RESUMEN
The Order Lepidoptera contains nearly 160,000 described species and most of them are specialist herbivores that use restricted plant species as hosts. Speciation that originated from host shift is one of the important factors for the diversification of Lepidoptera. Because plants prepare secondary metabolites for defense against herbivores, with varying profiles of the components among different plant taxa, the specialist herbivores need to be adapted to the toxic substances unique to their host plants. Swallowtail butterflies of the genus Papilio consist of over 200 species. Approximately 80% of them utilize Rutaceae plants, and among the remaining species, a specific subgroup uses phylogenetically distant Apiaceae plants as larval hosts. Rutaceae and Apiaceae commonly contain toxic secondary metabolites, furanocoumarins, and molecular phylogenetic studies support the concept that Apiaceae feeders were derived from Rutaceae feeders. Molecular mechanisms underlying furanocoumarin tolerance in Papilio butterflies have been investigated almost exclusively in an Apiaceae feeder by an in vitro assay. In contrast, there is little information regarding the Rutaceae feeders. Here, we focused on a Rutaceae feeder, Papilio xuthus, and identified two furanocoumarin-responsive cytochrome P450-6B (CYP6B) genes, of which one was an ortholog of a furanocoumarin-metabolizing enzyme identified in the Apiaceae-feeding Papilio while the other was previously unreported. We further conducted in vivo functional analysis using the CRISPR/Cas9 system, revealing a contribution of these CYP6Bs to furanocoumarin tolerance of P. xuthus larvae. Our findings suggest that co-option of furanocoumarin-metabolizing CYP6B enzymes at least partially contributed to the host shift from Rutaceae to Apiaceae in Papilio butterflies.
Asunto(s)
Mariposas Diurnas , Sistema Enzimático del Citocromo P-450 , Furocumarinas , Rutaceae , Animales , Mariposas Diurnas/enzimología , Mariposas Diurnas/genética , Mariposas Diurnas/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Sistema Enzimático del Citocromo P-450/genética , Furocumarinas/metabolismo , Furocumarinas/química , Rutaceae/metabolismo , Rutaceae/genética , Rutaceae/química , Larva/metabolismo , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Proteínas de Insectos/química , Filogenia , HerbivoriaRESUMEN
Outcomes after repair of chronic rotator cuff injuries remain suboptimal. Type-1 collagen-rich tendon hydrogel was previously reported to improve healing in a rat chronic rotator cuff injury model. Stem cell seeding of the tendon hydrogel improved bone quality in the same model. This study aimed to examine whether there was a synergistic and dose-dependent effect of platelet-rich plasma (PRP) on tendon-bone interface healing by combining PRP with stem cell-seeded tendon hydrogel. Human cadaveric tendons were processed into a hydrogel. PRP was prepared at two different platelet concentrations: an initial concentration (initial PRP group) and a higher concentration (concentrated PRP group). Tendon hydrogel was mixed with adipose-derived stem cells and one of the platelet concentrations. Methylcellulose, as opposed to saline, was used as a negative control due to comparable viscosity. The supraspinatus tendon was detached bilaterally in 33 Sprague-Dawley rats (66 shoulders). Eight weeks later, each detached tendon was repaired, and a hydrogel mixture or control was injected at the repair site. Eight weeks after repair, shoulder samples were harvested and assigned for biomechanical testing (n = 42 shoulders) or a combination of bone morphological and histological assessment (n = 24 shoulders). Biomechanical testing showed significantly higher failure load and stiffness in the concentrated PRP group than in control. Yield load in the initial and concentrated PRP groups were significantly higher than that in the control. There were no statistically significant differences between the initial and concentrated PRP groups. The addition of the highly concentrated PRP to stem cells-seeded tendon hydrogel improved healing biomechanically after chronic rotator cuff injury in rats compared to control. However, synergistic and dose-dependent effects were not seen.
Asunto(s)
Plasma Rico en Plaquetas , Lesiones del Manguito de los Rotadores , Humanos , Ratas , Animales , Lesiones del Manguito de los Rotadores/terapia , Hidrogeles/farmacología , Ratas Sprague-Dawley , Cicatrización de Heridas , Células Madre , Fenómenos BiomecánicosRESUMEN
PURPOSE: Partial rotator cuff tears can cause shoulder pain and dysfunction and are more common than complete tears. However, few studies examine partial injuries in small animals and, therefore a robust, clinically relevant model may be lacking. This study aimed to fully characterize the established rat model of partial rotator cuff injury over time and determine if it models human partial rotator cuff tears. METHODS: We created a full-thickness, partial-width injury at the supraspinatus tendon-bone interface bilaterally in 31 Sprague-Dawley rats. Rats were euthanized immediately, and at 2-, 3-, 4-, and 8-weeks after surgery. Fourteen intact shoulders were used as controls. Samples were assessed biomechanically, histologically, and morphologically. RESULTS: Biomechanically, load to failure in controls and 8 weeks after injury was significantly greater than immediately and 3 weeks after injury. Load to failure at 8 weeks was comparable to control. However, the locations of failure were different between intact shoulders and partially injured samples. Bone mineral density at 8 weeks was significantly greater than that at 2 and 3 weeks. Although no animals demonstrated propagation to complete tear and the injury site remodeled histologically, the appearance at 8 weeks was not identical to that in the controls. CONCLUSIONS: The biomechanical properties and bone quality decreased after the injury and was restored gradually over time with full restoration by 8 weeks after injury. However, the findings were not equivalent to the intact shoulder. This study demonstrated the limitations of the current model in its application to long-term outcome studies, and the need for better models that can be used to assess chronic partial rotator cuff injuries. CLINICAL RELEVANCE: There is no small animal model that mimics human chronic partial rotator cuff tears, which limits our ability to improve care for this common condition.
RESUMEN
BACKGROUND: The process of early development varies across the species-rich phylum Arthropoda. Owing to the limited research strategies for dissecting lineage-specific processes of development in arthropods, little is known about the variations in early arthropod development at molecular resolution. The Theridiidae spider, Parasteatoda tepidariorum, has its genome sequenced and could potentially contribute to dissecting early embryonic processes. RESULTS: We present genome-wide identification of candidate genes that exhibit locally restricted expression in germ disc forming stage embryos of P. tepidariorum, based on comparative transcriptomes of isolated cells from different regions of the embryo. A subsequent pilot screen by parental RNA interference identifies three genes required for body axis formation. One of them is a GATA-like gene that has been fast evolving after duplication and divergence from a canonical GATA family gene. This gene is designated fuchi nashi (fuchi) after its knockdown phenotypes, where the cell movement toward the formation of a germ disc was reversed. fuchi expression occurs in cells outside a forming germ disc and persists in the endoderm. Transcriptome and chromatin accessibility analyses of fuchi pRNAi embryos suggest that early fuchi activity regulates chromatin state and zygotic gene activation to promote endoderm specification and pattern formation. We also show that there are many uncharacterized genes regulated by fuchi. CONCLUSIONS: Our genome-based research using an arthropod phylogenetically distant from Drosophila identifies a lineage-specific, fast-evolving gene with key developmental roles in one of the earliest, genome-wide regulatory events, and allows for molecular exploration of the developmental variations in early arthropod embryos.
Asunto(s)
Artrópodos , Arañas , Animales , Artrópodos/genética , Cromatina/metabolismo , Endodermo , Regulación del Desarrollo de la Expresión Génica , Arañas/genética , Activación Transcripcional , CigotoRESUMEN
Patterning along an axis of polarity is a fundamental step in the development of a multicellular animal embryo. In the cellular field of an early spider embryo, Hedgehog signaling operates to specify a "fuzzy" French-flag-like pattern along the primary axis, which is related to the future anterior-posterior (A-P) axis. However, details regarding the generation and development of a diversity of cell states based on the embryo polarity are not known. To address this issue, we applied single-cell RNA sequencing to the early spider embryo consisting of approximately 2,000 cells. Our results confirmed that this technique successfully detected 3 cell populations corresponding to the germ layers and some transient cell states. We showed that the data from dissociated cells had sufficient information for reconstruction of a correct global A-P polarity of the presumptive ectoderm, without clear segregation of specific cell states. This outcome is explained by the varied but differentially overlapping expression of Hedgehog-signal target genes and newly identified marker genes. We also showed that the data resources generated by the transcriptome analysis are applicable to a genome-wide search for genes whose expression is spatially regulated, based on the detection of pattern similarity. Furthermore, we performed single-nucleus RNA sequencing, which was more powerful in detecting emerging cell states. The single-cell and single-nucleus transcriptome techniques will help investigate the pattern-forming processes in the spider model system in an unbiased, comprehensive manner. We provided web-based resources of these transcriptome datasets for future studies of pattern formation and cell differentiation.
RESUMEN
Remodeling of multicellular architecture is a critical developmental process for shaping the axis of a bilaterally symmetric animal body and involves coordinated cell-cell interactions and cell rearrangement. In arthropods, the early embryonic process that leads to the segmented body axis varies at the cellular and molecular levels depending on the species. Developmental studies using insect and spider model species have provided specific examples of these diversified mechanisms that regulate axis formation and segmentation in arthropod embryos. However, there are few theoretical models for how diversity in the early embryonic process occurred during evolution, in part because of a limited computational infrastructure. We developed a virtual spherical-shaped multicellular platform to reproduce body axis-forming processes. Each virtual cell behaves according to the cell vertex model, with the computational program organized in a hierarchical order from cells and tissues to whole embryos. Using an initial set of two different mechanical states for cell differentiation and global directional signals that are linked to the planar polarity of each cell, the virtual cell assembly exhibited morphogenetic processes similar to those observed in spider embryos. We found that the development of an elongating body axis is achieved through implementation of an interactive cell polarity parameter associated with edge tension at the cell-cell adhesion interface, with no local control of the cell division rate and direction. We also showed that modifying the settings can cause variation in morphogenetic processes. This platform also can embed a gene network that generates waves of gene expression in a virtual dynamic multicellular field. This study provides a computational platform for testing the development and evolution of animal body patterns.
RESUMEN
Background: Some strains of Streptococcus mitis exhibit ß-hemolysis due to the ß-hemolytic activity of cholesterol-dependent cytolysin (CDC). Recently, a gene encoding an atypical lectinolysin-related CDC was found in S. mitis strain Nm-76. However, the product of this gene remains uncharacterized. We aimed to characterize this atypical CDC and its molecular functions and contribution to the pathogenicity of S. mitis strain Nm-76. Methods: Phylogenetic analysis of the CDC gene was conducted based on the web-deposited information. The molecular characteristics of CDC were investigated using a gene-deletion mutant strain and recombinant proteins expressed in Escherichia coli. Results: The gene encoding CDC found in Nm-76 and its homolog are distributed among many S. mitis strains. This CDC is phylogenetically different from other previously characterized CDCs, such as S. mitis-derived human platelet aggregation factor (Sm-hPAF)/lectinolysin and mitilysin. Because this CDC possesses an additional N-terminal domain, including a discoidin motif, it was termed discoidinolysin (DLY). In addition to the preferential lysis of human cells, DLY displayed N-terminal domain-dependent facilitation of human erythrocyte aggregation and intercellular associations between human cells. Conclusion: DLY functions as a hemolysin/cytolysin and erythrocyte aggregation/intercellular association molecule. This dual-function DLY could be an additional virulence factor in S. mitis.
RESUMEN
BACKGROUND: Transsphenoidal endoscopic endonasal surgery (EES) provides effective treatment for patients with lesions of the sella turcica. The endoscopic technique requires different instrumentation, which depends on the gross anatomy of the nasal cavity. The treatment of lateral lesions is more challenging in EES. OBJECTIVE: To evaluate the effect of preoperative simulation using multiple anatomic landmarks. METHODS: Pre- and postoperative tumor volumes were analyzed in 33 patients with nonfunctioning pituitary adenomas who underwent EES (Knosp grades 3 and 4). The surgical working angle and space were three-dimensionally simulated at the plane of the anterior/posterior surgical field (tuberculum sellae/posterior clinoid process) using multiple anatomic landmarks of high-resolution computed tomography scans, such as nasal piriform aperture (proximal surgical corridor), and the width of bilateral vidian canals or lamina perpendicularis of palatine bone (distal surgical corridor). Receiver operating characteristic curves for the removed tumor volume were used to determine the cutoff value for the simulated working angle and space. RESULTS: Simulated working space at the plane of tuberculum sellae using piriform aperture and lamina perpendicularis of palatine bone was associated with the removed tumor volume in the cavernous sinus. Patients with a larger working space (≥42.7 mm) significantly showed a higher removed tumor volume ( P = .023). There was no relationship between other parameters and the removed tumor volume. CONCLUSION: A new method to predict the surgical field for cavernous sinus lesions around sella turcica was successfully established. Further studies are needed to define and expand applications of this simulation method.
Asunto(s)
Adenoma , Seno Cavernoso , Neuroendoscopía , Neoplasias Hipofisarias , Adenoma/diagnóstico por imagen , Adenoma/patología , Adenoma/cirugía , Seno Cavernoso/diagnóstico por imagen , Seno Cavernoso/cirugía , Humanos , Neuroendoscopía/métodos , Neoplasias Hipofisarias/diagnóstico por imagen , Neoplasias Hipofisarias/patología , Neoplasias Hipofisarias/cirugía , Silla Turca/diagnóstico por imagen , Silla Turca/cirugíaRESUMEN
Early detection of limb ischemia, strokes, and heart attacks may be enabled via long-term monitoring of arterial health. Early stenosis, decreased blood flow, and clots are common after surgical vascular bypass or plaque removal from a diseased vessel and can lead to the above diseases. Continuous arterial monitoring for the early diagnosis of such complications is possible by implanting a sensor during surgery that is wirelessly monitored by patients after surgery. Here, we report the design of a wireless capacitive sensor wrapped around the artery during surgery for continuous post-operative monitoring of arterial health. The sensor responds to diverse artery sizes and extents of occlusion in vitro to at least 20 cm upstream and downstream of the sensor. It demonstrated strong capability to monitor progression of arterial occlusion in human cadaver and small animal models. This technology is promising for wireless monitoring of arterial health for pre-symptomatic disease detection and prevention.
RESUMEN
Type III cadherin represents the ancestral form of classical cadherin in bilaterian metazoans. Drosophila possesses type III and type IVa cadherins, known as DN- and DE-cadherins, respectively. Mature DN- and DE-cadherins have 15 and 7 extracellular cadherin domain (EC) repeats, respectively, with DN-cadherin EC6-EC11 homologous to DE-cadherin EC1-EC6. These EC repeats contain predicted complete or partial Ca2+-free inter-EC linkers that potentially contribute to adhesion. Comparative structure-function studies of DN- and DE-cadherins may help us understand the ancestral and derived states of classical cadherin-mediated adhesion mechanisms. Here, using bead aggregation assays, we found that DN-cadherin EC1-EC11 and DE-cadherin EC1-EC6 exhibit Ca2+-dependent adhesive properties. Using high-speed atomic force microscopy (HS-AFM) imaging in solution, we show that both DN- and DE-cadherin ectodomains share a common morphological framework consisting of a strand-like and a globule-like portion. Furthermore, the DN-cadherin EC repeats are highly variable, flexible in morphology and have at least three bendable sites, one of which is located in EC6-EC11 and can act as a flexible hinge. Our findings provide insights into diversification of classical cadherin-mediated adhesion mechanisms. This article has an associated First Person interview with the first author of the paper.
Asunto(s)
Cadherinas , Drosophila , Animales , Cadherinas/química , Cadherinas/genética , Adhesión Celular , Microscopía de Fuerza Atómica , Dominios ProteicosRESUMEN
BACKGROUND: We previously reported the development of a scaffold-free Bio three-dimensional (3D) nerve conduit from normal human dermal fibroblasts (NHDFs). The aim of this study was to investigate the regenerative mechanism of peripheral nerve cells using a Bio 3D conduit in a rat sciatic nerve defect model. METHODS: Bio 3D conduits composed of NHDFs were developed, and cell viability was evaluated using a LIVE/DEAD cell viability assay immediately before transplantation and 1-week post-surgery. Tracking analysis using PKH26-labeled NHDFs was performed to assess the distribution of NHDFs within the regenerated nerve and the differentiation of NHDFs into functional Schwann cells (SCs). RESULTS: The assessment of the viability of cells within the Bio 3D conduit showed high cell viability both immediately before transplantation and 1-week post-surgery (88.56 ± 1.70 and 87.58 ± 9.11, respectively). A modified Masson's trichrome staining of the Bio 3D conduit revealed the formation of a prominent extracellular matrix (ECM) in between the cells. We observed, via tracking analysis, that the tube-like distribution of the NHDFs remained stable, the majority of the regenerated axons had penetrated this structure and PKH26-labeled cells were also positive for S-100. CONCLUSION: Abundant ECM formation resulted in a stable tube-like structure of the Bio 3D conduit with high cell viability. NHDFs in the Bio 3D conduit have the potential to differentiate into SCs-like cells.
Asunto(s)
Regeneración Nerviosa , Nervio Ciático , Animales , Axones , Fibroblastos , Humanos , Ratas , Células de SchwannRESUMEN
A 50s women underwent laparoscopic abdominoperineal resection(APR)for rectal cancer. Laparotomy was performed on the 8th postoperative day because of intestinal obstruction. An internal hernia was observed at the pelvic floor and the hernia orifice was found at the retroperitoneum that was sutured in the initial operation. On the other hand, the jejunum near the Treitz ligament was twisted, resulting in ischemic necrosis. The reason of the internal hernia is considered that a suction drain placed during the initial operation may have caused the rupture of the fragile part of the sutured peritoneum. Furthermore, increase of intra-abdominal pressure due to the internal hernia may have exacerbated the torsion of the jejunum near the Treitz ligament. This is probably due to the failure to the adequate reposition of the small intestine at the end of the initial operation. There is no consensus of the need for retroperitoneal sutures for APR. Currently, we only spray anti-adhesion agents on the pelvic floor without retroperitoneal reconstruction. Although the mobilization of small intestine is important to provide a good operative view in laparoscopic colorectal surgery, it is also important to confirm the reposition of the small intestine at the end of surgery.
Asunto(s)
Hernia Abdominal , Laparoscopía , Proctectomía , Femenino , Hernia Abdominal/cirugía , Humanos , Hernia Interna , Yeyuno/cirugía , Ligamentos , Diafragma Pélvico , PeritoneoRESUMEN
Streptococcus pseudopneumoniae (SPpn) is a relatively new species closely related to S. pneumoniae (SPn) and S. mitis (SM) belonging to the Mitis group of the genus Streptococcus (MGS). Although genes encoding various pneumococcal virulence factors have been observed in the SPpn genome, the pathogenicity of SPpn against human, including the roles of virulence factor candidates, is still unclear. The present study focused on and characterized a candidate virulence factor previously reported in SPpn with deduced multiple functional domains, such as lipase domain, two lectin domains, and cholesterol-dependent cytolysin-related domain using various recombinant proteins. The gene was found not only in SPpn but also in the strains of SM and SPn. Moreover, the gene product was expressed in the gene-positive strains as secreted and cell-bound forms. The recombinant of gene product showed lipase activity and human cell-binding activity depending on the function of lectin domain(s), but no hemolytic activity. Thus, based on the distribution of the gene within the MGS and its molecular function, the gene product was named mitilectin (MLC) and its contribution to the potential pathogenicity of the MLC-producing strains was investigated. Consequently, the treatment with anti-MLC antibody and the mlc gene-knockout significantly reduced the human cell-binding activity of MLC-producing strains. Therefore, the multifunctional MLC was suggested to be important as an adhesion molecule in considering the potential pathogenicity of the MLC-producing strains belonging to MGS, such as SPpn and SM.
Asunto(s)
Streptococcus mitis , Moléculas de Adhesión Celular , Colesterol , Citotoxinas , Humanos , Streptococcus , Streptococcus pneumoniaeRESUMEN
Hedgehog (Hh) signaling plays fundamental roles in animal body patterning. Understanding its mechanistic complexity requires simple tractable systems that can be used for these studies. In the early spider embryo, Hh signaling mediates the formation of overall anterior-posterior polarity, yet it remains unclear what mechanisms link the initial Hh signaling activity with body axis segmentation, in which distinct periodic stripe-forming dynamics occur depending on the body region. We performed genome-wide searches for genes that transcriptionally respond to altered states of Hh signaling. Characterization of genes negatively regulated by Hh signaling suggested that msx1, encoding a conserved transcription factor, functions as a key segmentation gene. Knockdown of msx1 prevented all dynamic processes causing spatial repetition of stripes, including temporally repetitive oscillations and bi-splitting, and temporally nonrepetitive tri-splitting. Thus, Hh signaling controls segmentation dynamics and diversity via msx1 These genome-wide data from an invertebrate illuminate novel mechanistic features of Hh-based patterning.
RESUMEN
We previously reported that a nerve conduit created from fibroblasts promotes nerve regeneration in a rat sciatic nerve model. This study aims to determine whether a nerve conduit created from bone marrow stromal cells (BMSCs) can promote nerve regeneration. Primary BMSCs were isolated from femur bone marrow of two Lewis rats, and cells at passages 4-7 were used. We created seven Bio 3D nerve conduits from BMSCs using a Bio-3D Printer. The conduits were transplanted to other Lewis rats to bridge 5-mm right sciatic nerve gaps (Bio 3D group, n = 7). We created two control groups: a silicone group (S group, n = 5) in which the same nerve gap was bridged with a silicone tube, and a silicone cell group (SC group, n = 5) in which the gap was bridged with a BMSC injection. Twelve weeks after transplantation, nerve regeneration was evaluated functionally and morphologically. In addition, PKH26-labeled BMSCs were used to fabricate a Bio 3D conduit that was transplanted for cell trafficking analysis. Electrophysiological study, kinematic analysis, wet muscle weight, and morphological parameters showed significantly better nerve regeneration in the Bio 3D group than in the S group or SC group. In immunohistochemical studies, sections from the Bio 3D group contained abundant S-100-positive cells. In cell trafficking analysis, PKH26-positive cells stained positive for the Schwann cell markers S-100, p75NTR, and GFAP. Bio 3D nerve conduits created from BMSCs can promote peripheral nerve regeneration in a rat sciatic nerve model through BMSC differentiation into Schwann-like cells.
Asunto(s)
Regeneración Tisular Dirigida , Células Madre Mesenquimatosas/citología , Regeneración Nerviosa/fisiología , Nervios Periféricos/fisiopatología , Potenciales de Acción , Animales , Fenómenos Biomecánicos , Supervivencia Celular , Rastreo Celular , Masculino , Músculos/patología , Tamaño de los Órganos , Ratas Endogámicas LewRESUMEN
PURPOSE: Tendons are difficult to heal owing to their hypocellularity and hypovascularity. Our laboratory has developed a tendon-derived hydrogel (tHG) that significantly improves tendon healing in an animal model. We hypothesized that a potential mechanism for improved healing with tHG is through the attraction of systemic stem cells. METHODS: Homing of systemic adipose-derived stem cells (ADSCs) to tendon injuries was assessed with acute and chronic injury models. Injury sites were treated with saline or tHG, and animals given a tail vein injection (TVI) of labeled ADSCs 1 week after treatment. One week following TVI, rats were harvested for histology. To further evaluate a potential difference in homing to tHG, a subcutaneous injection (SQI) model was used. Rats were treated with an SQI of saline, silicone, ADSCs in media, tHG, tHG + fibroblasts (FBs), or tHG + ADSCs on day 0. One week after SQI, rats underwent TVI with labeled ADSCs. Samples were harvested 2 or 3 weeks after SQI for analysis. Flow cytometry confirmed homing in the SQI model. RESULTS: Systemically delivered ADSCs homed to both acute tendon and chronic tendon-bone interface (TBI) injury sites. Despite their presence at the injury site, there was no difference in the number of macrophages, amount of cell proliferation, or angiogenesis 1 week after stem cell delivery. In an SQI model, ADSCs homed to tHG. There was no difference in the number of ADSCs homing to tHG alone versus tHG + ADSCs. However, there was an increase in the number of living cells, general immune cells, and T-cells present at tHG + ADSC versus tHG alone. CONCLUSIONS: The ADSCs home to tendon injury sites and tHG. We believe the attraction of additional systemic ADSCs is one mechanism for improved tendon and TBI healing with tHG. CLINICAL RELEVANCE: Treatment of tendon and TBI injuries with tHG can augment healing via homing of systemic stem cells.
Asunto(s)
Tejido Adiposo , Hidrogeles , Animales , Ratas , Células Madre , Tendones , Cicatrización de HeridasRESUMEN
Chronic wounds are a prominent concern, accounting for $25 billion of health care costs annually. Biofilms have been implicated in delayed wound closure, but they are susceptible to developing antibiotic resistance and treatment options continue to be limited. A novel collagen-rich hydrogel derived from human extracellular matrix presents an avenue for treating chronic wounds by providing appropriate extracellular proteins for healing and promoting neovascularization. Using the hydrogel as a delivery system for localized secretion of a therapeutic dosage of antibiotics presents an attractive means of maximizing delivery while minimizing systemic side effects. We hypothesize that the hydrogel can provide controlled elution of antibiotics leading to inhibition of bacterial growth and disruption of biofilm formation. The rate of antibiotic elution from the collagen-rich hydrogel and the efficacy of biofilm disruption was assessed with Pseudomonas aeruginosa Bacterial growth inhibition, biofilm disruption, and mammalian cell cytotoxicity were quantified using in vitro models. The antibiotic-loaded hydrogel showed sustained release of antibiotics for up to 24 h at therapeutic levels. The treatment inhibited bacterial growth and disrupted biofilm formation at multiple time points. The hydrogel was capable of accommodating various classes of antibiotics and did not result in cytotoxicity in mammalian fibroblasts or adipose stem cells. The antibiotic-loaded collagen-rich hydrogel is capable of controlled antibiotic release effective for bacteria cell death without native cell death. A human-derived hydrogel that is capable of eluting therapeutic levels of antibiotic is an exciting prospect in the field of chronic wound healing.
Asunto(s)
Antibacterianos , Hidrogeles , Animales , Antibacterianos/farmacología , Biopelículas , Colágeno , Humanos , Pseudomonas aeruginosaRESUMEN
Simultaneous, parental RNA interference (pRNAi) mediated knockdown of Hedgehog and Decapentaplegic (Dpp) signaling components, Pt-patched (Pt-ptc) and Pt-dpp, respectively, exhibited serious defects in the formation of the major embryonic axes in the model spider Parasteatoda tepidariorum. This paper describes a dataset of a custom oligonucleotide two-color microarray analysis that was carried out to compare the transcript expression levels between untreated (normal) and Pt-ptc + Pt-dpp double pRNAi embryos at late stage 5. Array spots that showed the intensity ratio of [Pt-ptc + Pt-dpp double pRNAi]/[normal] <0.6 were categorized as positive. The expressions of most, not all, of the transcripts related to the positive array spots were examined in embryos by whole-mount in situ hybridization. Some of the stained embryos showed distinct patterns of gene expression. The data presented may be useful for characterizing the mechanisms of embryonic patterning in spider embryos.
RESUMEN
The common house spider Parasteatoda tepidariorum, belonging to the Chelicerata in the phylum Arthropoda, has emerged as an experimental system for studying mechanisms of development from an evolutionary standpoint. In this article, we review the distinct characteristics of P. tepidariorum, the major research questions relevant to this organism, and the available key methods and resources. P. tepidariorum has a relatively short lifecycle and, once mated, periodically lays eggs. The morphogenetic field of the P. tepidariorum embryo is cellular from an early stage and exhibits stepwise symmetry-breaking events and stripe-forming processes that are associated with body axes formation and segmentation, respectively, before reaching the arthropod phylotypic stage. Self-regulatory capabilities of the embryonic field are a prominent feature in P. tepidariorum. The mechanisms and logic underlying the evolvability of heritable patterning systems at the phylum level could be one of the major avenues of research investigated using this animal. The sequenced genome reveals whole genome duplication (WGD) within chelicerates, which offers an invertebrate platform for investigating the potential roles of WGD in animal diversification and evolution. The development and evolution of lineage-specific organs, including the book lungs and the union of spinnerets and silk glands, are attractive subjects of study. Studies using P. tepidariorum can benefit from the use of parental RNA interference, microinjection applications (including cell labeling and embryonic RNA interference), multicolor fluorescence in situ hybridization, and laser ablation as well as rich genomic and transcriptomic resources. These techniques enable functional gene discoveries and the uncovering of cellular and molecular insights.