An epidemiological qualitative/quantitative SWOT-AHP analysis in order to highlight the positive or critical aspects of dental implants: A pilot study

OBJECTIVES

In recent years, dental implants are increasing in popularity due to their high success rate, demonstrated functionality, and aesthetic treatment results. Scientific research is very active in proposing improvements in the quality and survival of implants, taking into consideration various aspects. The objective of this study was to provide a holistic epidemiologic view of the state of dental implants, using a systematic approach based on a multimethod SWOT (Strengths, Weaknesses, Opportunities, and Threats) analysis and AHP (analytical hierarchical process) qualitative-quantitative analysis to identify the characteristics that can determine their success or failure.

MATERIALS AND METHODS

The study used the hybrid method of SWOT-AHP.

RESULTS

Analysis of the results showed that among strengths, the skill of the dentist was considered the most important factor, followed by the success of dental implants in the old people; among weaknesses, bruxism and chronic diseases were highlighted; for opportunities, biomechanical behavior, in terms of good mechanical strength and good tribological resistance to chemical and physical agents in the oral cavity, were considered the most important factors; finally, among threats, medical liability and biomechanical problems had equal weight.

CONCLUSIONS

This study applied a multimethod SWOT-AHP approach to bring out favorable or critical evidence on the topic of dental implants. In accordance with the result of the strategic vector identified in the Twisting zone Adjustment type section, showed that implant surgery is a widespread technique but always needs improvement to increase the likelihood of success and reduce the complications that can lead to implant failure.

A Narrative Review Exploring the Similarities between Cilento and the Already Defined "Blue Zones" in Terms of Environment, Nutrition, and Lifestyle: Can Cilento Be Considered an Undefined "Blue Zone"?

Longevity is rightly considered one of the greatest achievements of modern society, not only as a function of lifespan, but, more importantly, as a function of healthspan. There are Longevity Blue Zones (LBZs), regions around the world, such as in Okinawa, Japan; the Nicoya Peninsula, Costa Rica; Loma Linda, California; Icaria, Greece; and Ogliastra, Sardinia, that are characterized by a significant percentage of residents who live exceptionally long lives, often avoiding age-related disability to a significantly higher degree than in the Western way of life. Longevity is not a universal phenomenon, so if there are places in the world with characteristics similar to the LBZs, it is important to identify them in order to better understand what other factors, in addition to the known ones, might contribute to a long and healthy life. This narrative review aims to identify common factors between Cilento and the five LBZs, taking into account environmental, nutritional, and lifestyle factors. Articles from 2004 to the present, limited to studies published in English, German, and Italian, were searched in PubMed/Medline, Scopus, and Google Scholar. The co-authors agreed on 18 final reference texts. In order to evaluate the similarities between Cilento and the LBZs, a descriptive comparative approach was used. Cilento and the LBZs share several common factors, including a hilly altitude ranging from 355 to 600 m; a mild climate throughout the year, with temperatures between 17.4 and 23.5 degrees Celsius; traditional professions, such as agriculture and animal husbandry; and a predominantly Mediterranean or plant-based diet, with typical recipes based on legumes, tubers, vegetables, and extra virgin olive oil. Additionally, maintenance of strong intergenerational family relationships, religious devotion, and social relationships within the community are also prevalent. Given the similarities to Cilento, one might wonder if this is an LBZ waiting to be discovered. The lessons learned from this discovery could be applied to the general population to protect them from non-communicable chronic diseases and help slow the aging process.

Restoring Axonal Organelle Motility and Regeneration in Cultured FUS-ALS Motoneurons through Magnetic Field Stimulation Suggests an Alternative Therapeutic Approach

Amyotrophic lateral sclerosis (ALS) is a devastating motoneuron disease characterized by sustained loss of neuromuscular junctions, degenerating corticospinal motoneurons and rapidly progressing muscle paralysis. Motoneurons have unique features, essentially a highly polarized, lengthy architecture of axons, posing a considerable challenge for maintaining long-range trafficking routes for organelles, cargo, mRNA and secretion with a high energy effort to serve crucial neuronal functions. Impaired intracellular pathways implicated in ALS pathology comprise RNA metabolism, cytoplasmic protein aggregation, cytoskeletal integrity for organelle trafficking and maintenance of mitochondrial morphology and function, cumulatively leading to neurodegeneration. Current drug treatments only have marginal effects on survival, thereby calling for alternative ALS therapies. Exposure to magnetic fields, e.g., transcranial magnetic stimulations (TMS) on the central nervous system (CNS), has been broadly explored over the past 20 years to investigate and improve physical and mental activities through stimulated excitability as well as neuronal plasticity. However, studies of magnetic treatments on the peripheral nervous system are still scarce. Thus, we investigated the therapeutic potential of low frequency alternating current magnetic fields on cultured spinal motoneurons derived from induced pluripotent stem cells of FUS-ALS patients and healthy persons. We report a remarkable restoration induced by magnetic stimulation on axonal trafficking of mitochondria and lysosomes and axonal regenerative sprouting after axotomy in FUS-ALS in vitro without obvious harmful effects on diseased and healthy neurons. These beneficial effects seem to derive from improved microtubule integrity. Thus, our study suggests the therapeutic potential of magnetic stimulations in ALS, which awaits further exploration and validation in future long-term in vivo studies.

Analysis of Electric Field Stimulation in Blue Light Stressed 661W Cells

Though electrical stimulation is used as a therapeutic approach to treat retinal and spinal injuries, many protective mechanisms at cellular level have not been elucidated. We performed a detailed analysis of cellular events in blue light (Li) stressed 661W cells, which were subjected to direct current electric field (EF) stimulation. Our findings revealed that EF stimulation induced protective effects in 661W cells from Li-induced stress by multiple defense mechanisms, such as increase in mitochondrial activity, gain in mitochondrial potential, increase in superoxide levels, and the activation of unfolded protein response (UPR) pathways, all leading to an enhanced cell viability and decreased DNA damage. Here, our genetic screen results revealed the UPR pathway to be a promising target to ameliorate Li-induced stress by EF stimulation. Thus, our study is important for a knowledgeable transfer of EF stimulation into clinical application.

The significance of bioelectricity on all levels of organization of an organism. Part 1: From the subcellular level to cells

Bioelectricity plays an essential role in the structural and functional organization of biological organisms. In this first article of our three-part series, we summarize the importance of bioelectricity for the basic structural level of biological organization, i.e. from the subcellular level (charges, ion channels, molecules and cell organelles) to cells.

Induction of vascular endothelial growth factor-A165a in human retinal and endothelial cells in response to glyoxal

Low-density lipoprotein (LDL) apheresis is effective and safe for patients with diabetes, proteinuria, and dyslipidemia. Diabetes mellitus is accompanied by ocular microvascular complications like retinal neovascularization or diabetic macular edema. These are leading causes of blindness and can be mediated by abnormal vessel growth and increased vascular permeability due to elevated levels of vascular endothelial growth factor (VEGF) in diabetic patients. In this study, we established methods to study the expression of different VEGF isoforms in human retinal and endothelial cells. The VEGF-A_165a isoform is much higher expressed in retinal cells, compared to endothelial cells. Stimulation with glyoxal as a model of oxidative stress under diabetic conditions lead to a pronounced induction of VEGF-A_165a in human retinal and endothelial cells. These data suggest that diabetes and oxidative stress induce VEGF-A isoforms which could be relevant in regulating the ingrowths of novel blood vessels into the retina in diabetic patients.

Understanding the Feedback Loops between Energy, Matter and Life

This review gathers recent findings in biophysics that shed light on the biological principle of self-organization, spanning from molecules to more complicated systems with higher information processing capacity. The focus is on "feedback loops" from information and matter to an exchange component with a more fundamental meaning than "cybernetic regulation" and "maintenance of homeostasis". This article proposes that electric and electromagnetic forces are the most important mediators over large distances. Field-like mediation is distinguished from cell-to-cell communication by special electric- or ion-guiding mechanisms that create additional pathways to the "classical" mediators such as nerve conduction or blood flow. Resonance phenomena from phonons and photons in the visible range will be discussed in relation to organelles, cytoskeletal elements and molecules. In this context, the aqueous surrounding of molecules and cells is an important aspect. Many of these phenomena are caused by quantum physics, such as the tunneling of electrons in enzymes or in other coherent working systems. This suggests that quantum information processing is also spread over large-scale areas of an organism.

Clinical Status, Nutritional Behavior, and Lifestyle, and Determinants of Community Well-Being of Patients from the Perspective of Physicians: A Cross-Sectional Study of Young Older Adults, Nonagenarians, and Centenarians in Salerno and Province, Italy

Longevity is rightly considered one of the greatest achievements of modern society. Biomedical research has shown that aging is the major risk factor for many diseases, so to find the right answers to aging it is necessary to identify factors that can positively influence longevity. This study investigated the clinical status, nutritional behavior, lifestyle, and social and community determinants of the well-being of young older adults and nonagenarians/centenarians in Salerno and province through the judgment of their physicians. Data were collected through an online survey. Multivariate Poisson and logistic regression models were used to calculate significant predictors of the outcomes of interest. The interesting finding was that cardiovascular disease was a risk factor for young older adults, while it was a protective factor for nonagenarians/centenarians, meaning that as age increased, heart problems tended to decrease. Certain foods were found to be a significant protective factor for both young older adult and nonagenarian-centenarian patients. In addition, psychosomatic disorders were found to be determinant for the young older adults, while depression was a risk factor for the nonagenarians/centenarians because they were not always gratified by their long lives and often felt like a burden on the family. The protective significant variable among the determinants of community well-being for both young older adults and nonagenarians/centenarians was the retention of honorary achievement. Based on our results, we are able to support the hypothesis of a difference between the young older adults and the nonagenarians/centenarians in clinical status, nutritional behaviors, lifestyle, and determinants of community well-being. However, societies need more social and educational programs that are able to build "a new idea of old age" by improving and supporting the young older adults and the nonagenarians/centenarians, with the goal of intergenerational solidarity, well-being, and social inclusion, as well as preventive interventions on lifestyles and nutrition, which will allow us to provide a new key to understanding aging.

[New master's program: multiple sclerosis management]

Der neue Studiengang „Multiple Sklerose Management“ richtet sich an Ärzt*innen, Therapeut*innen, Pflegepersonal, Wissenschaftler*innen, Apotheker*innen, Psycholog*innen und Biolog*innen, die sich im Bereich der Multiplen Sklerose (MS) spezialisieren wollen. Nach erfolgreicher Akkreditierung im Jahr 2019 befindet sich die erste Matrikel seit 2020 in dem von der Dresden International University (DIU) angebotenen Masterstudiengang. Über eine Dauer von 4 Semestern kann er berufsbegleitend und größtenteils digital absolviert werden. Der Masterstudiengang gliedert sich in 6 Module mit den Schwerpunkten Grundlagen, Klinik und Diagnostik, MS-Studien und Statistik, krankheitsmodifizierende und symptomatische Therapie, Krankheitsmonitoring und Dokumentation. Der Unterricht beinhaltet theoretische Anteile und zahlreiche Praxiseinheiten. Ein weiteres Ziel ist es, aus wissenschaftlichen Publikationen und klinischen Studien therapeutische Interventionspläne und Problemlösungsstrategien abzuleiten, sie weiterzuentwickeln und in der Patientenversorgung anzuwenden. Die Dozent*innen stammen aus Deutschland, Österreich und der Schweiz und sind überwiegend Professor*innen. Die Schirmherrschaft für den Studiengang übernimmt die Deutsche Multiple Sklerose Gesellschaft. Dieser Beitrag stellt den Studiengang im Detail vor.

A short review on the influence of magnetic fields on neurological diseases

This study reviews the use of magnetic and electromagnetic fields (EMF), pulsed electromagnetic fields (PEMF), and transcranial magnetic stimulation (TMS) in Parkinson's disease, Alzheimer's disease (AD), or Multiple Sclerosis (MS). The Introduction provides a review of EMF, PEMF, and TMS based on clinical observations. This is followed by a description of the basic principles of these treatments and a literature review on possible mechanisms describing the coupling of these treatments with biological responses. These response mechanisms include the cell membrane and its embedded receptors, channels and pumps, as well as signaling cascades within the cell and links to cell organelles. We also discuss the magnetic contribution to coupling EMF, as well as the recent finding of cryptochrome as a putative magnetosensor. Our conclusion summarizes the complex network of causal factors elicited by EMF such as those arising from the cell membrane via signaling cascades to radical oxygen species, nitric oxide, growth factors, cryptochromes and other mechanisms involving epigenetic and genetic changes.

Innovation in Digital Education: Lessons Learned from the Multiple Sclerosis Management Master's Program

Since 2020, the master’s program “Multiple Sclerosis Management” has been running at Dresden International University, offering structured training to become a multiple sclerosis specialist. Due to the COVID-19 pandemic, many planned teaching formats had to be changed to online teaching. The subject of this paper was the investigation of a cloud-based digital hub and student evaluation of the program. Authors analyzed use cases of computer-supported collaborative learning and student evaluation of courses and modules using the Gioia method and descriptive statistics. The use of a cloud-based digital hub as a central data platform proved to be highly successful for learning and teaching, as well as for close interaction between lecturers and students. Students rated the courses very positively in terms of content, knowledge transfer and interaction. The implementation of the master’s program was successful despite the challenges of the COVID-19 pandemic. The resulting extensive use of digital tools demonstrates the “new normal” of future learning, with even more emphasis on successful online formats that also increase interaction between lecturers and students in particular. At the same time, there will continue to be tailored face-to-face events to specifically increase learning success.

Pathophysiological Changes in the Enteric Nervous System of Rotenone-Exposed Mice as Early Radiological Markers for Parkinson's Disease

Parkinson's disease (PD) is known to involve the peripheral nervous system (PNS) and the enteric nervous system (ENS). Functional changes in PNS and ENS appear early in the course of the disease and are responsible for some of the non-motor symptoms observed in PD patients like constipation, that can precede the appearance of motor symptoms by years. Here we analyzed the effect of the pesticide rotenone, a mitochondrial Complex I inhibitor, on the function and neuronal composition of the ENS by measuring intestinal contractility in a tissue bath and by analyzing related protein expression. Our results show that rotenone changes the normal physiological response of the intestine to carbachol, dopamine and electric field stimulation (EFS). Changes in the reaction to EFS seem to be related to the reduction in the cholinergic input but also related to the noradrenergic input, as suggested by the non-adrenergic non-cholinergic (NANC) reaction to the EFS in rotenone-exposed mice. The magnitude and direction of these alterations varies between intestinal regions and exposure times and is associated with an early up-regulation of dopaminergic, cholinergic and adrenergic receptors and an irregular reduction in the amount of enteric neurons in rotenone-exposed mice. The early appearance of these alterations, that start occurring before the substantia nigra is affected in this mouse model, suggests that these alterations could be also observed in patients before the onset of motor symptoms and makes them ideal potential candidates to be used as radiological markers for the detection of Parkinson's disease in its early stages.

VEGF-Trap is a potent modulator of vasoregenerative responses and protects dopaminergic amacrine network integrity in degenerative ischemic neovascular retinopathy

Retinal hypoxia triggers abnormal vessel growth and microvascular hyper-permeability in ischemic retinopathies. Whereas vascular endothelial growth factor A (VEGF-A) inhibitors significantly hinder disease progression, their benefits to retinal neurons remain poorly understood. Similar to humans, oxygen-induced retinopathy (OIR) mice exhibit severe retinal microvascular malformations and profound neuronal dysfunction. OIR mice are thus a phenocopy of human retinopathy of prematurity, and a proxy for investigating advanced stages of proliferative diabetic retinopathy. Hence, the OIR model offers an excellent platform for assessing morpho-functional responses of the ischemic retina to anti-angiogenic therapies. Using this model, we investigated the retinal responses to VEGF-Trap (Aflibercept), an anti-angiogenic agent recognizing ligands of VEGF receptors 1 and 2 that possesses regulatory approval for the treatment of neovascular age-related macular degeneration, macular edema secondary to retinal vein occlusion and diabetic macular edema. Our results indicate that Aflibercept not only reduces the severity of retinal microvascular aberrations but also significantly improves neuroretinal function. Aflibercept administration significantly enhanced light-responsiveness, as revealed by electroretinographic examinations, and led to increased numbers of dopaminergic amacrine cells. Additionally, retinal transcriptional profiling revealed the concerted regulation of both angiogenic and neuronal targets, including transcripts encoding subunits of transmitter receptors relevant to amacrine cell function. Thus, Aflibercept represents a promising therapeutic alternative for the treatment of further progressive ischemic retinal neurovasculopathies beyond the set of disease conditions for which it has regulatory approval. Cover Image for this issue: doi: 10.1111/jnc.14743.

Biophysical mechanisms complementing "classical" cell biology

This overview addresses phenomena in cell- and molecular biology which are puzzling by their fast and highly coordinated way of organization. Generally, it appears that informative processes probably involved are more on the biophysical than on the classical biochemical side. The coordination problem is explained within the first part of the review by the topic of endogenous electrical phenomena. These are found e.g. in fast tissue organization and reorganization processes like development, wound healing and regeneration. Here, coupling into classical biochemical signaling and reactions can be shown by modern microscopy, electronics and bioinformatics. Further, one can follow the triggered reactions seamlessly via molecular biology till into genetics. Direct observation of intracellular electric processes is very difficult because of e.g. shielding through the cell membrane and damping by other structures. Therefore, we have to rely on photonic and photon - phonon coupling phenomena like molecular vibrations, which are addressed within the second part. Molecules normally possess different charge moieties and thus small electromagnetic (EMF) patterns arise during molecular vibration. These patterns can now be measured best within the optical part of the spectrum - much less in the lower terahertz till kHz and lower Hz part (third part of this review). Finally, EMFs facilitate quantum informative processes in coherent domains of molecular, charge and electron spin motion. This helps to coordinate such manifold and intertwined processes going on within cells, tissues and organs (part 4). Because the phenomena described in part 3 and 4 of the review still await really hard proofs we need concerted efforts and a combination of biophysics, molecular biology and informatics to unravel the described mysteries in "physics of life".

The human platysma contains numerous muscle spindles

The mimic muscles are usually described as containing no muscle spindles. In the present publication the human platysma was reinvestigated concerning its content of corpuscular sensors. Serial sections through the platysma of seven donors revealed numerous muscle spindles but no Pacini corpuscules. The muscle spindles were located in the cranial two-thirds of the platysma, and were evenly distributed with a tendency to have more spindles in the lateral part of the muscle. Immunohistochemical staining with S46 antibodies revealed a predominance of nuclear bag fibers. The results point to an extended function of the platysma as an afferent center of the lower face mimic muscles.

Changes in the sympathetic innervation of the gut in rotenone treated mice as possible early biomarker for Parkinson's disease

Introduction

Involvement of the peripheral nervous system (PNS) is relatively common in Parkinson’s disease (PD) patients. PNS alterations appear early in the course of the disease and are responsible for some of the non-motor symptoms observed in PD patients. In previous studies, we have shown that environmental toxins can trigger the disease by acting on the enteric nervous system.

Material and methods

Here, we analyzed the effect of mitochondrial Complex I inhibition on sympathetic neuritis in vivo and sympathetic neurons in vitro. Combining in vivo imaging and protein expression profiling.

Results

we found that rotenone, a widely used mitochondrial Complex I inhibitor decreases the density of sympathetic neurites innervating the gut in vivo, while in vitro, it induces the redistribution of intracellular alpha-synuclein and neurite degeneration. Interestingly, sympathetic neurons are much more resistant to rotenone exposure than mesencephalic dopaminergic neurons.

Conclusion

Altogether, these results suggest that enteric sympathetic denervation could be an initial pre-motor alteration in PD progression that could be used as an early biomarker of the disease.

Electronic supplementary material

The online version of this article (doi:10.1007/s10286-016-0358-6) contains supplementary material, which is available to authorized users.

Thermo-responsive cell culture carriers based on poly(vinyl methyl ether)-the effect of biomolecular ligands to balance cell adhesion and stimulated detachment

Two established material systems for thermally stimulated detachment of adherent cells were combined in a cross-linked polymer blend to merge favorable properties. Through this approach poly(N-isopropylacrylamide) (PNiPAAm) with its superior switching characteristic was paired with a poly(vinyl methyl ether)-based composition that allows adjusting physico-chemical and biomolecular properties in a wide range. Beyond pure PNiPAAm, the proposed thermo-responsive coating provides thickness, stiffness and swelling behavior, as well as an apposite density of reactive sites for biomolecular functionalization, as effective tuning parameters to meet specific requirements of a particular cell type regarding initial adhesion and ease of detachment. To illustrate the strength of this approach, the novel cell culture carrier was applied to generate transplantable sheets of human corneal endothelial cells (HCEC). Sheets were grown, detached, and transferred onto planar targets. Cell morphology, viability and functionality were analyzed by immunocytochemistry and determination of transepithelial electrical resistance (TEER) before and after sheet detachment and transfer. HCEC layers showed regular morphology with appropriate TEER. Cells were positive for function-associated marker proteins ZO-1, Na+/K+-ATPase, and paxillin, and extracellular matrix proteins fibronectin, laminin and collagen type IV before and after transfer. Sheet detachment and transfer did not impair cell viability. Subsequently, a potential application in ophthalmology was demonstrated by transplantation onto de-endothelialized porcine corneas in vitro. The novel thermo-responsive cell culture carrier facilitates the generation and transfer of functional HCEC sheets. This paves the way to generate tissue engineered human corneal endothelium as an alternative transplant source for endothelial keratoplasty.

Endogenous electric fields as guiding cue for cell migration

This review covers two topics: (1) "membrane potential of low magnitude and related electric fields (bioelectricity)" and (2) "cell migration under the guiding cue of electric fields (EF)."Membrane potentials for this "bioelectricity" arise from the segregation of charges by special molecular machines (pumps, transporters, ion channels) situated within the plasma membrane of each cell type (including eukaryotic non-neural animal cells). The arising patterns of ion gradients direct many cell- and molecular biological processes such as embryogenesis, wound healing, regeneration. Furthermore, EF are important as guiding cues for cell migration and are often overriding chemical or topographic cues. In osteoblasts, for instance, the directional information of EF is captured by charged transporters on the cell membrane and transferred into signaling mechanisms that modulate the cytoskeleton and motor proteins. This results in a persistent directional migration along an EF guiding cue. As an outlook, we discuss questions concerning the fluctuation of EF and the frequencies and mapping of the "electric" interior of the cell. Another exciting topic for further research is the modeling of field concepts for such distant, non-chemical cellular interactions.

Sutureless fixation of amniotic membrane for therapy of ocular surface disorders

Amniotic membrane is applied to the diseased ocular surface to stimulate wound healing and tissue repair, because it releases supportive growth factors and cytokines. These effects fade within about a week after application, necessitating repeated application. Generally, amniotic membrane is fixed with sutures to the ocular surface, but surgical intervention at the inflamed or diseased site can be detrimental. Therefore, we have developed a system for the mounting of amniotic membrane between two rings for application to a diseased ocular surface without surgical intervention (sutureless amniotic membrane transplantation). With this system, AmnioClip, amniotic membrane can be applied like a large contact lens. First prototypes were tested in an experiment on oneself for wearing comfort. The final system was tested on 7 patients in a pilot study. A possible influence of the ring system on the biological effects of amniotic membrane was analyzed by histochemistry and by analyzing the expression of vascular endothelial growth factor-A (VEGF-A), hepatocyte growth factor (HGF), fibroblast growth factor 2 (FGF 2) and pigment epithelium-derived factor (PEDF) from amniotic membranes before and after therapeutic application. The final product, AmnioClip, showed good tolerance and did not impair the biological effects of amniotic membrane. VEGF-A and PEDF mRNA was expressed in amniotic membrane after storage and mounting before transplantation, but was undetectable after a 7-day application period. Consequently, transplantation of amniotic membranes with AmnioClip provides a sutureless and hence improved therapeutic strategy for corneal surface disorders.

Imaging of nanoparticle-labeled stem cells using magnetomotive optical coherence tomography, laser speckle reflectometry, and light microscopy

Cell transplantation and stem cell therapy are promising approaches for regenerative medicine and are of interest to researchers and clinicians worldwide. However, currently, no imaging technique that allows three-dimensional in vivo inspection of therapeutically administered cells in host tissues is available. Therefore, we investigate magnetomotive optical coherence tomography (MM-OCT) of cells labeled with magnetic particles as a potential noninvasive cell tracking method. We develop magnetomotive imaging of mesenchymal stem cells for future cell therapy monitoring. Cells were labeled with fluorescent iron oxide nanoparticles, embedded in tissue-mimicking agar scaffolds, and imaged using a microscope setup with an integrated MM-OCT probe. Magnetic particle-induced motion in response to a pulsed magnetic field of 0.2 T was successfully detected by OCT speckle variance analysis, and cross-sectional and volumetric OCT scans with highlighted labeled cells were obtained. In parallel, fluorescence microscopy and laser speckle reflectometry were applied as two-dimensional reference modalities to image particle distribution and magnetically induced motion inside the sample, respectively. All three optical imaging modalities were in good agreement with each other. Thus, magnetomotive imaging using iron oxide nanoparticles as cellular contrast agents is a potential technique for enhanced visualization of selected cells in OCT.

NHE3 phosphorylation via PKCη marks the polarity and orientation of directionally migrating cells

Endogenous electric fields (EF) may provide an overriding cue for directional cell migration during wound closure. Perceiving a constant direction requires active sodium-hydrogen exchanger (pNHE3) at the leading edge of HEK 293 cells but its activation mechanism is not yet fully understood. Because protein kinase C (PKC) is required in electrotaxis, we asked whether NHE3 is activated by PKC during wound healing. Using pharmacological (pseudosubstrate and edelfosine) inhibition, we showed that inhibition of PKCη isoform impairs directional cell migration in HEK 293 cells in the presence of a persistent directional cue (0.25-0.3 V/mm of EF for 2 h). Further, we found that pNHE3 forms complexes with both PKCη and ɣ-tubulin, suggesting that these molecules may regulate the microtubule-organizing center. In addition, cellular pNHE3 content was reduced significantly when PKCη was inhibited during directional cell migration. Taken together, these data suggest that PKCη-dependent phosphorylation of NHE3 and the formation of pNHE3/PKCη/ɣ-tubulin complexes at the leading edge of the cell are required for directional cell migration in an EF.

Quality assessment of corneal storage media and their components

BACKGROUND

To keep the loss of endothelial cell density in donor corneas to a minimum, a storage medium which is adjusted to their nutritional needs is necessary. Different media, used either serum-supplemented or serum-free, are available. The quality of medium- and serum-batches as well as support of endothelial cell viability by the medium are to be tested with a quality assured screening system that allows routine examination.

METHODS

A screening system was developed which is based on cell-culture tests with the well-established human corneal endothelial cell line HCEC-12, and therefore can be performed without the need for donor corneas. The cells are plated at a defined density in cell-culture dishes, and are cultured for a defined period of time in the test media. Evaluation is carried out by assaying cell count, activity of cell metabolism (resazurin conversion), and determining the number of apoptotic and necrotic cells (combined vital staining with YO-PRO®-1/propidium iodide and subsequent flow cytometry).

RESULTS

Human corneal endothelial cells that are cultured in a medium which is adjusted to their nutritional needs achieve higher cell numbers and show a higher metabolic rate. Simultaneously, the percentage of apoptotic and necrotic cells is lower. The screening system developed in this study allows for easy and reliable detection of slightest differences between different media, different processing steps for same media, and different supplements, as well as different serum batches.

CONCLUSIONS

The differentiated results show that the screening system is sensitive enough to show even minor quality differences. Therefore, it is more suitable than the hitherto commonly used growth assay with primary, mostly porcine, corneal endothelial cells.

Tissue engineering of the corneal endothelium: a review of carrier materials

Functional impairment of the human corneal endothelium can lead to corneal blindness. In order to meet the high demand for transplants with an appropriate human corneal endothelial cell density as a prerequisite for corneal function, several tissue engineering techniques have been developed to generate transplantable endothelial cell sheets. These approaches range from the use of natural membranes, biological polymers and biosynthetic material compositions, to completely synthetic materials as matrices for corneal endothelial cell sheet generation. This review gives an overview about currently used materials for the generation of transplantable corneal endothelial cell sheets with a special focus on thermo-responsive polymer coatings.

Stress reaction in outer segments of photoreceptors after blue light irradiation

The retina is prone to oxidative stress from many factors which are also involved in the pathogenesis of degenerative diseases. In this study, we used the application of blue light as a physiological stress factor. The aim of this study was to identify the major source of intracellular ROS that mediates blue light-induced detrimental effects on cells which may lead to cytotoxicity. We hypothesized that outer segments are the major source of blue light induced ROS generation. In photoreceptors, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox) enzymes and the recently found respiratory chain complexes may represent a major source for reactive oxygen species (ROS), beside mitochondria and chromophores. Therefore, we investigated this hypothesis and analysed the exact localization of the ROS source in photoreceptors in an organotypic culture system for mouse retinas.

Whole eyeball cultures were irradiated with visible blue light (405 nm) with an output power of 1 mW/cm². Blue light impingement lead to an increase of ROS production (detected by H₂DCFDA in live retinal explants), which was particularly strong in the photoreceptor outer segments. Nox-2 and Nox-4 proteins are sources of ROS in blue light irradiated photoreceptors; the Nox inhibitor apocynin decreased ROS stimulated by blue light. Concomitantly, enzyme SOD-1, a member of the antioxidant defense system, indicator molecules of protein oxidation (CML) and lipid oxidation (MDA and 4-HNE) were also increased in the outer segments.

Interestingly, outer segments showed a mitochondrial-like membrane potential which was demonstrated using two dyes (JC-1 and TMRE) normally exclusively associated with mitochondria. As in mitochondria, these dyes indicated a decrease of the membrane potential in hypoxic states or cell stress situations.

The present study demonstrates that ROS generation and oxidative stress occurs directly in the outer segments of photoreceptors after blue light irradiation.

Implications of Parkinson's disease pathophysiology for the development of cell replacement strategies and drug discovery in neurodegenerative diseases

Parkinson's disease (PD) is a progressive neurodegenerative disorder traditionally characterized by the loss of dopaminergic neurons in the substantia nigra (SN) at the midbrain. The potential use of adult or embryonic stem cells, induced pluriputent stem (iPS) cells and endogenous neurogenesis in cell replacement strategies has lead to numerous studies and clinical trials in this direction. It is now possible to differentiate stem cells into dopaminergic neurons in vitro and clinical trials have shown an improvement in PD-related symptoms after intra-striatal embryonic transplants and acceptable cell survival rates on the mid term. However, clinical improvement is transitory and associated with a strong placebo effect. Interestingly, recent pathological studies in PD patients who received embryonic stem cells show that in PD patients, grafted neurons show PD-related pathology. In this manuscript we review the latest findings regarding PD pathophysiology and give an outlook on the implications of these findings in how cell replacement strategies for PD treatment should be tested. These include changes in the type of animal models used, the preparation/conditioning of the cells before intracerebral injection, specially regarding backbone chronic diseases in iPS cells and determining the optimal proliferation, survival, differentiation and migration capacity of the grafted cells.

Immunohistochemical localization and characterization of putative mesenchymal stem cell markers in the retinal capillary network of rodents

Perivascular cells of microvascular niches are the prime candidates for being a reservoire of mesenchymal stem cell (MSC)-like cells in many tissues and organs that could serve as a potential source of cells and a target of novel cell-based therapeutic approaches. In the present study, by utilising typical markers of pericytes (neuronal-glial antigen 2, NG2, a chondroitin sulphate proteoglycan) and those of MSCs (CD146 and CD105) and primitive pluripotent cells (sex-determining region Y-box 2, Sox2), the phenotypic traits and the distribution of murine and rat retinal perivascular cells were investigated in situ. Our findings indicate that retinal microvessels of juvenile rodents are highly covered by NG2-positive branching processes of pericytic (perivascular) cells that are less prominent in mature capillary networks of the adult retina. In the adult rodent retinal vascular bed, NG2 labeling is mainly confined to membranes of the cell body resulting in a pearl-chain-like distribution along the vessels. Retinal pericytes, which were identified by their morphology and NG2 expression, simultaneously express CD146. Furthermore, CD146-positive cells located at small arteriole-to-capillary branching points appear more intensely stained than elsewhere. Evidence for a differential expression of the two markers around capillaries that would hint at a clonal heterogeneity among pericytic cells, however, is lacking. In contrast, the expression of CD105 is exclusively restricted to vascular endothelial cells and Sox2 is detected neither in perivascular nor in endothelial cells. In dissociated retinal cultures, however, simultaneous expression of NG2 and CD105 was observed. Collectively, our data indicate that vascular wall resident retinal pericytes share some phenotypic features (i.e. CD146 expression) with archetypal MSCs, which is even more striking in dissociated retinal cultures (i.e. CD105 expression). These findings might have implications for the treatment of retinal pathologies.

Overexpression of human HMW FGF-2 but not LMW FGF-2 reduces the cytotoxic effect of lentiviral gene transfer in human corneal endothelial cells

PURPOSE

Recently, insertion of immuno-modulatory or anti-apoptotic genes into corneal endothelial cells (HCECs) came into focus. Basic FGF-2 occurs in one secreted (low molecular weight, LMW, 18 kD) and four nuclear (high molecular weight, HMW, 22-34 kD) isoforms. HMW isoforms are known differentiation and survival factors, while LMW FGF-2 is a known mitogen. The effect of FGF-2 overexpression of each of the five known isoforms on HCEC cell survival after lentiviral gene transfer in different culture media was investigated.

METHODS

Cells were transduced with lentiviral vectors encoding for each of the five FGF-2 isoforms. Transduction efficiency and expression of individual FGF-2 isoforms was assessed by marker gene transfer and western blotting. Primary HCECs were cultured and transduced in four different media previously described for HCEC cultivation or corneal organ cultivation. Cytotoxic effect of virus infection and a possible rescue effect of FGF-2 overexpression were determined by resazurin conversion assay.

RESULTS

Transduction with FGF-2 encoding lentiviral vectors resulted in overexpression of the respective isoform in all tested cell populations. Western blotting after total cell lysis proved nuclear localization of transgenic HMW isoforms. Overexpression of HMW FGF-2-especially 34 kD FGF-2-reduced lentiviral cytotoxicity, while overexpression of LMW FGF-2 aggravated viral cytotoxicity.

CONCLUSIONS

Cytotoxicity of lentiviral gene transfer in corneal endothelial cells may be reduced by using bicistronic vectors that encode for the target gene and the 34-kD isoform of human FGF-2. Such cotransduction of a survival factor may increase cell survival after gene transfer, thereby improving gene therapeutic approaches.

Multi-level communication of human retinal pigment epithelial cells via tunneling nanotubes

Background

Tunneling nanotubes (TNTs) may offer a very specific and effective way of intercellular communication. Here we investigated TNTs in the human retinal pigment epithelial (RPE) cell line ARPE-19. Morphology of TNTs was examined by immunostaining and scanning electron microscopy. To determine the function of TNTs between cells, we studied the TNT-dependent intercellular communication at different levels including electrical and calcium signalling, small molecular diffusion as well as mitochondrial re-localization. Further, intercellular organelles transfer was assayed by FACS analysis.

Methodology and Principal Findings

Microscopy showed that cultured ARPE-19 cells are frequently connected by TNTs, which are not attached to the substratum. The TNTs were straight connections between cells, had a typical diameter of 50 to 300 nm and a length of up to 120 µm. We observed de novo formation of TNTs by diverging from migrating cells after a short time of interaction. Scanning electron microscopy confirmed characteristic features of TNTs. Fluorescence microscopy revealed that TNTs between ARPE-19 cells contain F-actin but no microtubules. Depolymerisation of F-actin, induced by addition of latrunculin-B, led to disappearance of TNTs. Importantly, these TNTs could function as channels for the diffusion of small molecules such as Lucifer Yellow, but not for large molecules like Dextran Red. Further, organelle exchange between cells via TNTs was observed by microscopy. Using Ca²⁺ imaging we show the intercellular transmission of calcium signals through TNTs. Mechanical stimulation led to membrane depolarisation, which expand through TNT connections between ARPE-19 cells. We further demonstrate that TNTs can mediate electrical coupling between distant cells. Immunolabelling for Cx43 showed that this gap junction protein is interposed at one end of 44% of TNTs between ARPE-19 cells.

Conclusions and Significance

Our observations indicate that human RPE cell line ARPE-19 cells communicate by tunneling nanotubes and can support different types of intercellular traffic.

Fgf signaling is required for photoreceptor maintenance in the adult zebrafish retina

Fibroblast growth factors (Fgf) are secreted signaling molecules that have mitogenic, patterning, neurotrophic and angiogenic properties. Their importance during embryonic development in patterning and morphogenesis of the vertebrate eye is well known, but less is known about the role of Fgfs in the adult vertebrate retina. To address Fgf function in adult retina, we determined the spatial distribution of components of the Fgf signaling pathway in the adult zebrafish retina. We detected differential expression of Fgf receptors, ligands and downstream Fgf targets within specific retinal layers. Furthermore, we blocked Fgf signaling in the retina, by expressing a dominant negative variant of Fgf receptor 1 conditionally in transgenic animals. After blocking Fgf signaling we observe a fast and progressive photoreceptor degeneration and disorganization of retinal tissue, coupled with cell death in the outer nuclear layer. Following the degeneration of photoreceptors, a profound regeneration response is triggered that starts with proliferation in the inner nuclear layer. Ultimately, rod and cone photoreceptors are regenerated completely. Our study reveals the requirement of Fgf signaling to maintain photoreceptors and for proliferation during regeneration in the adult zebrafish retina.

Pseudotyping and culture conditions affect efficiency and cytotoxicity of retroviral gene transfer to human corneal endothelial cells

PURPOSE

To evaluate retroviral vectors as a tool to transduce normal human corneal endothelial cells (HCECs) and to optimize transduction to increase gene transfer efficiency.

METHODS

Enhanced green fluorescent protein (EGFP) encoding retroviral vectors based on HIV-1 or murine leukemia virus (MLV), pseudotyped with either vesicular stomatitis virus glycoprotein (VSV-G) or a modified foamy virus envelope protein (FV Env), and prototype foamy virus (PFV) were produced. Transduction was performed in four HCEC culture media that were previously described for specific cultivation of HCECs or organ culture of donor corneas, namely enriched HCEC growth medium F99(HCEC), its unsupplemented basal medium F99, MEM + 2% fetal calf serum (FCS) (MEM), and Human Endothelial-SFM (SFM). Transduction efficiency was evaluated by marker gene transfer assay, and cytotoxic effects of virus infection were evaluated by means of resazurin conversion assay.

RESULTS

PFV- and HIV-1-based vectors showed superior transduction efficiency compared with MLV-based vectors. Pseudotyping with a modified FV Env increased transduction efficiency compared with pseudotyping with VSV-G. In medium SFM, transduction efficiency of PFV, HIV-1-/FV Env, and MLV-based vectors was markedly reduced compared with the other culture media. When cells were cultured in F99-based media, cell viability was reduced by retroviral transduction compared with uninfected or mock infected controls, but remained unaffected when cells were cultured in SFM and was even increased when cells were cultured in MEM.

CONCLUSIONS

HIV-1-based vectors pseudotyped with FV Env can efficiently be used to transduce primary HCECs in vitro. However, transduction efficiency is dependent on culture conditions and impairs metabolic activity and viability of HCECs in vitro.

Blue light stress in retinal neuronal (R28) cells is dependent on wavelength range and irradiance

The aim of our study was to elucidate the role of wavelength and irradiance in blue light retinal damage. We investigated the impact of blue light emitted from light-emitting diode (LED) modules with peaks at either 411nm (half bandwidth 17nm) or 470nm (half bandwidth 25nm) at defined irradiances of 0.6, 1.5 and 4.5W/m(2) for 411nm and 4.5W/m(2) for 470nm on retinal neuronal (R28) cells in vitro. We observed a reduction in metabolic activity and transmembrane potential of mitochondria when cells were irradiated at 411nm at higher irradiances. Furthermore, production of mitochondrial superoxide radicals increased significantly when cells were irradiated with 411nm light at 4.5W/m(2) . In addition, such irradiation caused an activation of the antioxidative glutathion system. Using vital staining, flow cytometry and western blotting, we were able to show that apoptosis only took place when cells were exposed to 411nm blue light at higher irradiances; necrosis was not observed. Enhanced caspase-3 cleavage product levels confirmed that this effect was dependent on light irradiance. Significant alterations of the above-mentioned parameters were not observed when cells were irradiated with 471nm light despite a high irradiance of 4.5W/m(2) , indicating that the cytotoxic effect of blue light is highly dependent on wavelength. The observed phenomena in R28 cells at 411nm (4.5W/m(2) ) point to an apoptosis pathway elicited by direct mitochondrial damage and increased oxidative stress. Thus, light of 411nm should act via impairment of mitochondrial function by compromising the metabolic situation of these retinal neuronal cells.

Retinal pigment epithelium cell alignment on nanostructured collagen matrices

We investigated attachment and migration of human retinal pigment epithelial cells (primary, SV40-transfected and ARPE-19) on nanoscopically defined, two-dimensional matrices composed of parallel-aligned collagen type I fibrils. These matrices were used non-cross-linked (native) or after riboflavin/UV-A cross-linking to study cell attachment and migration by time-lapse video microscopy. Expression of collagen type I and IV, MMP-2 and of the collagen-binding integrin subunit α(2) were examined by immunofluorescence and Western blotting. SV40-RPE cells quickly attached to the nanostructured collagen matrices and aligned along the collagen fibrils. However, they disrupted both native and cross-linked collagen matrices within 5 h. Primary RPE cells aligned more slowly without destroying either native or cross-linked substrates. Compared to primary RPE cells, ARPE-19 cells showed reduced alignment but partially disrupted the matrices within 20 h after seeding. Expression of the collagen type I-binding integrin subunit α(2) was highest in SV40-RPE cells, lower in primary RPE cells and almost undetectable in ARPE-19 cells. Thus, integrin α(2) expression levels directly correlated with the degree of cell alignment in all examined RPE cell types. Specific integrin subunit α(2)-mediated matrix binding was verified by preincubation with an α(2)-function-blocking antibody, which impaired cell adhesion and alignment to varying degrees in primary and SV40-RPE cells. Since native matrices supported extended and directed primary RPE cell growth, optimizing the matrix production procedure may in the future yield nanostructured collagen matrices serving as transferable cell sheet carriers.

Persistent directional cell migration requires ion transport proteins as direction sensors and membrane potential differences in order to maintain directedness

BACKGROUND

Ion transport proteins generate small electric fields that can induce directional cell motility; however, little is known about their mechanisms that lead to directedness. We investigated Na, K-ATPase (NaKA) and Na+/H+ exchanger isoforms (NHE1 and 3) in SaOS-2 and Calvarial osteoblasts, which present anode- and cathode- directed motility, during electrotaxis.

RESULTS

Significant colocalizations of NaKA with vinculin and pNHE3 with ß-actin were observed to occur at the leading edges of cells. The directedness were attenuated when NaKA or NHE3 was inhibited, confirming their implication in directional sensing. Depending on the perceived direction, a divergent regulation in PIP2 levels as a function of NHE3 and NaKA levels was observed, suggesting that PIP2 may act as a spatiotemporal regulator of the cell membrane during electrotaxis. Moreover, at the same places where pNHE3 accumulates, bubble-shaped H+ clouds were observed, suggesting a physio-mechanical role for NHE3. The cell membrane becomes hyperpolarized at the front and depolarized at the back, which confirms NaKA activity at the leading edge.

CONCLUSION

We suggest a novel role for both NaKA and NHE3 that extends beyond ion translocation and conclude that they can act as directional sensors and Vmem as a regulatory cue which maintain the persistent direction in electrotaxis.

Oral administration of rotenone using a gavage and image analysis of alpha-synuclein inclusions in the enteric nervous system

In Parkinson's disease (PD) patients, the associated pathology follows a characteristic pattern involving inter alia the enteric nervous system (ENS) (1,2), the olfactory bulb (OB), the dorsal motor nucleus of the vagus (DMV)(3), the intermediolateral nucleus of the spinal cord (4) and the substantia nigra, providing the basis for the neuropathological staging of the disease(4,5). The ENS and the OB are the most exposed nervous structures and the first ones to be affected. Interestingly, PD has been related to pesticide exposure(6-8). Here we show in detail two methods used in our previous study (9). In order to analyze the effects of rotenone acting locally on the ENS, we administered rotenone using a gavage to one-year old C57/BL6 mice. Rotenone is a widely used pesticide that strongly inhibits mitochondrial Complex I (10). It is highly lipophylic and poorly absorbed in the gastrointestinal tract (11). Our results showed that the administration of 5 mg/kg of rotenone did not inhibit mitochondrial Complex I activity in the muscle or the brain. Thus, suggesting that using our administration method rotenone did not cross the hepatoportal system and was acting solely on the ENS. Here we show a method to administer pesticides using a gavage and the image analysis protocol used to analyze the effects of the pesticide in alpha-synuclein accumulation in the ENS. The first part shows a method that allows intragastric administration of pesticides (rotenone) at a desired precise concentration. The second method shows a semi-automatic image analysis protocol to analyze alpha-synuclein accumulation in the ENS using an image analysis software.

Ion imaging during axolotl tail regeneration in vivo

Several studies have reported that endogenous ion currents are involved in a wide range of biological processes from single cell and tissue behavior to regeneration. Various methods are used to assess intracellular and local ion dynamics in biological systems, e.g., patch clamping and vibrating probes. Here, we introduce an approach to detect ion kinetics in vivo using a noninvasive method that can electrophysiologically characterize an entire experimental tissue region or organism. Ion-specific vital dyes have been successfully used for live imaging of intracellular ion dynamics in vitro. Here, we demonstrate that cellular pH, cell membrane potential, calcium, sodium and potassium can be monitored in vivo during tail regeneration in the axolotl (Ambystoma mexicanum) using ion-specific vital dyes. Thus, we suggest that ion-specific vital dyes can be a powerful tool to obtain electrophysiological data during crucial biological events in vivo.

Alignment and cell-matrix interactions of human corneal endothelial cells on nanostructured collagen type I matrices

PURPOSE

To use nanoscopically defined, two-dimensional matrices assembled from aligned collagen type I fibrils as a sheet substratum for in vitro cultivation of human corneal endothelial cells (HCECs). To assess the effect of matrix architecture on HCEC morphology and to characterize integrin-mediated HCEC-matrix interaction.

METHODS

Cell alignment and cell-matrix interactions of primary HCECs and three different immortalized HCEC populations on native and UV-cross-linked collagen type I matrices were examined by time-lapse microscopy. Specific integrin α(2)β(1) binding to the collagen matrix was demonstrated using a function-blocking α(2) antibody. Integrin α(2) subunit expression levels of the four HCEC populations were analyzed by Western blot analysis.

RESULTS

All HCEC populations aligned along the oriented collagen fibrils. Primary HCECs and, to a lesser extent, the other tested HCEC populations exerted high traction forces, leading to progressive matrix destruction. Cross-linking of the collagen matrices considerably increased matrix stability. Integrin subunit α(2) expression levels of the four cell types correlated with the degree of cell alignment and exertion of traction forces. In turn, blocking integrin subunit α(2) reduced cell alignment and prevented matrix destruction.

CONCLUSIONS

HCECs align directionally along parallel arrays of collagen type I fibrils. The interactions of HCECs with collagen type I are primarily mediated by integrin α(2)β(1). Integrin subunit α(2) levels correlate with matrix contraction and subsequent destruction. Sustained cultivation of HCECs on ultrathin collagen matrices thus requires matrix cross-linking and moderate integrin α(2)β(1) expression levels.

Neurodegenerative diseases of the retina and potential for protection and recovery

Recent advances in our understanding of the mechanisms in the cascade of events resulting in retinal cell death in ocular pathologies like glaucoma, diabetic retinopathy and age-related macular degeneration led to the common descriptive term of neurodegenerative diseases of the retina. The final common pathophysiologic pathway of these diseases includes a particular form of metabolic stress, resulting in an insufficient supply of nutrients to the respective target structures (optic nerve head, retina). During metabolic stress, glutamate is released initiating the death of neurones containing ionotropic glutamate (N-methyl-D-aspartat, NMDA) receptors present on ganglion cells and a specific type of amacrine cells. Experimental studies demonstrate that several drugs reduce or prevent the death of retinal neurones deficient of nutrients. These agents generally block NMDA receptors to prevent the action of glutamate or halt the subsequent pathophysiologic cycle resulting in cell death. The major causes for cell death following activation of NMDA receptors are the influx of calcium and sodium into cells, the generation of free radicals linked to the formation of advanced glycation endproducts (AGEs) and/or advanced lipoxidation endproducts (ALEs) as well as defects in the mitochondrial respiratory chain. Substances preventing these cytotoxic events are considered to be potentially neuroprotective.

Progression of Parkinson's disease pathology is reproduced by intragastric administration of rotenone in mice

In patients with Parkinson's disease (PD), the associated pathology follows a characteristic pattern involving inter alia the enteric nervous system (ENS), the dorsal motor nucleus of the vagus (DMV), the intermediolateral nucleus of the spinal cord and the substantia nigra, providing the basis for the neuropathological staging of the disease. Here we report that intragastrically administered rotenone, a commonly used pesticide that inhibits Complex I of the mitochondrial respiratory chain, is able to reproduce PD pathological staging as found in patients. Our results show that low doses of chronically and intragastrically administered rotenone induce alpha-synuclein accumulation in all the above-mentioned nervous system structures of wild-type mice. Moreover, we also observed inflammation and alpha-synuclein phosphorylation in the ENS and DMV. HPLC analysis showed no rotenone levels in the systemic blood or the central nervous system (detection limit [rotenone]<20 nM) and mitochondrial Complex I measurements showed no systemic Complex I inhibition after 1.5 months of treatment. These alterations are sequential, appearing only in synaptically connected nervous structures, treatment time-dependent and accompanied by inflammatory signs and motor dysfunctions. These results strongly suggest that the local effect of pesticides on the ENS might be sufficient to induce PD-like progression and to reproduce the neuroanatomical and neurochemical features of PD staging. It provides new insight into how environmental factors could trigger PD and suggests a transsynaptic mechanism by which PD might spread throughout the central nervous system.

Biological relevance of ion energy in performance of human endothelial cells on ion-implanted flexible polyurethane surfaces

To improve the biocompatibility of polyurethane (PUR), we modified the surface by irradiation with different ions (Carbon; C, Oxygen; O, Nitrogen; N, or Argon; Ar) at 0.3-50 keV energy and doses of 1,00E+13 - 1,00E+15 ions/cm(2). The effects of ion implantation using different ion energies and densities were observed on adhesion, proliferation, and viability of human umbilical vein endothelial cells (HUVECs). The long-term in vitro stability of ion-implanted PUR was also investigated. Ion irradiation moderately affected the surface roughness (R(a)), but strongly enhanced the work of adhesion (W(a)). Cell adhesion was markedly improved on O-, N-, and Ar-, but not on C-implanted PUR surfaces. Medium ion energies and lower ion doses produced the best HUVEC attachment and proliferation, indicating the importance of choosing the proper range of energy applied during ion irradiation. In addition, apoptosis rates were significantly reduced when compared with unmodified PUR (uPUR). N implantation significantly protected the surface, although C implantation led to stronger surface erosions than on uPUR. In total, ion implantation on flexible PUR surfaces strongly improved the material surface characteristics and biocompatibility. Electron beam ion implantation within an appropriate energy window is thus a key to improving flexible PUR surfaces for clinical use to support endothelial cell performance. Thus, it can contribute to designing small-diameter grafts, which are in great demand, towards vascular tissue engineering applications.

Electromagnetic effects - From cell biology to medicine

In this review we compile and discuss the published plethora of cell biological effects which are ascribed to electric fields (EF), magnetic fields (MF) and electromagnetic fields (EMF). In recent years, a change in paradigm took place concerning the endogenously produced static EF of cells and tissues. Here, modern molecular biology could link the action of ion transporters and ion channels to the "electric" action of cells and tissues. Also, sensing of these mainly EF could be demonstrated in studies of cell migration and wound healing. The triggers exerted by ion concentrations and concomitant electric field gradients have been traced along signaling cascades till gene expression changes in the nucleus. Far more enigmatic is the way of action of static MF which come in most cases from outside (e.g. earth magnetic field). All systems in an organism from the molecular to the organ level are more or less in motion. Thus, in living tissue we mostly find alternating fields as well as combination of EF and MF normally in the range of extremely low-frequency EMF. Because a bewildering array of model systems and clinical devices exits in the EMF field we concentrate on cell biological findings and look for basic principles in the EF, MF and EMF action. As an outlook for future research topics, this review tries to link areas of EF, MF and EMF research to thermodynamics and quantum physics, approaches that will produce novel insights into cell biology.

Effects of advanced glycation end products-inductor glyoxal and hydrogen peroxide as oxidative stress factors on rat retinal organ cultures and neuroprotection by UK-14,304

Retinal ganglion cell degeneration is supposed to be mediated by reactive oxygen species (ROS) and advanced glycation end products (AGEs). The alpha2-adrenergic agonist, 5-bromo-N-(4,5-dihydro-1H-imidazol-2-yl)-6-quinoxalinamine (brimonidine; UK-14,304), is said to exert a neuroprotective effect. To investigate these mechanisms in detail, we exposed rat whole mounts to glyoxal or H(2)O(2) and treated them with either UK-14,304 alone or additionally with the phosphatidylinositide 3 kinase (PI3) kinase inhibitor, 2-(4-Morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (Ly 294002). The accumulation of Nepsilon-[carboxymethyl] lysine (CML) was assessed immunohistochemically and changes in intracellular pH (pHi), mitochondrial transmembrane potential (MTMP) and ROS production in cell bodies of multipolar ganglion cell layer were studied by intravital fluorescence microscopy and confocal laser scanning microscopy. Ultrastructural changes in mitochondria of multipolar ganglion cell layer cell bodies were determined by transmission electron microscopy. We found that glyoxal and H(2)O(2) increased accumulation of CML-modified proteins and ROS production and decreased pHi and MTMP in cell bodies of multipolar ganglion cell layer. UK-14,304 could prevent production of ROS, accumulation of CML-modified proteins, ameliorate acidification, preserve MTMP and attenuate ultrastructural damages of ganglion cell mitochondria. Ly 294002 reversed the UK-14,304-mediated attenuation of CML and ROS production. We conclude that the protective effects of UK-14,304 seem partly to be mediated by PI3 kinase-dependent pathways.

Two clonal cell lines of immortalized human corneal endothelial cells show either differentiated or precursor cell characteristics

Access to primary human corneal endothelial cells (HCEC) is limited and donor-derived differences between cultures exacerbate the issue of data reproducibility, whereas cell lines can provide sufficient numbers of homogenous cells for multiple experiments. An immortalized HCEC population was adapted to serum-free culture medium and repeated cloning was performed. Clonally grown cells were propagated under serum-free conditions and growth curves were recorded. Cells were characterized immunocytochemically for junctional proteins, collagens, Na,K-ATPase and HCEC-specific 9.3.E-antigen. Ultrastructure was monitored by scanning and transmission electron microscopy. Two clonal cell lines, HCEC-B4G12 and HCEC-H9C1, could be isolated and expanded, which differed morphologically: B4G12 cells were polygonal, strongly adherent and formed a strict monolayer, H9C1 cells were less adherent and formed floating spheres. The generation time of B4G12 cells was 62.26 +/- 14.5 h and that of H9C1 cells 44.05 +/- 5.05 h. Scanning electron microscopy revealed that B4G12 cells had a smooth cell surface, while H9C1 cells had numerous thin filopodia. Both cell lines expressed ZO-1 and occludin adequately, and little but well detectable amounts of connexin-43. Expression of HCEC-specific 9.3.E-antigen was found commensurately in both cell lines, while expression of Na,K-ATPase alpha1 was higher in H9C1 cells than in B4G12 cells. B4G12 cells expressed collagen IV abundantly and almost no collagen III, while H9C1 cells expressed both collagens at reasonable amounts. It is concluded that the clonal cell line B4G12 represents an ideal model of differentiated HCEC, while H9C1 may reflect features of developing or transitional HCEC.

Effects of electromagnetic fields on cells: physiological and therapeutical approaches and molecular mechanisms of interaction. A review

This review concentrates on findings described in the recent literature on the response of cells and tissues to electromagnetic fields (EMF). Models of the causal interaction between different forms of EMF and ions or biomolecules of the cell will be presented together with our own results in cell surface recognition. Naturally occurring electric fields are not only important for cell-surface interactions but are also pivotal for the normal development of the organism and its physiological functions. A further goal of this review is to bridge the gap between recent cell biological studies (which, indeed, show new data of EMF actions) and aspects of EMF-based therapy, e.g., in wounds and bone fractures.

Studies on Stress-Induced Changes at the Subcellular Level by Raman Microspectroscopic Mapping

Raman microspectroscopic mapping enables one to study the chemical composition and molecular structure of subcellular components in individual cells without the need for labeling. Lung fibroblast cells were prepared under normal conditions and under stress, which was induced by 24 h of exposure to glyoxal. Raman microspectroscopic maps were recorded from fixed cells with 785-nm excitation and with 1-microm step width. Cluster analysis was applied to generate pseudocolor images of the cell morphology. Raman maps revealed that the cell nucleus shrinks in stressed cells, called pyknosis, which refers to an early stage of apoptosis. The intensity of nucleic acid bands decreased in cluster-averaged Raman spectra of the nucleus and cytoplasm, which is consistent with degradation and conformational changes of DNA and RNA. During a later stage of apoptosis, Raman maps indicate a rounding of cells, a further intensity decrease of nucleic acids bands, fragmentation of the nucleus, disappearance of lipid bodies, and formation of blisters at the cell surface. Whereas the peripheral membrane of the undisturbed cell is composed of lipids and cholesterol, the blisters have a higher protein content with nucleic acids incorporated. The results demonstrate that Raman spectroscopic mapping might become a powerful tool in cell biology for single cell analysis.