PubMed | Hiroshima University, Cellectricon AB and Lund University
Type: Journal Article | Journal: The European journal of neuroscience | Year: 2016
Knowledge about nerve regeneration after nerve injury and reconstruction in appropriate diabetic animal models is incomplete. Short-term nerve regeneration after reconstruction of a 10-mm sciatic nerve defect with either a hollow chitosan conduit or an autologous nerve graft was investigated in healthy Wistar and diabetic Goto-Kakizaki (GK) rats. After 21 days, axonal outgrowth, the presence of activated and apoptotic Schwann cells and the thickness of the formed matrix in the conduits were measured. In general, nerve regeneration was superior in autologous nerve grafts. In chitosan conduits, a matrix, which was thicker in diabetic rats, was formed and was positively correlated with length of axonal outgrowth. Axonal outgrowth in conduits and in nerve grafts extended further in diabetic rats than in healthy rats. There was a higher percentage of activating transcription factor 3 (ATF3)-immunostained cells in nerve segments from healthy rats than in diabetic rats after autologous nerve graft reconstruction. In chitosan conduits, more cleaved caspase 3-stained Schwann cells were generally observed in the matrix from the diabetic rats than in healthy rats. However, there were fewer apoptotic cells in the distal segment in diabetic rats reconstructed with a chitosan conduit. Preoperative glucose levels were positively correlated with axonal outgrowth after both reconstruction methods. Axonal regeneration was better in autologous nerve grafts than in hollow chitosan conduits and was enhanced in diabetic GK rats compared to healthy rats after reconstruction. This study provides insights into the nerve regeneration process in a clinically relevant diabetic animal model.
Lindwall Blom C.,Cellectricon AB |
Martensson L.B.,Lund University |
Dahlin L.B.,Skåne University Hospital
BioMed Research International | Year: 2014
We investigated (a) if activation of the mitogen activated protein kinase (MAPK) pathway was linked to the stress activated protein kinase (SAPK) pathway and (b) if JNK was required for activation of c-Jun in Schwann cells of rat sciatic nerve following injury. To this aim, ERK1/2 and the transcription factors c-Jun and ATF-3 were studied by immunohistochemistry in segments of transected nerves. We utilized pharmacological inhibitors of both signal transduction pathways in vitro to determine the effects on downstream signalling events, such as c-Jun activation, and on Schwann cell survival and proliferation. A transection induces c-Jun and ATF-3 transcription in Schwann cells. These events are followed by Schwann cell activation of c-Jun in the injured nerve. The MAPK inhibitor U0126 blocked ERK1/2 activation and reduced Schwann cell proliferation as well as induction of c-Jun transcription. The JNK inhibitor SP600125 reduced Schwann cell proliferation, but did not affect the expression of ERK1/2 or injury-induced increases in c-Jun or ATF-3 levels. Importantly, nerve injury induces Schwann cell activation of c-Jun by phosphorylation, which, in contrast to in sensory neurons, is JNK independent. MAP kinases, other than JNK, can potentially activate c-Jun in Schwann cells following injury; information that is crucial to create new nerve reconstruction strategies. © 2014 Charlotta Lindwall Blom et al.
Marine S.,Merck And Co. |
Freeman J.,University College London |
Riccio A.,University College London |
Axenborg M.-L.,Cellectricon AB |
And 3 more authors.
Journal of Biomolecular Screening | Year: 2012
Primary neurons in culture are considered to be a highly relevant model in the study of neuronal development and activity. They can be cultivated and differentiated in vitro but are difficult to transfect using conventional methods. To address this problem, a capillary electroporation system called Cellaxess Elektra was developed for efficient and reproducible transfection of primary cortical and hippocampal neurons without significant impact on cell morphology and viability. The cells are transfected in any stage of differentiation and development, directly in cell culture plates. Genetic material is delivered in situ to as many as 384 samples at a time, which enables both high-throughput and high-quality screening for hard-to-transfect primary cells, meaning that gene function can be studied on a genome-wide scale in cells previously inaccessible to genetic manipulation. © 2012 Society for Laboratory Automation and Screening.
Nilsson Skold H.,Gothenburg University |
Aspengren S.,Cellectricon AB |
Wallin M.,Gothenburg University
Pigment Cell and Melanoma Research | Year: 2013
Physiological color change is important for background matching, thermoregulation as well as signaling and is in vertebrates mediated by synchronous intracellular transport of pigmented organelles in chromatophores. We describe functions of and animal situations where color change occurs. A summary of endogenous and external factors that regulate this color change in fish and amphibians is provided, with special emphasis on extracellular stimuli. We describe not only color change in skin, but also highlight studies on color change that occurs using chromatophores in other areas such as iris and on the inside of the body. In addition, we discuss the growing field that applies melanophores and skin color in toxicology and as biosensors, and point out research areas with future potential. © 2012 John Wiley & Sons A/S.
Cellectricon Ab | Date: 2012-07-23
Disclosed is a method for selective electrofusion of at least two fusion partners having cell-like membranes and cellular or subcellular dimensions, comprising the following steps: A) the fusion partners are brought into contact with each other and B) an electrical field of a strength sufficient to obtain fusion and highly focused on the fusion partners is applied. The fusion partners are independently selected from the group consisting of a single cell, a liposome, a proteoliposome, a synthetic vesicle, an egg cell, an enucleated egg cell, a sperm cell at any development stage and a plant protoplast.
Cellectricon Ab | Date: 2011-09-28
The invention provides a method for changing a solution environment locally around a cell-based biosensor. According to the method, a substrate is provided. The substrate comprises a chamber with the cell-based biosensor and the fluid. Further, the substrate comprises a plurality of channels, each channel comprising an outlet. According to the method, streams of fluid are delivered into the chamber, and at least two of the streams comprise different fluids. Further, the cell-based biosensor is scanned sequentially across the at least two streams, thereby altering the aqueous solution environment around the cell-based biosensor.
Cellectricon Ab | Date: 2011-09-28
The invention provides a method, in which a substrate is provided. The substrate comprises a chamber having a cell-based biosensor. The biosensor has a receptor which is activated by an agonist. Further, the substrate comprises a plurality of delivery channels delivering agonist, antagonist or buffer. Each channel comprises an outlet and delivers a substantially separate aqueous stream into the chamber. Further, each channel is in communication with a reservoir. The method further comprises selectively exposing the biosensor to a fluid stream from one or more channels.
Cellectricon Ab | Date: 2011-07-27
The invention provides a substrate for altering the solution environment around a sensor, e.g., formed by a cell or a portion of a cell, and a system formed by the substrate and a sensor. The substrate comprises a chamber for receiving the sensor and a plurality of channels. Each channel comprises an outlet and delivers a substantially separate fluid stream to a sensor in the chamber. At least one channel is in communication with a reservoir, e.g., a buffer reservoir or a sample reservoir.
Cellectricon Ab | Date: 2014-09-03
Apparatuses and methods of aligning at least one tip of a tip manifold with a plurality of wells of a multiwell plate. The tip manifold includes a plate, at least one tip (202) depending from the plate, a first tip alignment pin (210) depending from the plate, and a second tip alignment pin depending from the plate. The second tip alignment pin opposes the first tip alignment pin. The multiwell plate includes a body defining a plurality of non-porous wells for holding biological material, a first alignment hole (310,312), and a second alignment hole (310,312). The second alignment hole opposes the first alignment hole.