How Does a Cell Change Flow Direction Due to a Micro Groove?

The change in direction of a cell flowing over an oblique micro groove has been analyzed in vitro. The micro flow-channel (0.05 mm height x 1 mm width x 25 mm length) with oblique micro grooves (4.5 μm depth) was manufactured on a polydimethylsiloxane (PDMS) disk by the micromachining technique. The angle between the main flow direction and the longitudinal axis of the groove is 45 degrees. The effect of variation of the groove width (0.03 mm, 0.04 mm, and 0.05 mm) was studied. Myoblasts (C2C12: mouse myoblast cell line) were used in the test. The main flow velocity (0.02 mm/s < vx < 0.23 mm/s) of the medium was controlled by the pressure difference between the inlet and the outlet. The shape of each flowing cell was tracked on a movie recorded by the camera attached to the eyepiece of the microscope. The experimental results show that the change of the direction of each cell by each groove depends on the shape of the cell, which depends on both the shape of the cell and the width of the groove.

Biocompatibility Computation of Muscle Cells on Polyhedral Oligomeric Silsesquioxane-Grafted Polyurethane Nanomatrix

This study was performed to appraise the biocompatibility of polyhedral oligomeric silsesquioxane (POSS)-grafted polyurethane (PU) nanocomposites as potential materials for muscle tissue renewal. POSS nanoparticles demonstrate effectual nucleation and cause noteworthy enhancement in mechanical and thermal steadiness as well as biocompatibility of resultant composites. Electrospun, well-aligned, POSS-grafted PU nanofibers were prepared. Physicochemical investigation was conducted using several experimental techniques, including scanning electron microscopy, energy dispersive X-ray spectroscopy, electron probe microanalysis, Fourier transform infrared spectroscopy, and X-ray diffraction pattern. Adding POSS molecules to PU did not influence the processability and morphology of the nanocomposite; however, we observed an obvious mean reduction in fiber diameter, which amplified specific areas of the POSS-grafted PU. Prospective biomedical uses of nanocomposite were also appraised for myoblast cell differentiation in vitro. Little is known about C2C12 cellular responses to PU, and there is no information regarding their interaction with POSS-grafted PU. The antimicrobial potential, anchorage, proliferation, communication, and differentiation of C2C12 on PU and POSS-grafted PU were investigated in this study. In conclusion, preliminary nanocomposites depicted superior cell adhesion due to the elevated free energy of POSS molecules and anti-inflammatory potential. These nanofibers were non-hazardous, and, as such, biomimetic scaffolds show high potential for cellular studies and muscle regeneration.

20-Hydroxyecdysone activates the protective arm of the RAAS via Mas receptor

20-Hydroxyecdysone (20E) is a steroid hormone that plays a key role in insect development through nuclear ecdysteroid receptors (EcR/RXR complex) and at least one membrane GPCR receptor (DopEcR). It also displays numerous pharmacological effects in mammals, where its mechanism of action is still debated, involving either an unidentified GPCR or the estrogen ERβ receptor. The goal of this study was to better understand 20E mechanism of action in mammals. A mouse myoblast cell line (C2C12) and the gene expression of myostatin (a negative regulator of muscle growth) was used as a reporter system of anabolic activity. Experiments using protein-bound 20E established the involvement of a membrane receptor. 20E-like effects were also observed with angiotensin-(1-7), the endogenous ligand of Mas. Additionally, the effect on myostatin gene expression was abolished by Mas receptor knock-down using small interfering RNA (siRNA) or pharmacological inhibitors. 17β-Estradiol (E2) also inhibited myostatin gene expression, but protein-bound E2 was inactive, and E2 activity was not abolished by angiotensin-(1-7) antagonists. A mechanism involving cooperation between the Mas receptor and a membrane-bound palmitoylated estrogen receptor is proposed. The possibility to activate the Mas receptor with a safe steroid molecule is consistent with the pleiotropic pharmacological effects of ecdysteroids in mammals and, indeed, the proposed mechanism may explain the close similarity between angiotensin-(1-7)’s and 20E’s effects. Our findings open up many possible therapeutic developments involving stimulation of the protective arm of the renin-angiotensin-aldosterone system (RAAS) with 20E.

Anti-diabetic Activity of Buchanania lanceolata Wight Extracts in Streptozocin persuade Diabetic Animal Model

Diabetes mellitus is a well-established metabolic syndrome that originates from a complete or virtual requirement of insulin and low insulin action, which leads to hyperglycemia and malformation in the regulation of lipids, proteins, and carbohydrates. Micro and macrovascular difficulties are mainly developed in diabetic patients when compared with normal individuals. The plant variety selected for this study was Buchanania lanceolata Wight (B. lanceolata), which comes under the family of Anacardiaceae, which was originated in India and Myanmar. In the current research, an aqueous extract of B. lanceolata was isolated from the plant barks. Glucose uptake was carried out by using L6 myoblast cell lines, and the results showed an improved glucose uptake in vitro by the aqueous extract of bark of B. lanceolata. Moreover, it was also studied for acute dose oral toxicity and anti-diabetic studies in Wistar albino rats. The aqueous extract did not demonstrate any toxic conditions or mortality at single dose feeding of 2000 mg/kg/p.o and was examined for 15 days. It was also found out the variations in glucose level, hematology parameters, lipid level, and biochemical factors of both control and treated animals. Currently, the natural drug gained attention among researchers because of the problems developed by the allopathic remedial representative. The examination of anti-diabetic agents of an herbal source that are used in folk medicine is thus of huge significance. Management of diabetes with artificial medicines is an expensive and high probability for side effects. As a result, it is necessary to develop plant-based medicines for diabetes. B. lanceolata is a promising herbal drug for diabetic treatment not only in Ayurveda but also in other folk medicine.

Hysteresis Effect of Tangential Force Field With Centrifuge on Myoblast: Cultured on Striped Pattern of Micro Ridge for Direction Control

Hysteresis effects of the direction of mechanical stimulation on the cell behavior have been examined in vitro. A micro ridge pattern was made on the surface of the scaffold to align the directions of the cells being stimulated. The stripe pattern (0.7 μm heigh, 3 μm wide, and 3 μm interval) was created by the photolithography technique. Three regions, which have the uniform value of the angle between the longitudinal direction of the ridge and the direction of the tangential force, were set: 0, 45, and 90 degrees in each region. Myoblasts (C2C12: mouse myoblast cell line) were used in the experiment. The scaffold plate with cells was set in the tube of a conventional centrifuge placed in an incubator to apply the tangential force field to each cell. After the cell culture for 5 hours with centrifugation, the behavior of each cell was analyzed on time-lapse microscopic images for 10 hours. Experimental results show that cell activities (migration and deformation) are enhanced after stimulation of tangential forces perpendicular to the long axis of myoblasts.

Movement of Myoblast Flowing Through Electric Field Perpendicular to Flow Channel

The sorting technology with little invasion to cells would be applied to regenerative medicine and diagnosis. In this study, dielectrophoresis is focused on. The dielectrophoretic effect on the flowing myoblasts was maximized by adjusting several parameters: the shape of the electrodes, the amplitude and frequency of the alternating current. The suspension of C2C12 (mouse myoblast cell line) was injected into the channel, and the movement of each flowing cell was analyzed at the microscopic movie image. A pair of titanium-coated (200 nm thick) asymmetric surface electrodes (a triangular electrode with a tip angle of 0.35 rad and a rectangular reference electrode with a flat edge) was manufactured by photolithography technique. With the alternating square cyclic wave at the frequency of 3 MHz and the amplitude of current of ± 7.5 mA, 70 μm movement along the electric field (perpendicular to the main flow direction) of the cell was obtained. The movement along the electric field is governed by several parameters of the cell: the diameter, the deformation ratio, and the direction of the major axis. The method can be applied to cell sorting.

Behavior of Cell Passing Through Micro Slit Between Micro Machined Plates

Deformation of each cell, as it passes through the micro-slit in the flow channel, has been investigated in vitro. A slit with a rectangular cross section (height 10 μm, width 0.4 mm, length 0.1 mm) was made in the center of the flow path by photolithography technique. Myoblasts (C2C12: mouse myoblast cell line) were used for the test. The flow rate of the medium, in which the cells were suspended, was controlled by a pressure head between the inlet and the outlet. Deformation of each cell passing through the micro-slit was observed with an inverted phase contrast microscope. Using the contour of the image of each cell passing through the slit intermittently, several parameters were analyzed: the two-dimensional projected area, the degree of deformation by ellipse approximation, and the deformation direction. The experimental results show that elongation of the cell in the slit tends to decrease the area of the cell.

Hormonally regulated myogenic miR-486 influences sex-specific differences in cancer-induced skeletal muscle defects

Cancer-induced skeletal muscle defects show sex-specific differences in severity with men performing poorly compared to women. Hormones and sex chromosomal differences are suggested to mediate these differences, but the functional skeletal muscle markers to document these differences are unknown. We show that the myogenic microRNA miR-486 is a marker of sex-specific differences in cancer-induced skeletal muscle defects. Cancer-induced loss of circulating miR-486 was more severe in men with bladder, lung and pancreatic cancers compared to women with the same cancer types. In syngeneic model of pancreatic cancer, circulating and skeletal muscle loss of miR-486 was more severe in male mice compared to female mice. Estradiol (E2) and the clinically used selective estrogen receptor modulator toremifene increased miR-486 in undifferentiated and differentiated myoblast cell line C2C12 and E2-inducible expression correlated with direct binding of estrogen receptor alpha (ERα) to the regulatory region of miR-486 gene. E2 and toremifene reduced the actions of cytokines such as myostatin, TGFβ and TNFα, which mediate cancer-induced skeletal muscle wasting. E2 and toremifene treated C2C12 myoblast/myotube cells contained elevated levels of active AKT with corresponding decrease in the levels of its negative regulator PTEN, which is a target of miR-486. We propose an ERα:E2-miR-486-AKT signaling axis, which reduces the deleterious effects of cancer-induced cytokines/chemokines on skeletal muscle mass and/or function.