ABSTRACT
Idiopathic pulmonary fibrosis (IPF) is a progressive scar-forming disease with a high mortality rate that has received widespread attention. Epithelial mesenchymal transition (EMT) is an important part of the pulmonary fibrosis process, and changes in the biomechanical properties of lung tissue have an important impact on it. In this paper, we summarize the changes in the biomechanical microenvironment of lung tissue in IPF-EMT in recent years, and provide a systematic review on the effects of alterations in the mechanical microenvironment in pulmonary fibrosis on the process of EMT, the effects of mechanical factors on the behavior of alveolar epithelial cells in EMT and the biomechanical signaling in EMT, in order to provide new references for the research on the prevention and treatment of IPF.
Subject(s)
Humans , Epithelial-Mesenchymal Transition , Idiopathic Pulmonary Fibrosis , Signal TransductionABSTRACT
Objective To investigate the difference of matrix stiffness in different regions of tibial plateau in osteoarthritis (OA) and its effects on morphology of the cartilage and mitochondria. Methods The tibial plateau cartilage specimens of OA were obtained for nanoindentation test, transmission electron microscopy and histological analysis. The stiffness of cartilage matrix in different regions of OA tibial plateau was detected by nano-indentation. The morphology of cartilage mitochondria in different regions was observed by transmission electron microscopy, and the changes of mitochondrial plane area, shape and ridge volume density were quantitatively analyzed. Cartilage injury in different regions of OA tibial plateau was observed by histological staining. Results The cartilage of OA tibial plateau showed regional heterogeneity, and the cartilage and mitochondria on medial side of varus knee OA were more severe, and the matrix stiffness was higher. The OA scores were positively correlated with matrix stiffness. There was also a significant correlation between OA scores and mitochondrial morphology: the higher OA scores, the larger and rounder mitochondrial plane area, and the lower cristae volume density. Conclusions The differences of tibial plateau revealed the correlation between cartilage matrix stiffness, OA scores and mitochondrial morphological parameters. The increased cartilage matrix stiffness may be the main cause of chondrocyte mitochondrial injury, and further aggravate the progression of OA.
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The mechanical microenvironment of cells plays a critical role in regulating the physiological function of cells. Cells in vivo are often subjected to a variety of mechanical forces from their mechanical micro-environment, such as shear, tension, and compression. At the same time, cells can adhere to the extracellular matrix (ECM) through adhesion molecules (such as integrin-ligand binding), and further sense the stiffness of the ECM. Cell mechanics mainly studies the properties and behavior of living cells under mechanical forces, and how they relate to cell functions. This review summarized the advances in cell mechanics in 2022, focusing on integrin-ligand interactions and the effects of matrix stiffness and mechanical forces on cell physiological behavior and morphogenesis.
ABSTRACT
Idiopathic pulmonary fibrosis (IPF) is a common chronic interstitial fibrotic disease. During the fibrosis process, myofibroblasts are abnormally activated, collagen is deposited in large quantities and the biomechanical characteristics of lung tissue are significantly altered. In this paper, a systematic review about the changes in lung tissues, cellular biomechanical properties and biomechanical signals during the process of IPF was presented, and the in vitro reproduction of biomechanical features and therapeutic strategies for targeting biomechanics wassummarized, so as to provide references for clinical prevention and treatment of IPF.
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Objective After hydrogen bonding between collagen ( COL) and silk fibroin ( SF ) at different concentrations, a composite scaffold with adjustable stiffness was prepared by combining with gel system, and its physical and chemical properties were characterized. Methods SF with different qualities was dissolved in sodium alginate (SA) solution, then COL solution at different concentration and calcium carbonate ( CaCO3 ) powder were added. The hydrogels of SC1, SC2, and SC3 groups were obtained by taking out the mixed solution and adding some gluconic acid lactone ( GDL) powder, and different SF scaffolds were obtained after freeze drying. Results The SF scaffolds with adjustable stiffness were successfully prepared. The compression moduli of SC1, SC2, and SC3 groups were (17. 31±2. 73), (24. 12±1. 81), (32. 54±1. 81) kPa, respectively. The innerstructure of the scaffolds was observed. From SC1 group to SC3 group, pores of the scaffolds were smaller and fewer, and hydrophilicity of the materials become better and better. Conclusions Three-dimensional ( 3D) porous scaffolds with different matrix stiffness can be prepared by changing the concentration of SF and COL solution. The concentration of SF and COL is proportional to the compression modulus, water absorption, water retention and swelling rate of SF scaffolds, while inversely proportional to porosity. The findings of this study are expected to provide theoretical guidance for construction of scaffolds with appropriate matrix stiffness for inducing osteogenic differentiation of mesenchymal stem cells
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Extracellular matrix (ECM) has been implicated in tumor progress and chemosensitivity. Ovarian cancer brings a great threat to the health of women with a significant feature of high mortality and poor prognosis. However, the potential significance of matrix stiffness in the pattern of long non-coding RNAs (lncRNAs) expression and ovarian cancer drug sensitivity is still largely unkown. Here, based on RNA-seq data of ovarian cancer cell cultured on substrates with different stiffness, we found that a great amount of lncRNAs were upregulated in stiff group, whereas SNHG8 was significantly downregulated, which was further verified in ovarian cancer cells cultured on polydimethylsiloxane (PDMS) hydrogel. Knockdown of SNHG8 led to an impaired efficiency of homologous repair, and decreased cellular sensitivity to both etoposide and cisplatin. Meanwhile, the results of the GEPIA analysis indicated that the expression of SNHG8 was significantly decreased in ovarian cancer tissues, which was negatively correlated with the overall survival of patients with ovarian cancer. In conclusion, matrix stiffening related lncRNA SNHG8 is closely related to chemosensitivity and prognosis of ovarian cancer, which might be a novel molecular marker for chemotherapy drug instruction and prognosis prediction.
Subject(s)
Female , Humans , Cisplatin/pharmacology , Elasticity/physiology , Etoposide , Extracellular Matrix/physiology , Ovarian Neoplasms/metabolism , RNA, Long Noncoding/metabolismABSTRACT
@#Currently, cell transplantation in combination with scaffold materials are one of the main strategies in periodontal bone tissue engineering. In periodontal bone tissues, the stiffness and spatial structure of tissues such as alveolar bone and cementum differ, and the difference in mechanical properties of scaffolds also has disparate effects on the proliferation and differentiation of stem cells. Accumulating evidence shows that mechanical stimulating factors such as matrix stiffness and scaffold topography modulate biological behaviors of various seeding cells, including adipose-derived stem cells and periodontal ligament stem cells. A hard matrix can promote cytoskeletal stretching of stem cells, leading to nuclear translocation of Yes-associated protein (YAP) and promoting osteogenic differentiation by upregulating alkaline phosphatase (ALP) and osteocalcin (OCN) via the Wnt/β-catenin pathway. The topologic structure of scaffolds can affect cell adhesion and cytoskeletal remodeling, increase the hardness of cells and promote the osteogenic differentiation of stem cells. In this paper, the effects of mechanical stimulation on the differentiation of stem cells in periodontal bone tissue engineering are reviewed.
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Objective To investigate the detailed molecular mechanism of matrix stiffness regulating cell drug resistance. Methods Polyacrylamide hydrogels of soft substrate (10 kPa), hard substrate (38 kPa) and rigid substrate (57 kPa) with different matrix stiffness were configured to simulate the physical matrix stiffness at different stages of breast cancer in vivo. Results The cell proliferation rate of the hard substrate was significantly higher than that of the soft and rigid substrates. The intracellular endocytosis was significantly lower on the hard substrate. The YAP nucleus translocation increased significantly on the hard substrate, compared with the soft and the rigid substrates, indicating that YAP was a key molecule involved in drug resistance of tumor cells. Conclusions Matrix stiffness could regulate the drug resistance of breast cancer cells through YAP activation. This study not only provides a new direction for elucidating the mechanism of drug resistance, but also lays a new foundation for the drug delivery system of breast cancer treatment.
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As the common pathway of chronic renal diseases leading to end-stage renal failure, renal tubulointerstitial fibrosis is characterized by the deposition of extracellular matrix and scar hardening. Our study aimed to construct an in vitro cell culture platform to explore the impact of matrix stiffness on cell morphology and function of renal tubular epithelial cells. Photopolymerized polyacrylamide gels (PAA gel) with varying stiffnesses as model substrates was selected to simulate the matrix stiffness of normal and fibrotic renal tissues with elastic moduli ranging from 1 to 40 kPa. The human renal tubular epithelial cells (HK-2) were seeded on the surface of PAA gels. The impact of matrix stiffness on the morphology of HK-2 were investigated via immunofluorescence staining and confocal microscopy. The expression levels of glucose transporter 1 (GLUT1), glucose transporter 2 (GLUT2), glucose transporter 5 (GLUT5) were semi-quantitatively analyzed. With increasing matrix stiffness, both the levels of GLUT1 and GLUT5 in HK-2 cells were significantly decreased, whereas the expression level and the distribution pattern of GLUT2 in HK-2 remained unchanged with stiffness variation.
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Fluorescent polystyrene nanospheres (PS) were used to explore the impact of substrate stiffness on cell uptake of nanoparticles in the breast cancer cells. Polyacrylamide (PAA) gels with varying stiffness were prepared by photopolymerization, and type I rat tail collagen was covalently conjugated on the surface of PAA gels to facilitate cell adhesion. Type I rat tail collagen was also used to fabricate collagen gels for 3D cell culture. Cells of human breast cancer cell line MCF-7 were incubated in the 2D culture on PAA gels and 3D culture within collagen gels. Next, nanospheres of 20 nm and 50 nm polystyrene were applied to MCF-7 cells in the 2D or 3D cultures. Cell morphology and uptake efficiency were observed with confocal microscopy. Our study demonstrates that substrate stiffness differentially regulated the cell morphology as well as the cell uptake behavior of polystyrene nanospheres in MCF-7 cells under 2D or 3D culture conditions.