ABSTRACT
The bone turnover capability influences the acquisition and maintenance of osseointegration. The architectures of osteocyte three-dimensional (3D) networks determine the direction and activity of bone turnover through osteocyte intercellular crosstalk, which exchanges prostaglandins through gap junctions in response to mechanical loading. Titanium nanosurfaces with anisotropically patterned dense nanospikes promote the development of osteocyte lacunar-canalicular networks. We investigated the effects of titanium nanosurfaces on intercellular network development and regulatory capabilities of bone turnover in osteocytes under cyclic compressive loading. MLO-Y4 mouse osteocyte-like cell lines embedded in type I collagen 3D gels on titanium nanosurfaces promoted the formation of intercellular networks and gap junctions even under static culture conditions, in contrast to the poor intercellular connectivity in machined titanium surfaces. The osteocyte 3D network on the titanium nanosurfaces further enhanced gap junction formation after additional culturing under cyclic compressive loading simulating masticatory loading, beyond the degree observed on machined titanium surfaces. A prostaglandin synthesis inhibitor cancelled the dual effects of titanium nanosurfaces and cyclic compressive loading on the upregulation of gap junction-related genes in the osteocyte 3D culture. Supernatants from osteocyte monolayer culture on titanium nanosurfaces promoted osteocyte maturation and intercellular connections with gap junctions. With cyclic loading, titanium nanosurfaces induced expression of the regulatory factors of bone turnover in osteocyte 3D cultures, toward higher osteoblast activation than that observed on machined surfaces. Titanium nanosurfaces with anisotropically patterned dense nanospikes promoted intercellular 3D network development and regulatory function toward osteoblast activation in osteocytes activated by cyclic compressive loading, through intercellular crosstalk by prostaglandin.
ABSTRACT
A micro-physiological system is generally fabricated using soft materials, such as polydimethylsiloxane silicone (PDMS), and seeks an inflammatory osteolysis model for osteoimmunological research as one of the development needs. Microenvironmental stiffness regulates various cellular functions via mechanotransduction. Controlling culture substrate stiffness may help spatially coordinate the supply of osteoclastogenesis-inducing factors from immortalized cell lines, such as mouse fibrosarcoma L929 cells, within the system. Herein, we aimed to determine the effects of substrate stiffness on the osteoclastogenesis-inducing potential of L929 cells via cellular mechanotransduction. L929 cells showed increased expression of osteoclastogenesis-inducing factors when cultured on type I collagen-coated PDMS substrates with soft stiffness, approximating that of soft tissue sarcomas, regardless of the addition of lipopolysaccharide to augment proinflammatory reactions. Supernatants of L929 cells cultured on soft PDMS substrates promoted osteoclast differentiation of the mouse osteoclast precursor RAW 264.7 by stimulating the expression of osteoclastogenesis-related gene markers and tartrate-resistant acid phosphatase activity. The soft PDMS substrate inhibited the nuclear translocation of YES-associated proteins in L929 cells without reducing cell attachment. However, the hard PDMS substrate hardly affected the cellular response of the L929 cells. Our results showed that PDMS substrate stiffness tuned the osteoclastogenesis-inducing potential of L929 cells via cellular mechanotransduction.
Subject(s)
Fibrosarcoma , Osteogenesis , Mice , Animals , Mechanotransduction, Cellular , Cell Line , Cell Differentiation , OsteoclastsABSTRACT
BACKGROUND:cAMP response element binding protein (CREB) is a key protein of memory, which is closely related to long-term memory. It wil provide a new way for the treatment of hypoxic ischemic brain damage (HIBD) to study the effects of dental pulp stem cel s transplantation on the long-term behavior and CREB protein via the lateral ventricle in neonatal HIBD rats. OBJECTIVE:To observe the changes in long-term behavior and CREB protein expression in neonatal HIBD rats after human dental pulp stem cel transplantation, thereby providing scientific evidence for clinical treatment of neonatal HIBD. METHODS:Thirty-six healthy 7-day-old Sprague-Dawley rats were randomly divided into normal, HIBD and cel transplantation group. The hypoxic ischemic brain damage models were established in the brain damage and cel transplantation groups. Twenty-four hours after HIBD, human dental pulp stem cel s were injected into the left lateral cerebral ventricle of rats in the cel transplantation group, total y 3×106 living cel s. Equal volume of normal saline was injected into the left lateral cerebral ventricle of rats in the normal control and HIBD groups. RESULTS AND CONCLUSION:The average time to seek water, the average escape latency and escape distance of the human dental pulp stem cel s group were significantly shorter than those of hypoxic ischemic brain injury group (P<0.01), but longer than those in the normal group (P<0.01). Nissl staining showed that the cel s in the hippocampal CA1 region in human dental pulp stem cel s group were more regular, the number of cel s was significantly higher than that of hypoxic ischemic brain injury group, but stil significantly less than that in the normal group (P<0.05). Immunohistochemical staining results showed that the number of CREB positive cel s in human dental pulp stem cel s group was significantly higher than those in HIBD group, but stil significantly less than those in the normal group (P<0.01). It is suggested that human dental pulp stem cel s transplantation could promote the expression of CREB protein in the hippocampal CA1 region, to improve the long-term learning and memory ability of hypoxic ischemic neonatal rats, and thus repair HIBD.
ABSTRACT
Objective To investigate the clinical efficacy of acupoint application plus massotherapy for scapulohumeral periarthritis (periarthritis of shoulder). Method One hundred and two patients with scapulohumeral periarthritis were randomly allocated to treatment and control groups, 51 cases each. The treatment group received acupoint application plus massotherapy and the control group, massotherapy. Both groups were treated for three courses. The VAS score and the Neer shoulder function score were recorded in the two groups before and after treatment. Result The VAS score and the Neer shoulder function score improved in the two groups after treatment compared with before (P<0.05) and improved more in the treatment group than in the control group (P<0.05). Conclusion Clinically acupoint application plus massotherapy has a satisfactory therapeutic effect on scapulohumeral periarthritis with a certain effect on pains in the affected shoulder.
