Effect of lysophosphatidic acid on hepatocellular carcinoma cell migration and its involved mechanisms / 医用生物力学

Objective To investigate the effect of lysophosphatidic acid (LPA) on migration of hepatocellular carcinoma MHCC97H cells and its involved mechanisms. Methods Transwell was utilized to investigate the impact of LPA on cell migration of MHCC97H cells. Furthermore, the role of ROCK in the migration of MHCC97H cells through Y-27632 (a specific inhibitor of ROCK). Then, the expression of F-actin was observed with immunofluorescence staining and Western blotting. Atomic force microscopy (AFM) was employed to investigate elastic modulus of MHCC97H cells. Results LPA significantly promoted the migration of MHCC97H cells, while Y-27632 significantly blocked the migration of MHCC97H induced by LPA. Moreover, LPA up-regulated the expression of F-actin and decreased the elastic modulus of MHCC97H cells. Conclusions LPA promotes MHCC97H cell migration through decreasing the cell stiffness via ROCK/F-actin.

Biomechanics in tissue injury and repair / 医用生物力学

There is an emerging and continuous interest in research about influence of biomechanics on repair and regulation of tissue injury. The development of tissue repair and regenerative medicine provides a new platform for biomechanical research, and biomechanics plays an important role in promoting the development of tissue repair and regenerative medicine. The papers published in special issue of biomechanics and tissue repair in Journal of Medical Biomechanics (Issue No. 5, 2016) were briefly analyzed and reviewed, and the researches in this field were also reviewed and prospected.

Ratio of monocytes to lymphocytes in peripheral blood in patients diagnosed with active tuberculosis

Objective: The ratio of monocytes to lymphocytes in peripheral blood could reflect an indi- vidual's immunity to Mycobacterium tuberculosis. The objective of this study was to evaluate the relationship between ratio of monocytes to lymphocytes and clinical status of patients with active tuberculosis. Methods: This was a retrospective review of data collected from the clinical database of The Fifth People's Hospital of Wuxi, Medical College of Jiangnan University. A total of 419 patients who had newly diagnosed active tuberculosis and 108 cases from 419 patients with tuberculosis therapy either near completion or completed were selected. Controls were 327 healthy donors. Results: Median ratio of monocytes to lymphocytes was 0.36 (IQR, 0.22-0.54) in patients before treatment, and 0.16 (IQR, 0.12-0.20) in controls (p < 0.001). Ratio of monocytes to lymphocytes <9% or >25% was significant predictors for active tuberculosis (OR = 114.73, 95% CI, 39.80-330.71; OR = 89.81, 95% CI, 53.18-151.68, respectively). After treatment, the median ratio of monocytes to lymphocytes recovered to be nearly normal. Compared to other patients, patients with extrapulmonary tuberculosis and of age >60 years were more likely to have extreme ratio of monocytes to lymphocytes (AOR = 2.57, 95% CI, 1.08-6.09; AOR = 4.36, 95% CI, 1.43-13.29, respectively). Conclusions: Ratio of monocytes to lymphocytes <9% or >25% is predictive of active tuberculosis. .

Migration and mechanochemical regulation of bone marrow-derived mesenchymal stem cells / 医用生物力学

Bone marrow-derived mesenchymal stem cells (MSCs) are a kind of multi-functional stem cells with self-renewal and multi-lineage differentiation potentials, which play an important role in repair and regeneration of damaged tissues. The MSCs mobilization from bone marrow and migration through peripheral circulation into injured tissues are a key function of MSCs for tissues repairing. It has been proved in resent years’studies that various mechanical and chemical factors play a significant part in regulating the directed migration of MSCs to the damaged tissue. In this paper, the effects of mechanical and chemical factors on migration of MSCs through peripheral blood circulation to the damaged tissue are reviewed, and the possibly involved molecule mechanisms are discussed, trying to further understand the mechanochemical coupling in this process, and to provide the theoretical guidance for making mechanochemistry induced efficient migration of MSCs in tissue repair in clinic.

Impacts of ground-based microgravity simulation on biological responses of bone marrow mesenchymal stem cells and its underlying mechanisms: A mini-review / 医用生物力学

With the development of space life science, researches on ground-based microgravity simulation become more and more important for spaceflight to complement their limited missions. It is well known that bone marrow mesenchymal stem cells (BMSCs) are pluripotent, self-renewing cells with multi-lineage differentiation capacity on the ground, but their responses under microgravity and the underlying regulatory mechanisms are poorly understood. Ground-based microgravity simulation might affect cell proliferation, apoptosis and expression of surface molecules, and induce cytoskeletal reorganization, as well as alter the differentiation potential of BMSCs. In this review, how ground based microgravity simulation mediates BMSCs’ responses and its involved mechanisms are summarized to further understand the mechano-biological coupling in such process and provide theoretical references for space flight-induced pathophysiological alterations.

Progress of microgravity effects on proliferation and differentiation of bone marrow mesenchymal stem cells / 医用生物力学

Mechanical stimulation plays key roles in regulating the development and function of cells. With the rapid progress of space life science and space biotechnology, the biological behaviors of cells and the involved molecular mechanisms in space have gradually become a hot topic and frontier of the space biology. Bone marrow mesenchymal stem cells (MSCs) plays an important part in clinical cytotherapy and wound healing, due to its self renewal and multi-lineage differentiation potentials. In recent years, researchers have made significant achievements in biological behaviors of cells responding to microgravity environment by means of space simulation technology. In this review, some commonly used microgravity simulation devices were introduced, and changes in MSCs proliferation and differentiation under microgravity and its related molecular mechanisms were briefly summarized, so as to provide theoretical references for prevention and treatment of microgravity related diseases.

Effects from cyclic mechanical stretch on proliferation of rheumatoid arthritis fibroblast-like synoviocytes / 医用生物力学

Objective To investigate the effects from cyclic mechanical stretch on proliferation of rheumatoid arthritis fibroblast-like synoviocytes (RA-FLSs). Methods In the experimental groups, cyclic mechanical stretch, with frequency of 1.0 Hz and magnitude of 3%, 6% and 9%, respectively, was applied to RA-FLSs for 2 h, 6 h, and 12 h. The control group remained in the same culture condition as the experimental groups, but without any mechanical stretch. After mechanical loading, the cell viability was analyzed by MTS, and its proliferation was assayed by flow cytometry. RT-PCR was used to measure the gene expression of the cell cycle regulatory factors, including CDK2, cyclinD1, cyclinE1, and P27. Results Cyclic mechanical stretch with magnitude of 6% and 9% for 6 h or 12 h significantly decreased the cell proliferation and viability in RA-FLSs (P0.05). Conclusions The effects from cyclic mechanical stretch on proliferation of RA-FLSs depend on the stretch magnitude and duration. Mechanical stretch with magnitude of 6% and 9% can inhibit RA-FLSs proliferation, which may be achieved by regulating the expression of Cyclin E1, CDK2 and P27. This study provides references for investigating the role of mechanical stimulation in pathogenesis of rheumatoid arthritis, as well as its prevention and treatment.

Proliferation of bone marrow mesenchymal stem cells induced by cyclic mechanical stretch mediated with ERK signal molecules / 医用生物力学

Objective To investigate effects of the cyclic stretch on rat bone marrow mesenchymal stem cells (rBMSCs) proliferation and the related signal molecules. Methods The cyclic mechanical stretching apparatus was used to study the effects of the cyclic stretch on the growth of rBMSCs with different parameters. The expression of c fos was measured by RT PCR at mRNA level and the levels of phosphorylated extracellular signal regulated kinase 1/2 (p-ERK1/2), total ERK1/2 (t-ERK1/2) and c-fos proteins were detected by Western blotting. Results The proliferation of rBMSCs could be stimulated by the cyclic stretch, and the number of cells was increased to 1.4 times compared with that of the control group at 1 Hz, 10% strain for 15 min and then being static for 6 h. Moreover, the expressions of c-fos mRNA and protein levels were increased significantly after the stimulation of the stretch. On the other hand, it was found that the cyclic stretch could remarkably enhance the phosphorylation of ERK1/2, but did not influence the level of t-ERK1/2. After treated with PD98059, the proliferation of rBMSCs stimulated by the cyclic stretch was inhibited prominently in a dose dependent manner and the expressions of p-ERK1/2, as well as c-fos at gene and protein levels were sharply down regulated. Conclusions ERK1/2 signal molecules play an important role in regulating the cyclic stretch on the proliferation of rBMSCs and transcription factors may take part in the regulations during this progress.