infarction (AMI) often leads to a variety of cardiomyopathies in human. To elucidate the pathological mechanisms and to ameliorate cardiac damage is a crucial issue for treating AMI. Our previous research disclosed that administration of paricalcitol, an active vitamin D (VD3) agonist, attenuated cardiac fibrosis induced by isoproterenol injections in a cardiomyopathic rat model. The effect was possibly involved with regulation of endothelial to mesenchymal cell transition (EndoMT). We further hypothesize that VD3 can modulate EndoMT, certain growth factors, and cell fibrosis via vitamin D receptor (VDR) dependent pathway in endothelial cell lines. Methods A novel simulation system (ATMS Boxer TM Dynamic Stretch Culture System) was utilized to mimic a physiological condition of dynamic heart-beating and stretching (for example, subjected to 15%, 1 Hz stretching for 6, 24 hours) and to culture cardiac microvascular endothelial cells (HMVEC) for investigation of the effects of VD3-VDR pathway on EndoMT and cell fibrosis induced by transforming growth factor-β1 (TGF-β1). ZK159222, a VDR antagonist, will be also utilized to study the effect of VD3-VDR pathway. Results HMVECs were treated with 5 ng/ml TGF-β1 for 2, 5 days for induction of EndoMT expression and cell fibrosis. The results showed that upstream signals of cell fibrosis as SNAIL, SLUG, α-SMA (a cell marker of a mesenchymal cell), and collagen content were up-regulated, accompanied with decreased CD31 (a cell marker of an endothelial cell) on Western blot analyses. These findings were compatible with expression of TGF-β1 evoked EndoMT and cell fibrosis using the in vitro simulation model. Investigation of the effect of VD3-VDR pathway on EndoMT and cell fibrosis is ongoing. Conclusions EndoMT expression and cell fibrosis can be evoked by TGF-β1 through the in vitro simulation model. We will continue to investigate the effects and mechanisms of VD3-VDR pathway on EndoMT and cell fibrosis using the model and ZK159222.

Thought runs through the mind like blood runs through our body to keep us alive. Like the mind, the body does not stay inert and is in constant motion. Not a single cell in our body is left inert unless cell is under stress or dying. These scenarios are reflected upon when a person is sick, the person lies in bed with less movement; however, is active when the person is healthy. The topic of mechanical stimulation has emerged due to the increasing understanding of the physical stimulations we face each day. Further understanding of the mechanically-regulated mechanism can help us explore the pathological events in a disease. Here, we reviewed the role of sensory proteins in pathological events that are observed in cardiomyopathy, cancer, respiratory, renal, obesity, genetics, physical injury and bacterial infection. Taken together, sensory proteins are mechanically-activated which assist reception of external physical stimulation and convert into biochemical to trigger intracellular signaling cascade.