Role of p38MAPK in ultrastructural alterations of desmosomes in human ex vivo pemphigus model

Desmosomes interconnect epithelial cells together and are abundant in tissues constantly challenged by shear forces. They are composed of different isoforms of intercellular adhesion proteins which include desmogleins (Dsg) and desmocollins (Dsc). These proteins of apposing cells interact in homophilic and heterophilic manner thereby conferring integrity to the tissue. When this crucial role of desmosomes is compromised, several desmosome-associated diseases such as pemphigus may occur. Pemphigus is a blistering disease of the skin and oral mucosa. It is caused by anti-Dg3 and anti-Dsg1 autoantibodies that bind to the extracellular domains of the desmogleins and perturb their interaction. There are different phenotypes of the disease depending on the autoantibody profiles. Pemphigus vulgaris (PV) is caused by autoantibodies (PV-IgG) targeting Dsg1 and Dsg3 whereas pemphigus foliaceus (PF) is associated with autoantibodies against Dsg1 only. Pemphigus vulgaris is recognized as two sub-types; i.e, the mucosal-dominant form (mdPV) caused by anti-Dsg3 autoantibodies and the mucocutaneus (mcPV) variant caused by both anti-Dsg1 and anti-Dsg3 autoantibodies. Several lines of evidence demonstrated that pemphigus is caused by disruption of Dsg interaction when the autoantibodies are interposed between the interacting Dsg (steric hindrance) and signaling triggered by autoantibody binding. It has been widely accepted that different signaling pathways work in concert in the modulation of desmosome structure and dynamics. p38 mitogen activated protein kinase (p38MAPK) has been extensively studied and its phosphorylation was detected in cell cultures in response to PV-IgG binding as well as in skin lesions of pemphigus patients. Pharmacological inactivation of this pathway attenuated cell dissociation in cultures and blister formation in murine models. However, no data was available with respect to the role of p38MAPK in blister formation in human skin and mucosa. Therefore, we tested the dependency of blister formation and desmosome ultrastructural alteration on p38MAPK signaling induced by PV-IgG in human skin and mucosa explant cultures. Accordingly, we adapted the existing ex vivo skin model and also established a novel ex vivo mucosa model, and employed histological, immune-histochemical as well as electron microscopy analyses to determine the role of p38MAPK signaling in PV pathogenesis. Human skin biopsies were treated with the mouse monoclonal Dsg3-specific antibodyAK23, in comparison to antibody fractions from patients with mucocutaneous PV (mcPV-IgG) or mucosal PV (mdPV-IgG). mcPV-IgG only were sufficient to induce blisters as well as alterations in desmosome ultrastructure. In contrast, in human labial mucosa explants both AK23 and mdPV-IgG were sufficient to induce blisters as well as alterations in desmosome ultrastructure. Moreover, inhibition of p38MAPK using the specific inhibitor SB202190 was effective to avert blister formation, rescue desmosome size and number as well as preserved keratin filament association with desmosomal plaques in human skin. However, in the newly established human ex vivo mucosa model, inhibition of p38MAPK with specific inhibitors SB202190 and SB203580 was not effective to prevent these alterations. Taken together, our data demonstrate that p38MAPK plays a key role in blister formation through modulation of desmosome ultrastructure in human skin. In contrast, blister formation and associated ultrastructural changes of desmosomes in mucosa may depend on steric hindrance and other signaling pathways independent of p38MAPK

Plasmonic Properties of Nanoparticle and Two Dimensional Material Integrated Structure

Recently, various groups have demonstrated nano-scale engineering of nanostructures for optical to infrared wavelength plasmonic applications. Most fabrication technique processes, especially those using noble metals, requires an adhesion layer. Previously proposed theoretical work to support experimental measurement often neglect the effect of the adhesion layers. The first finding of this work focuses on the impact of the adhesion layer on nanoparticle plasmonic properties. Gold nanodisks with a titanium adhesion layer are investigated by calculating the scattering, absorption, and extinction cross-section with numerical simulations using a finite difference time domain (FDTD) method. I demonstrate that a gold nanodisk with an adhesive layer significantly shifts the plasmon resonance relative to one without adhesion material. In addition, the adhesive layer also introduces stronger damping and decay time. Next, I investigate the plasmonic properties and effects of dielectric environment of black phosphorene (BP), a newly discovered anisotropic 2D material. Results suggest that the surface plasmon properties of a black phosphorene nanoribbon could be exploited to probe the efficiency of edge plasmonic enhanced absorption. Furthermore, the enhanced absorption of periodic BP nanoribbons is affected strongly by high density free carriers in BP nanoribbon geometries from mid-infrared to high infrared regime. Also when adding a thin dielectric shielding layer, such as hexagonal boron nitride, in addition to preserving the edge mode plasmonic nature of BP, it also allows for an unprecedented control of the absorption resonance energy. Finally, I also show monolayer graphene surface plasmon hybridization with hyperbolic phonon polarization local density of state of hyperbolic ferroelectric LiNbO3. The results show that the dispersion mode hybridization process is significantly regulated by a electrostatic gated single graphene and double graphene layer in addition to the ferroelectric layer size. The spontaneous emission (SE) rate the hyperbolic band contribution of LiNbO3 with graphene integrated system elucidated enhancement and inhibit spontaneous emission. Specially, the SE rate between in hybrid system is always smaller than that of the bulk in the hyperbolic band region with higher chemical potential

Role of p38MAPK in ultrastructural alterations of desmosomes in human ex vivo pemphigus model

Desmosomes interconnect epithelial cells together and are abundant in tissues constantly challenged by shear forces. They are composed of different isoforms of intercellular adhesion proteins which include desmogleins (Dsg) and desmocollins (Dsc). These proteins of apposing cells interact in homophilic and heterophilic manner thereby conferring integrity to the tissue. When this crucial role of desmosomes is compromised, several desmosome-associated diseases such as pemphigus may occur. Pemphigus is a blistering disease of the skin and oral mucosa. It is caused by anti-Dg3 and anti-Dsg1 autoantibodies that bind to the extracellular domains of the desmogleins and perturb their interaction. There are different phenotypes of the disease depending on the autoantibody profiles. Pemphigus vulgaris (PV) is caused by autoantibodies (PV-IgG) targeting Dsg1 and Dsg3 whereas pemphigus foliaceus (PF) is associated with autoantibodies against Dsg1 only. Pemphigus vulgaris is recognized as two sub-types; i.e, the mucosal-dominant form (mdPV) caused by anti-Dsg3 autoantibodies and the mucocutaneus (mcPV) variant caused by both anti-Dsg1 and anti-Dsg3 autoantibodies. Several lines of evidence demonstrated that pemphigus is caused by disruption of Dsg interaction when the autoantibodies are interposed between the interacting Dsg (steric hindrance) and signaling triggered by autoantibody binding. It has been widely accepted that different signaling pathways work in concert in the modulation of desmosome structure and dynamics. p38 mitogen activated protein kinase (p38MAPK) has been extensively studied and its phosphorylation was detected in cell cultures in response to PV-IgG binding as well as in skin lesions of pemphigus patients. Pharmacological inactivation of this pathway attenuated cell dissociation in cultures and blister formation in murine models. However, no data was available with respect to the role of p38MAPK in blister formation in human skin and mucosa. Therefore, we tested the dependency of blister formation and desmosome ultrastructural alteration on p38MAPK signaling induced by PV-IgG in human skin and mucosa explant cultures. Accordingly, we adapted the existing ex vivo skin model and also established a novel ex vivo mucosa model, and employed histological, immune-histochemical as well as electron microscopy analyses to determine the role of p38MAPK signaling in PV pathogenesis. Human skin biopsies were treated with the mouse monoclonal Dsg3-specific antibodyAK23, in comparison to antibody fractions from patients with mucocutaneous PV (mcPV-IgG) or mucosal PV (mdPV-IgG). mcPV-IgG only were sufficient to induce blisters as well as alterations in desmosome ultrastructure. In contrast, in human labial mucosa explants both AK23 and mdPV-IgG were sufficient to induce blisters as well as alterations in desmosome ultrastructure. Moreover, inhibition of p38MAPK using the specific inhibitor SB202190 was effective to avert blister formation, rescue desmosome size and number as well as preserved keratin filament association with desmosomal plaques in human skin. However, in the newly established human ex vivo mucosa model, inhibition of p38MAPK with specific inhibitors SB202190 and SB203580 was not effective to prevent these alterations. Taken together, our data demonstrate that p38MAPK plays a key role in blister formation through modulation of desmosome ultrastructure in human skin. In contrast, blister formation and associated ultrastructural changes of desmosomes in mucosa may depend on steric hindrance and other signaling pathways independent of p38MAPK

The abundance, diversity and distribution pattern of avian species in the Fentie Community Conservation Area, Ethiopia

This study aimed to investigate the species abundance, diversity, and distribution pattern of avifauna in the Fentie Community Conservation Area, East Gojjam, surrounded by farmlands, settlements and mountain ranges. The study carried out in both dry and wet seasons. The study area was stratified based on the four habitat types: forest, woodland, farmland, and shrubland. The point count method was employed in the forest and woodland habitats, and the line-transect used for farmland and shrubland. Data were analyzed using SPSS version 20. In this study, 92 avian species belonging to 38 families were identified during both dry and wet seasons. The highest avian diversity was observed in the forest habitat (H= 4.101 and H= 4.056), followed by shrubland (H=3.874 and H= 3.848), during both dry and wet seasons, respectively. The highest number of birds was recorded in the dry season (n=703) than the wet season (n=439). There was a significant difference in abundance between the habitat types in the dry season (α=0.05, H’=4.142, df=3 and P=0.038) as well as in the wet season (α=0.05, H’=4.113, df=3 and P=0.109). The fewer bird species diversity and abundance discovered in the farmland could be caused by the cleansing of the vegetation for cultivation as it was seen in the study area. Thus, protection of the area is crucial for wildlife conservation especially for birds to enrich their diversity, abundance, and to maintain the natural ecological balance

Especies productores de resina y gomas naturales en Etiopía y la aplicación potencial de sus productos

Ethiopia is one of the countries well endowed with various species of Acacia, Boswellia and Commiphora that are known to produce gum arabic, frankincense and myrrh, respectively. Over 60 gum and resin bearing species are found in the country. The total area of oleo-gum resin bearing woodlands cover about 2.9 million ha of land in the country, with over 300,000 metric tons of natural gum production potential. Boswellia papyrifera is a chief gum resin producing tree species in Ethiopia. The total area covered by the species is estimated to be more than 1.5 million ha. Frankincense and myrrh are used in medicines, beverages and liqueurs, cosmetics, detergents, creams and perfumery, paints, adhesives and dyes manufacturing. Gum Arabic is used as stabilizing, in food and drink industries; in pharmaceuticals, in printing and textile industries. Despite the enormous socio-economic importance of these natural products, the species are declining at an alarming rate due to degradation resulted from agricultural expansion, overgrazing, fire, poor incense harvesting practices, etc. Therefore, research and development efforts and international collaborations could have strong potentials to the conservation, production and commercialization for the benefits of the local, national as well as the international communities.Etiopía es uno de los países que tiene varias especies de de Acacia, Boswellia y Commiphora que son utilizados para la producción de goma arábiga, resina y mirra respectivamente, y en el país se encuentran más de 60 especies productoras de resinas naturales. El área total cubierto por especies productoras de resinas naturales se estima en 2,9 millones de hectáreas en todo el país, con una producción potencial de 300.000 toneladas métricas. Boswellia papyrifera es la especies gran productora de resina en Etiopia. El área total cubierta por esta especie se estima por encima de 1,5 millones de ha. La resina y la mirra se usan en la preparación de medicinas, bebidas y licores, cosméticos, detergentes, cremas y perfumerías, pinturas y adhesivos. La goma arábiga se usa como estabilizador en las industrias alimentarías; y en las industrias farmacéuticas, imprentas y textiles. Aunque las resinas natural tienes enormes importancias socioeconómicas, las especies están disminuyendo alarmantemente debido a las degradaciones por la expansión de agricultura, sobre pastoreo, fuego, mala práctica de resinación etc. Esfuerzos en investigación y desarrollo y colaboraciones internacionales podrían tener fuertes potencias en la conservación, producción y comercialización para el beneficio de las comunidades locales, nacionales e internacionales

Mechanisms Causing Acantholysis in Pemphigus-Lessons from Human Skin

Pemphigus vulgaris (PV) is an autoimmune bullous skin disease caused primarily by autoantibodies (PV-IgG) against the desmosomal adhesion proteins desmoglein (Dsg)1 and Dsg3. PV patient lesions are characterized by flaccid blisters and ultrastructurally by defined hallmarks including a reduction in desmosome number and size, formation of split desmosomes, as well as uncoupling of keratin filaments from desmosomes. The pathophysiology underlying the disease is known to involve several intracellular signaling pathways downstream of PV-IgG binding. Here, we summarize our studies in which we used transmission electron microscopy to characterize the roles of signaling pathways in the pathogenic effects of PV-IgG on desmosome ultrastructure in a human ex vivo skin model. Blister scores revealed inhibition of p38MAPK, ERK and PLC/Ca2+ to be protective in human epidermis. In contrast, inhibition of Src and PKC, which were shown to be protective in cell cultures and murine models, was not effective for human skin explants. The ultrastructural analysis revealed that for preventing skin blistering at least desmosome number (as modulated by ERK) or keratin filament insertion (as modulated by PLC/Ca2+) need to be ameliorated. Other pathways such as p38MAPK regulate desmosome number, size, and keratin insertion indicating that they control desmosome assembly and disassembly on different levels. Taken together, studies in human skin delineate target mechanisms for the treatment of pemphigus patients. In addition, ultrastructural analysis supports defining the specific role of a given signaling molecule in desmosome turnover at ultrastructural level

Role of PKC and ERK Signaling in Epidermal Blistering and Desmosome Regulation in Pemphigus

Desmosomes reinforce cohesion of epithelial cells at the interface between adjacent cells. They include the cadherin-type adhesion molecules desmoglein 1 (Dsg1) and Dsg3. Pemphigus vulgaris (PV) is an autoimmune disease in which circulating autoantibodies (PV-IgG) targeting Dsg1 and 3 cause characteristic epidermal blister formation. It has been shown that PV-IgG binding induced activation of kinases such as ERK and PKC, and inhibition of these signaling pathways prevented loss of cell cohesion in cell cultures. However, the role of Erk and PKC in blister formation and regulation of desmosome ultrastructure in human skin are unknown. Accordingly, we assessed the role of PKC and ERK signaling pathways in blister formation and regulation of desmosome ultrastructure in human epidermis. Here we performed electron microscopy analyses using human skin explants injected with PV-IgG together with inhibitors for PKC or ERK signaling. Inhibition of PKC was not effective to prevent suprabasal blister formation or ultrastructural alterations of desmosomes. In contrast, inhibition of ERK signaling significantly ameliorated blister formation and decrease in the number of desmosomes whereas shortening and splitting of desmosomes and keratin filament insertion were not different from samples treated with PV-IgG alone. However, apical desmosomes between basal and suprabasal cells remained unaltered when ERK signaling was inhibited. Therefore, our results show that inhibition of ERK but not PKC signaling appears to be effective to ameliorate blistering and alterations of desmosome ultrastructure triggered by PV-IgG in human skin

Physical and Proximate Characterization of Anchote (Coccinia abyssinica) Accessions Grown under Hawassa and Wondo Genet Conditions, Southern Ethiopia

This research was undertaken to investigate the effects of anchote accessions and growing areas on the physical and proximate composition of the roots. The physical properties were measured using standard measurements. The major and minor diameters as well as the root peel thickness were measured using a digital caliper. The proximate composition was assessed using standard methods. Both the physical properties (major and minor diameters, aspect ratio, root peel thickness, peel proportion to root and root densities) and proximate compositions of anchote roots were significantly influenced by accessions type and growing sites. Over all, better quality, in terms root peel thickness and peel to root ratio, were observed for the accessions grown at Hawassa. The anchote accessions grown at Wondo Genet site were observed to have higher levels of crude protein, crude fiber and gross energy than those grown at Hawassa. Higher ash content was associated to the accessions grown at Hawassa site. Keywords: Anchote, physical properties, aspect ratio, major diameter, minor diameter, root peel thickness, root density, proximate compositio

The Prevalence of Malaria in Tselemti Wereda, North Ethiopia: A Retrospective Study

BACKGROUND: A significant segment of the world’s population is at risk of contracting malaria infection at any one time. In Ethiopia, sustained control efforts have been made in the past decade to fight malaria. Yet, it remains as the major cause of morbidity, mortality and socioeconomic problems in the country. The intensified control of malaria can further be augmented by analyzing health facility based malaria data. Hence, the aim of this study was to determine the magnitude of malaria infection in Northwest Ethiopia.METHODS: A retrospective record review was conducted in Northwest Ethiopia from February-April 2016. All blood film results reported between January 2013 and December 2015 in the seven health centers were extracted and analyzed.RESULTS: A total of 41,773 patients with chief malaria complaint were screened for malaria in the three years period. The overall prevalence of microscopically confirmed malaria was 28.1%. Males (29.5%) were more affected by malaria than females (26.5%). Malaria was also higher in the age group >15 years (32.6%) followed by 5-15 years (29.3%) and under-five children (20.5%). Plasmodium falciparum, Plasmodium vivax and mixed infectionsaccounted for 58.2%, 35.5% and 6.3%, respectively. The highest prevalence of confirmed malaria cases was observed during spring (35.6%) and summer (25.1%). Higher prevalence of slide positive malaria was recorded in Dima (46.1%), Cherecher (45.3%) andFyel wuha (35.3%) health centers.CONCLUSION: Malaria specific outpatient cases were high in the study area. Both plasmodia species were of public health significance in the area with predominance of Plasmodiumfalciparum

Adrenergic Signaling-Induced Ultrastructural Strengthening of Intercalated Discs via Plakoglobin Is Crucial for Positive Adhesiotropy in Murine Cardiomyocytes

Intercalated discs (ICDs), which connect adjacent cardiomyocytes, are composed of desmosomes, adherens junctions (AJs) and gap junctions (GJs). Previous data demonstrated that adrenergic signaling enhances cardiac myocyte cohesion, referred to as positive adhesiotropy, via PKA-mediated phosphorylation of plakoglobin (PG). However, it was unclear whether positive adhesiotropy caused ultrastructural modifications of ICDs. Therefore, we further investigated the role of PG in adrenergic signaling-mediated ultrastructural changes in the ICD of cardiomyocytes. Quantitative transmission electron microscopy (TEM) analysis of ICD demonstrated that cAMP elevation caused significant elongation of area composita and thickening of the ICD plaque, paralleled by enhanced cardiomyocyte cohesion, in WT but not PG-deficient cardiomyocytes. STED microscopy analysis supported that cAMP elevation ex vivo enhanced overlap of desmoglein-2 (Dsg2) and N-cadherin (N-cad) staining in ICDs of WT but not PG-deficient cardiomyocytes. For dynamic analyses, we utilized HL-1 cardiomyocytes, in which cAMP elevation induced translocation of Dsg2 and PG but not of N-cad to cell junctions. Nevertheless, depletion of N-cad but not of Dsg2 resulted in a decrease in basal cell cohesion whereas positive adhesiotropy was abrogated in monolayers depleted for either Dsg2 or N-cad. In the WT mice, ultrastrutural changes observed after cAMP elevation were paralleled by phosphorylation of PG at serine 665. Our data demonstrate that in murine hearts adrenergic signaling enhanced N-cad and Dsg2 in the ICD paralleled by ultrastrutural strengthening of ICDs and that effects induced by positive adhesiotropy were strictly dependent on Pg