Tissue-specific extracellular matrix plays an important role in promoting tissue regeneration and repair. We hypothesized that decellularized annular fibrosus matrix may be an appropriate scaffold for annular fibrosus tissue engineering. We aimed to determine the optimal decellularization method suitable for annular fibrosus. Annular fibrosus tissue was treated with 3 different protocols with Triton X-100, sodium dodecyl sulfate (SDS) and trypsin. After the decellularization process, we examined cell removal and preservation of the matrix components, microstructure and mechanical function with the treatments to determine which method is more efficient. All 3 protocols achieved decellularization; however, SDS or trypsin disturbed the structure of the annular fibrosus. All protocols maintained collagen content, but glycosaminoglycan content was lost to different degrees, with the highest content with TritonX-100 treatment. Furthermore, SDS decreased the tensile mechanical property of annular fibrosus as compared with the other 2 protocols. MTT assay revealed that the decellularized annular fibrosus was not cytotoxic. Annular fibrosus cells seeded into the scaffold showed good viability. The Triton X-100–treated annular fibrosus retained major extracellular matrix components after thorough cell removal and preserved the concentric lamellar structure and tensile mechanical properties. As well, it possessed favorable biocompatibility, so it may be a suitable candidate as a scaffold for annular fibrosus tissue engineering.
Background and Purpose Inflammatory injury plays a critical role in intracerebral hemorrhage (ICH)-induced secondary brain injury. Recently, Dopamine D2 receptor (DRD2) is identified an important component controlling innate immunity and inflammatory response in central nervous system and αB-crystallin (CRYAB) is a potent negative regulator on inflammatory pathways. Here, we sought to investigate the role of DRD2 on neuroinflammation after experimental ICH, and the potential mechanism mediated by CRYAB. Methods Two hundred and twenty-four (224) male CD-1 mice were subjected to intrastriatal infusion of bacterial collagenase or autologous blood. Two DRD2 agonists Quinpirole and Ropinirole were administrated by daily intraperitoneal injection starting at 1 hour post-ICH. DRD2 and CRYAB in vivo knockdown was performed 48 hour before ICH insult. Behavioral deficits and brain water content, western blots, immunofluorescence staining, co-immunoprecipitation assay and proteome cytokine array were evaluated. Results Endogenous DRD2 and CRYAB expression were increased after ICH. DRD2 knockdown aggravated the neurobehavioral deficits and the pronounced cytokines expression. DRD2 activation by Quinpirole and Ropinirole ameliorated neurological outcome, brain edema, IL-1β and MCP-1 expression, as well as microglia/macrophages activation in the perihematomal region. These effects were abolished by pretreated with CRYAB siRNAs. Quinpirole enhanced cytoplasmic binding activity between CRYAB and NF-κB, and decreased nuclear NF-κB expression. Similar therapeutic benefits were observed using autologous blood injection model and intranasal delivery of Quinpirole. Conclusions DRD2 may have anti-inflammatory effects after ICH. DRD2 agonists inhibited neuroinflammation and attenuated brain injury after ICH, which is probably mediated by CRYAB and enhanced cytoplasmic binding activity with NF-κB.
Obligatory blood-triggered reproductive strategy is an evolutionary adaptation of mosquitoes for rapid egg development. It contributes to the vectorial capacity of these insects. Therefore, understanding the molecular mechanisms underlying reproductive processes is of particular importance. Here, we report that microRNA-309 (miR-309) plays a critical role in mosquito reproduction. A spatiotemporal expression profile of miR-309 displayed its blood feeding-dependent onset and ovary-specific manifestation in female Aedes aegypti mosquitoes. Antagomir silencing of miR-309 impaired ovarian development and resulted in nonsynchronized follicle growth. Furthermore, the genetic disruption of miR-309 by CRISPR/Cas9 system led to the developmental failure of primary follicle formation. Examination of genomic responses to miR-309 depletion revealed that several pathways associated with ovarian development are down-regulated. Comparative analysis of genes obtained from the high-throughput RNA sequencing of ovarian tissue from the miR-309 antagomirsilenced mosquitoes with those from the in silico computation target prediction identified that the gene-encoding SIX homeobox 4 protein (SIX4) is a putative target of miR-309. Reporter assay and RNA immunoprecipitation confirmed that SIX4 is a direct target of miR-309. RNA interference of SIX4 was able to rescue phenotypic manifestations caused by miR-309 depletion. Thus, miR-309 plays a critical role in mosquito reproduction by targeting SIX4 in the ovary and serves as a regulatory switch permitting a stage-specific degradation of the ovarian SIX4 mRNA. In turn, this microRNA (miRNA)-targeted degradation is required for appropriate initiation of a blood feeding-triggered phase of ovarian development, highlighting involvement of this miRNA in mosquito reproduction.Homeobox protein gene | microRNA | CRISPR/Cas9 | ovary | fast evolution T ransmission of mosquito-borne diseases brings enormous human suffering, with more than 1 million deaths worldwide annually. The yellow fever mosquito Aedes aegypti has reemerged as one of the most dangerous vectors of human diseases, transmitting Dengue fever, Yellow fever, Chikungunya, and Zika virus (1-4). Because of the lack of effective vaccines and increasing drug resistance in pathogens, biological control is considered one of the most promising strategies for preventing disease transmission. In particular, female hematophagous mosquitoes rely on acquisition of blood to initiate a series of physiological events promoting egg development (5, 6). Therefore, understanding the molecular mechanisms underlying ovarian activation is of great significance for the development of effective approaches to control mosquito-borne diseases (7,8).MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression at the posttranscriptional level through translational repression or mRNA decay (9). Hence, miRNAs play significant roles in governing multiple functions in animals and plants via integrating sophisticated miRNA-mRNA regulatory networks (10, 11...
Background and Purpose Norrin and its receptor Frizzled 4 have important roles in the blood-brain barrier (BBB) development. This study is to investigate a potential role and mechanism of Norrin/Frizzled 4 on protecting BBB integrity after subarachnoid hemorrhage (SAH). Methods One hundred and seventy-eight male Sprague-Dawley rats were used. SAH model was induced by endovascular perforation. Frizzled 4 small interfering RNA (siRNA) was injected intracerebroventricularly 48 hours before SAH. Norrin was administrated intracerebroventricularly 3 hours after SAH. SAH grade, neurologic scores, brain water content, Evans blue extravasation, western blots and immunofluorescence were employed to study the mechanisms of Norrin and its receptor regulation protein TSPAN12, as well as neurological outcome. Results Endogenous Norrin and TSPAN12 expression were increased after SAH, and Norrin was colocalizated with astrocytes marker GFAP in cortex. Exogenous Norrin treatment significantly alleviated neurobehavioral dysfunction, reduced brain water content and Evans blue extravasation, promoted β-catenin nuclear translocation and increased Occludin, VE-Cadherin and ZO-1 expressions. These effects were abolished by Frizzled 4 siRNA pretreated before SAH. Conclusions Norrin protected BBB integrity and improved neurological outcome after SAH, and the action of Norrin seemed mediated by Frizzled 4 receptor activation which promoted β-catenin nuclear translocation, which then enhanced Occludin, VE-Cadherin and ZO-1 expression. Norrin might have potential to protect BBB after SAH.
Inferences about the relationships between scores on selection tests and measures of job performance are often made on the basis of an assessment of the match between the content of the test and the content of the job. However, there is little evidence that these test-to-job comparisons have any bearing on the criterion-related validity of selection tests. The authors show that conclusions reached in analyses of cognitive tests-that content matching is largely irrelevant to criterion-related validity-can be generalized to most sets of selection tests (e.g., psychomotor and performance tests, interview ratings, biodata scores, knowledge tests, work sample tests) that are positively correlated with one another and with the criterion. When the universe of potential predictors shows positive manifold, almost all possible sets of test batteries will yield similar outcomes and show similar validities, regardless of whether the content of these tests matches the content of the job.
BackgroundAtrazine (2-chloro-4-ethytlamino-6-isopropylamine-1,3,5-triazine; ATR), is the most commonly applied broad-spectrum herbicide in the world. Unintentional overspray of ATR poses an immune function health hazard. The biomolecular mechanisms responsible for ATR-induced immunotoxicity, however, are little understood. This study presents on our investigation into the apoptosis of splenocytes in mice exposed to ATR as we explore possible immunotoxic mechanisms.MethodsOral doses of ATR were administered to BALB/C mice for 21 days. The histopathology, lymphocyte apoptosis and the expression of apoptosis-related proteins from the Fas/Fas ligand (FasL) apoptotic pathway were examined from spleen samples.ResultsMice administered ATR exhibited a significant decrease in spleen and thymus weight. Electron microscope histology of ultrathin sections of spleen revealed degenerative micromorphology indicative of apoptosis of splenocytes. Flow cytometry revealed that the percentage of apoptotic lymphocytes increased in a dose-dependent manner after ATR treatment. Western blots identified increased expression of Fas, FasL and active caspase-3 proteins in the treatment groups.ConclusionsATR is capable of inducing splenocytic apoptosis mediated by the Fas/FasL pathway in mice, which could be the potential mechanism underlying the immunotoxicity of ATR.
A 3-D scaffold that simulates the microenvironment in vivo for regenerating cartilage is ideal. In this study, we combined silk fibroin and decellularized cartilage extracellular matrix by temperature gradient-guided thermal-induced phase separation to produce composite scaffolds (S/D). Resulting scaffolds had remarkable mechanical properties and biomimeticstructure, for a suitable substrate for attachment and proliferation of adipose-derived stem cells (ADSCs). Moreover, transforming growth factor β3 (TGF-β3) loaded on scaffolds showed a controlled release profile and enhanced the chondrogenic differentiation of ADSCs during the 28-day culture. The S/D scaffold itself can provide a sustained release system without the introduction of other controlled release media, which has potential for commercial and clinical applications. The results of toluidine blue, Safranin O, and immunohistochemical staining and analysis of collagen II expression showed maintenance of a chondrogenic phenotype in all scaffolds after 28-day culture. The most obvious phenomenon was with the addition of TGF-β3. S/D composite scaffolds with sequential delivery of TGF-β3 may mimic the regenerative microenvironment to enhance the chondrogenic differentiation of ADSCs in vitro.
The evolution of TLR-mediated innate immunity is a fundamental question in immunology. Here, we report the characterization and functional analysis of four TLR members in the lophotrochozoans Crassostrea gigas (CgTLRs). All CgTLRs bear a conserved domain organization and have a close relationship with TLRs in ancient non-vertebrate chordates. In HEK293 cells, every CgTLR could constitutively activate NF-κB responsive reporter, but none of the PAMPs tested could stimulate CgTLR-activated NF-κB induction. Subcellular localization showed that CgTLR members have similar and dual distribution on late endosomes and plasma membranes. Moreover, CgTLRs and CgMyD88 mRNA show a consistent response to multiple PAMP challenges in oyster hemocytes. As CgTLR-mediated NF-κB activation is dependent on CgMyD88, we designed a blocking peptide for CgTLR signaling that would inhibit CgTLR-CgMyD88 dependent NF-κB activation. This was used to demonstrate that a Vibrio parahaemolyticus infection-induced enhancement of degranulation and increase of cytokines TNF mRNA in hemocytes, could be inhibited by blocking CgTLR signaling. In summary, our study characterized the primitive TLRs in the lophotrocozoan C . gigas and demonstrated a fundamental role of TLR signaling in infection-induced hemocyte activation. This provides further evidence for an ancient origin of TLR-mediated innate immunity.
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