Dual specificity kinase DYRK3 regulates cell migration by influencing the stability of protrusions

Plasma membrane-associated platforms (PMAPs) form at specific sites of plasma membrane by scaffolds including ERC1 and Liprin-α1. We identify a mechanism regulating PMAPs assembly, with consequences on motility/invasion. Silencing Ser/Thr kinase DYRK3 in invasive breast cancer cells inhibits their motility and invasive capacity. Similar effects on motility were observed by increasing DYRK3 levels, while kinase-dead DYRK3 had limited effects. DYRK3 overexpression inhibits PMAPs formation and has negative effects on stability of lamellipodia and adhesions in migrating cells. Liprin-α1 depletion results in unstable lamellipodia and impaired cell motility. DYRK3 causes increased Liprin-α1 phosphorylation. Increasing levels of Liprin-α1 rescue the inhibitory effects of DYRK3 on cell spreading, suggesting that an equilibrium between Liprin-α1 and DYRK3 levels is required for lamellipodia stability and tumor cell motility. Our results show that DYRK3 is relevant to tumor cell motility, and identify a PMAP target of the kinase, highlighting a new mechanism regulating cell edge dynamics.

Interfering with the ERC1-LL5β interaction disrupts plasma membrane-Associated platforms and affects tumor cell motility

Cell migration requires a complex array of molecular events to promote protrusion at the front of motile cells. The scaffold protein LL5β interacts with the scaffold ERC1, and recruits it at plasma membrane-associated platforms that form at the front of migrating tumor cells. LL5 and ERC1 proteins support protrusion during migration as shown by the finding that depletion of either endogenous protein impairs tumor cell motility and invasion. In this study we have tested the hypothesis that interfering with the interaction between LL5β and ERC1 may be used to interfere with the function of the endogenous proteins to inhibit tumor cell migration. For this, we identified ERC1(270-370) and LL5β(381-510) as minimal fragments required for the direct interaction between the two proteins. The biochemical characterization demonstrated that the specific regions of the two proteins, including predicted intrinsically disordered regions, are implicated in a reversible, high affinity direct heterotypic interaction. NMR spectroscopy further confirmed the disordered nature of the two fragments and also support the occurrence of interaction between them. We tested if the LL5β protein fragment interferes with the formation of the complex between the two full-length proteins. Coimmunoprecipitation experiments showed that LL5β(381-510) hampers the formation of the complex in cells. Moreover, expression of either fragment is able to specifically delocalize endogenous ERC1 from the edge of migrating MDA-MB-231 tumor cells. Coimmunoprecipitation experiments show that the ERC1-binding fragment of LL5β interacts with endogenous ERC1 and interferes with the binding of endogenous ERC1 to full length LL5β. Expression of LL5β(381-510) affects tumor cell motility with a reduction in the density of invadopodia and inhibits transwell invasion. These results provide a proof of principle that interfering with heterotypic intermolecular interactions between components of plasma membrane-associated platforms forming at the front of tumor cells may represent a new approach to inhibit cell invasion.

Liquid-Liquid Phase Separation at the Plasma Membrane-Cytosol Interface: Common Players in Adhesion, Motility, and Synaptic Function

Networks of scaffold proteins and enzymes assemble at the interface between the cytosol and specific sites of the plasma membrane, where these networks guide distinct cellular functions. Some of these plasma membrane-associated platforms (PMAPs) include shared core components that are able to establish specific protein-protein interactions, to produce distinct supramolecular assemblies regulating dynamic processes as diverse as cell adhesion and motility, or the formation and function of neuronal synapses. How cells organize such dynamic networks is still an open question. In this review we introduce molecular networks assembling at the edge of migrating cells, and at pre- and postsynaptic sites, which share molecular players that can drive the assembly of biomolecular condensates. Very recent experimental evidence has highlighted the emerging role of some of these multidomain/scaffold proteins belonging to the GIT, liprin-α and ELKS/ERC families as drivers of liquid-liquid phase separation (LLPS). The data point to an important role of LLPS: (i) in the formation of PMAPs at the edge of migrating cells, where LLPS appears to be involved in promoting protrusion and the turnover of integrin-mediated adhesions, to allow forward cell translocation; (ii) in the assembly of the presynaptic active zone and of the postsynaptic density deputed to the release and reception of neurotransmitter signals, respectively. The recent results indicate that LLPS at cytosol-membrane interfaces is suitable not only for the regulation of active cellular processes, but also for the continuous spatial rearrangements of the molecular interactions involved in these dynamic processes.

Natural hydrogels R&D process: technical and regulatory aspects for industrial implementation

Since hydrogel therapies have been introduced into clinic treatment procedures, the biomedical industry has to face the technology transfer and the scale-up of the processes. This will be key in the roadmap of the new technology implementation. Transfer technology and scale-up are already known for some applications but other applications, such as 3D printing, are still challenging. Decellularized tissues offer a lot of advantages when compared to other natural gels, for example they display enhanced biological properties, due to their ability to preserve natural molecules. For this reason, even though their use as a source for bioinks represents a challenge for the scale-up process, it is very important to consider the advantages that originate with overcoming this challenge. Therefore, many aspects that influence the scaling of the industrial process should be considered, like the addition of drugs or cells to the hydrogel, also, the gelling process is important to determine the chemical and physical parameters that must be controlled in order to guarantee a successful process. Legal aspects are also crucial when carrying out the scale-up of the process since they determine the industrial implementation success from the regulatory point of view. In this context, the new law Regulation (EU) 2017/745 on biomedical devices will be considered. This review summarizes the different aspects, including the legal ones, that should be considered when scaling up hydrogels of natural origin, in order to balance these different aspects and to optimize the costs in terms of raw materials and engine.

Polylysine Enriched Matrices: A Promising Approach for Vascular Grafts

Cardiovascular diseases represent the leading cause of death in developed countries. Modern surgical methods show poor efficiency in the substitution of small-diameter arteries (<6 mm). Due to the difference in mechanical properties between the native artery and the substitute, the behavior of the vessel wall is a major cause of inefficient substitutions. The use of decellularized scaffolds has shown optimal prospects in different applications for regenerative medicine. The purpose of this work was to obtain polylysine-enriched vascular substitutes, derived from decellularized porcine femoral and carotid arteries. Polylysine acts as a matrix cross-linker, increasing the mechanical resistance of the scaffold with respect to decellularized vessels, without altering the native biocompatibility and hemocompatibility properties. The biological characterization showed an excellent biocompatibility, while mechanical tests displayed that the Young's modulus of the polylysine-enriched matrix was comparable to native vessel. Burst pressure test demonstrated strengthening of the polylysine-enriched matrix, which can resist to higher pressures with respect to native vessel. Mechanical analyses also show that polylysine-enriched vessels presented minimal degradation compared to native. Concerning hemocompatibility, the performed analyses show that polylysine-enriched matrices increase coagulation time, with respect to commercial Dacron vascular substitutes. Based on these findings, polylysine-enriched decellularized vessels resulted in a promising approach for vascular substitution.

Overview of natural hydrogels for regenerative medicine applications

Hydrogels from different materials can be used in biomedical field as an innovative approach in regenerative medicine. Depending on the origin source, hydrogels can be synthetized through chemical and physical methods. Hydrogel can be characterized through several physical parameters, such as size, elastic modulus, swelling and degradation rate. Lately, research is focused on hydrogels derived from biologic materials. These hydrogels can be derived from protein polymers, such as collage, elastin, and polysaccharide polymers like glycosaminoglycans or alginate among others. Introduction of decellularized tissues into hydrogels synthesis displays several advantages compared to natural or synthetic based hydrogels. Preservation of natural molecules such as growth factors, glycans, bioactive cryptic peptides and natural proteins can promote cell growth, function, differentiation, angiogenesis, anti-angiogenesis, antimicrobial effects, and chemotactic effects. Versatility of hydrogels make possible multiple applications and combinations with several molecules on order to obtain the adequate characteristic for each scope. In this context, a lot of molecules such as cross link agents, drugs, grow factors or cells can be used. This review focuses on the recent progress of hydrogels synthesis and applications in order to classify the most recent and relevant matters in biomedical field.

Scanning X-ray microdiffraction of decellularized pericardium tissue at increasing glucose concentration

Blood glucose supplies energy to cells and is critical for the human brain. Glycation of collagen, the nonenzymatic formation of glucose-bridges, relates to diseases of aging populations and diabetics. This chemical reaction, together with its biomechanical effects, has been well studied employing animal models. However, the direct impact of glycation on collagen nano-structure is largely overlooked, and there is a lack of ex vivo model systems. Here, we present the impact of glucose on collagen nanostructure in a model system based on abundantly available connective tissue of farm animals. By combining ex vivo small and wide-angle X-ray scattering (SAXS/WAXS) imaging, we characterize intra- and inter-molecular parameters of collagen in decellularized bovine pericardium with picometer precision. We observe three distinct regimes according to glucose concentration. Such a study opens new avenues for inspecting the effects of diabetes mellitus on connective tissues and the influence of therapies on the resulting secondary disorders.

X-ray scanning microscopies of microcalcifications in abdominal aortic and popliteal artery aneurysms

Abdominal aortic and popliteal artery aneurysms are vascular diseases which show massive degeneration, weakening of the vascular wall and loss of the vascular tissue functionality. They are driven by inflammatory, hemodynamical factors and biological alterations that may lead, in the case of an abdominal aortic aneurysm, to sudden and dangerous ruptures of the arteries. Here, human aortic and popliteal aneurysm tissues were obtained during surgical repair, and studied by synchrotron radiation X-ray scanning microdiffraction and small-angle scattering, to investigate the microcalcifications present in the tissues. Data collected during the experiments were transformed into quantitative microscopy images through the combination of statistical approaches and crystallographic methods. As a result of this multi-step analysis, microcalcifications, which are markers of the pathology, were classified in terms of chemical and structural content. This analysis helped to identify the presence of nanocrystalline hy-droxy-apatite and microcrystalline cholesterol, embedded in myofilament, and elastin-containing tissue with low collagen content in predominantly nanocrystalline areas. The generality of the approach allows it to be transferred to other types of tissue and other pathologies affected by microcalcifications, such as thyroid carcinoma, breast cancer, testicular microli-thia-sis or glioblastoma.

Relevance of inflammation and matrix remodeling in abdominal aortic aneurysm (AAA) and popliteal artery aneurysm (PAA) progression

Aneurysm is a multifactorial degenerative disease characterized by focal dilatation of blood vessels. Although abdominal aortic (AAA) and popliteal aneurysms (PAA) are the most common dilatative vascular diseases and share some features, a comparison between the different anatomical sites and the relative pathophysiological differences has not been established. In order to gain deeper insights to AAA and PAA, we have characterized the role of matrix remodelling, vascular cells phenotype depletion and the inflammatory process in both diseases. Results show a more extensive presence of T-cell, B-cell and monocyte-macrophage infiltration in AAA with respect to PAA. Concurring with this aspect, IL-6, IL-8 and MCP-1 are 10-fold increased in AAA. Moreover, MMP-9, and metalloproteinase inhibitor 3 (TIMP3) resulted up-regulated in AAA tissues. Regarding the catalytic activity, which is tightly related to the oxidative stress, we found an up-regulation of superoxide dismutase [Mn] mitochondrial (SODM), glutathione peroxidase 3 (GPX3) and peroxiredoxin-1 (PRDX1). Histological analyses clearly showed a massive elastin fragmentation in AAA. This may enhance the inflammatory response, which has a prevalent role in AAA, while PAA is mainly guided by a loss of the contractile phenotype. These findings suggest insight in these potentially devastating diseases in term of their progression, aiming to identify potential specific markers respectively for AAA and PAA treatment.

Endothelial MMP-9 drives the inflammatory response in abdominal aortic aneurysm (AAA)

Progression of abdominal aortic aneurysm (AAA) is typified by chronic inflammation and extracellular matrix (ECM) degradation of the aortic wall. Vascular inflammation involves complex interactions among inflammatory cells, endothelial cells (ECs), vascular smooth muscle cells (vSMCs), and ECM. Although vascular endothelium and medial neoangiogenesis play a key role in AAA, the molecular mechanisms underlying their involvement are only partially understood. In AAA biopsies, we found increased MMP-9, IL-6, and monocyte chemoattractant protein-1 (MCP-1), which correlated with massive medial neo-angiogenesis (C4d positive staining). In this study, we developed an in vitro model in order to characterize the role of endothelial matrix metalloproteinase-9 (e-MMP-9) as a potential trigger of medial disruption and in the inflammatory response bridging between ECs and vSMC. Lentiviral-mediated silencing of e-MMP-9 through RNA interference inhibited TNF-alpha-mediated activation of NF-κB in EA.hy926 human endothelial cells. In addition, EA.hy926 cells void of MMP-9 failed to migrate in a 3D matrix. Moreover, silenced EA.hy926 affected vSMC behavior in terms of matrix remodeling. In fact, also MMP-9 in vSMC resulted inhibited when endothelial MMP-9 was suppressed.

Decellularized biological matrices: an interesting approach for cardiovascular tissue repair and regeneration

The repair and replacement of blood vessels is one of the most challenging topics for biomedical research. Autologous vessels are preferred as graft materials, but they still have many issues to overcome: for instance, they need multiple surgical procedures and often patients may not have healthy and surgically valuable arteries useful as an autograft. A tissue-engineering approach is widely desirable to generate biological vascular prostheses. Recently, decellularization of native tissue has gained significant attention in the biomedical research field. This method is used to obtain biological scaffolds that are expected to maintain the complex three-dimensional structure of the extracellular matrix, preserving the biomechanical properties of the native tissues. The decellularizing methods and the biomechanical characteristics of these products are presented in this review. Decellularization of biological matrices induces the loss of major histocompatibility complex (MHC), which is expected to promote an immunological response by the host. All the studies showed that decellularized biomaterials possess adequate properties for xenografting. Concerning their mechanical properties, several studies have demonstrated that, although chemical decellularization methods do not affect the scaffolds' mechanical properties, these materials can be modified through different treatments in order to provide the desired mechanical characteristics, depending on the specific application. A short overview of legislative issues concerning the use of decellularized substitutes and future perspectives in surgical applications is also presented. Copyright © 2015 John Wiley & Sons, Ltd.

An optimized table-top small-angle X-ray scattering set-up for the nanoscale structural analysis of soft matter

The paper shows how a table top superbright microfocus laboratory X-ray source and an innovative restoring-data algorithm, used in combination, allow to analyze the super molecular structure of soft matter by means of Small Angle X-ray Scattering ex-situ experiments. The proposed theoretical approach is aimed to restore diffraction features from SAXS profiles collected from low scattering biomaterials or soft tissues, and therefore to deal with extremely noisy diffraction SAXS profiles/maps. As biological test cases we inspected: i) residues of exosomes' drops from healthy epithelial colon cell line and colorectal cancer cells; ii) collagen/human elastin artificial scaffolds developed for vascular tissue engineering applications; iii) apoferritin protein in solution. Our results show how this combination can provide morphological/structural nanoscale information to characterize new artificial biomaterials and/or to get insight into the transition between healthy and pathological tissues during the progression of a disease, or to morphologically characterize nanoscale proteins, based on SAXS data collected in a room-sized laboratory.

Postural disorders in conservatory students: the Diesis project

Prolonged and incorrect postures are one of the main risk factors for the development of musculoskeletal pathologies. The aims of this study were to study the prevalence of incorrect postures among conservatory students; to identify if the use of an asymmetric instrument represents a risk factor for developing postural disorders; and to investigate whether a correlation exists between years of study, physical activity, and prevalence of postural disorders.

METHODS

The subjects were recruited among students of the Giuseppe Verdi Conservatory of Milano. All musical instruments were investigated and classified as asymmetric and symmetrical. The observed student posture was classified without instrument as "correct posture" or "postural disorder" and with an with instrument as "optimal posture" or "non-optimal posture." While playing, the postural disorder was classified as "unchanged" or "increased." The data were analyzed with chi-square and linear regression methods.

RESULTS

Of the 148 conservatory students entered into the study, 66.2% had a postural disorder; 73.4% had a non-optimal posture, and playing an asymmetric instrument was the only variable associated (p=0.01). While playing, the postural disorder was increased in 59.2%; playing an asymmetric instrument (p=0.01) and years of practice (p=0.007) were the significantly associated variables.

CONCLUSIONS

To play an asymmetric instrument exposes musicians to an increased risk of non-optimal postures and to a worsened postural disorder when present. Considering that the years of practice have an additional negative impact on postural disorders, further studies are needed to clarify the role of non-optimal postures in the development of musculoskeletal complaints among students and professional musicians.

The effect of mechanical strain on soft (cardiovascular) and hard (bone) tissues: common pathways for different biological outcomes

Mechanical stress plays a pivotal role in developing and maintaining tissues functionalities. Cells are constantly subjected to strain and compressive forces that are sensed by specialized membrane mechanosensors and converted in biochemical signals able to differently influence cellular behavior in terms of surviving, differentiation and extracellular matrix remodeling. This review focuses on the effects of mechanical strain on soft and hard tissues. Unexpectedly, different cells share almost the same membrane mechanosensors and the relative intracellular pathways, but to ultimately obtain very different biological effects. The events occurring in cardiovascular and bone tissues are treated in details, showing that integrins, cadherins, growth factor receptors and ions channels specifically expressed in the different tissues are the major actors of the sight. However, MAPkinases and RhoGTPases are mainly involved in the biochemical intracellular signaling directed to nuclear modifications.

Corkscrew retinal vessels in neurofibromatosis type 1: report of 12 cases

AIM

To describe a distinctive spectrum of retinal microvascular abnormalities in 12 patients with neurofibromatosis type 1 (NF-1).

METHODS

This is an observational prospective study of the ocular fundus evaluated by direct ophthalmoscopy with or without fluorescein angiography, to investigate retinal microvascular abnormalities in 32 patients with NF-1 and in 30 control subjects. The evaluation included a complete general and neurological physical examination and in some cases computed tomography, magnetic resonance imaging with gadolinium-DTPA, or both.

RESULTS

The occurrence of a distinctive spectrum of retinal microvascular abnormalities is described in 12 patients with NF-1 (37.5%). At the lower end of the spectrum, present in 10 patients, the anomaly consisted of minuscule second or third order tortuous venules, which were called "corkscrew retinal vessels." These were usually isolated but in a few cases multiple. They flow towards the superior or inferior temporal veins. They had a length of one to two disc diameters. They ended either in a minute tuft or vanished on the retinal surface. The upper end of the spectrum was seen in only two patients. One of them had an exceptionally large venous anastomosis on the nasal retina and the other had an arteriovenous malformation extending over one retinal quadrant. None of the patients in the control group had such retinal microvascular abnormalities.

CONCLUSION

The "corkscrew" retinal vessels described in this report constitute a broad spectrum of microvascular markers in NF-1 patients.

Spontaneous regression of optic gliomas: thirteen cases documented by serial neuroimaging

OBJECTIVE

To demonstrate spontaneous regression of large, clinically symptomatic optic pathway gliomas in patients with and without neurofibromatosis type 1 (NF-1).

METHODS

Patient cases were collected through surveys at 2 consecutive annual meetings of the North American Neuro-Ophthalmology Society (NANOS) and through requests on the NANOSNET Internet listserv. Serial documentation of tumor signal and size, using magnetic resonance imaging in 11 patients and computed tomography in 2 patients, was used to evaluate clinically symptomatic optic pathway gliomas. All tumors met radiologic criteria for the diagnosis of glioma and 4 patients had biopsy confirmation of their tumors. In 3 patients, some attempt at therapy had been made many years before regression occurred. In one of these, radiation treatment had been given 19 years before tumor regression, while in another, chemotherapy had been administered 5 years before signal changes in the tumor. In the third patient, minimal surgical debulking was performed 1 year before the tumor began to shrink.

RESULTS

Spontaneous tumor shrinkage was noted in 12 patients. Eight patients did not have NF-1. In an additional patient without NF-1, a signal change within the tumor without associated shrinkage was detected. Tumor regression was associated with improvement in visual function in 10 of 13 patients, stability of function in 1, and deterioration in 2.

CONCLUSIONS

Large, clinically symptomatic optic gliomas may undergo spontaneous regression. Regression was seen in patients with and without NF-1. Regression may manifest either as an overall shrinkage in tumor size, or as a signal change on magnetic resonance imaging. A variable degree of improvement in visual function may accompany regression. The possibility of spontaneous regression of an optic glioma should be considered in the planning of treatment of patients with these tumors.

Optociliary veins in optic nerve sheath meningioma. Indocyanine green videoangiography findings

OBJECTIVE

To report the indocyanine green videoangiography (ICG-V) characteristics of optociliary veins (OV) in optic nerve sheath meningioma (ONSM).

DESIGN

Case series.

PARTICIPANTS

Four eyes (patients) with OV and ONSM were examined.

INTERVENTION

Indocyanine green videoangiography and intravenous fluorescein angiography (IVFA) were prospectively performed.

MAIN OUTCOME MEASURES

The course of OV in ONSM cases was observed with ICG-V and IVFA.

RESULTS

On ICG-V, the course of OV was followed from their origin at small tributaries of the central retinal vein, their junction with choroidal veins, and finally to their drainage in the vortex venous system. The authors found an inverse relationship between the degree of optic disc edema and the development and ease of visualization of the optociliary veins and their draining course through the choroidal circulation. The mean time from the injection of indocyanine green to the visualization of OV's draining choroidal vessels was 35.4 seconds (range, 25.4-50 seconds). Intravenous fluorescein angiography allowed visualization of OV only at the margins of the optic disc in all cases.

CONCLUSION

Indocyanine green videoangiography provides important and new information in cases with OV and ONSM that is not obtained with IVFA. Such information may provide important knowledge regarding the hemodynamics of the choroidal circulation in normal and pathologic states.

Relationship between rheumatoid factor and the immune response against hepatitis C virus in essential mixed cryoglobulinemia

OBJECTIVE

The authors examine the relationship between the presence of hepatitis C virus (HCV) and anti-HCV antibodies, rheumatoid factor (RF) activity, the level of complement, and the cryocrit in the sera of patients affected by essential mixed cryoglobulinemia (EMC). In addition, the authors evaluate the circulating B-CD5 positive lymphocytes, believed to be RF producers in the blood of EMC patients.

METHODS

Clinical and laboratory data on 219 cases of EMC were collected from five centers of the GISC (Italian Group for the Study of Cryoglobulinemias). Statistical analyses of these data were carried out with the aim of evidentiating significant relationships, in order to shed light on the mechanism of cryoprecipitation.

RESULTS

The cryocrit was higher in anti-HCV negative and in HCV-RNA positive sera. The titers of RF activity were significantly higher in anti-HCV negative sera. A linear correlation between RF activity and the cryocrit was observed for HCV-RNA positive cases (r = 0.416), this correlation being highest in the patients who were HCV-RNA positive and anti-HCV negative (0.709). Type III EMC were more reactive than type II against the non-structural antigens of HCV, particularly 5-1-1 and C-22. There were more circulating B lymphocytes sharing membrane antigen CD5 in EMC than in the blood of normals or patients with HCV-related chronic hepatitis. Levels of circulating B-CD5 correlated with serum RF activity (r = 0.677), especially in sera from anti-C-100 negative patients (p = 0.991).

CONCLUSION

The data strongly suggest that the level of the cryoprecipitate is a function of both the HCV-RNA in the serum and the RF activity. Antibody specificity against HCV probably influences the density of the cryoprecipitate.

Cutaneous findings in a new syndrome of autosomal recessive ectodermal dysplasia with corkscrew hairs

BACKGROUND

The association of hair shaft abnormalities with the phenotypic findings of a new, distinct form of an autosomal recessive syndrome of ectodermal dysplasia was present in 27 patients from seven families.

OBJECTIVE

Our purpose was to present the cutaneous findings that characterize this syndrome with particular attention given to the hair shaft abnormalities.

METHODS

Multiple field visits were used to gather data on phenotypic findings and prospectively evaluate their prevalence.

RESULTS

Corkscrew hair, an exaggeration of pili torti, represents the most striking feature of this syndrome. Prominent cutaneous findings include scalp keloids, follicular plugging, keratosis pilaris, xerosis, eczema, palmoplantar keratodermia, cutaneous syndactyly, onychodysplasia, and conjunctival neovascularization. Other features include typical facies, anteverted pinnae, malar hypoplasia, cleft lip and palate, and dental abnormalities.

CONCLUSION

A syndrome characterized by pili torti and corkscrew hairs, previously reported in only one patient, can be recognized.

[Hepatorenal syndrome]

The term "hepatorenal syndrome" is used to bring together a variety of syndromes whose common feature is liver and kidney parenchymal distress. For this reason, its use has been questioned by many workers. A subdivision into acute and chronic forms is proposed and emphasis is placed on the common physiopathogenetic processes, together with the notable importance of DIC. This approach is supported by reference to a series of 36 chronic and 6 acute cases.