Balanced callose and cellulose biosynthesis in Arabidopsis quorum-sensing signaling and pattern-triggered immunity.

The plant cell wall (CW) is one of the most important physical barriers that phytopathogens must conquer to invade their hosts. This barrier is a dynamic structure that responds to pathogen infection through a complex network of immune receptors, together with CW-synthesizing and CW-degrading enzymes. Callose deposition in the primary CW is a well-known physical response to pathogen infection. Notably, callose and cellulose biosynthesis share an initial substrate, UDP-glucose, which is the main load-bearing component of the CW. However, how these 2 critical biosynthetic processes are balanced during plant-pathogen interactions remains unclear. Here, using 2 different pathogen-derived molecules, bacterial flagellin (flg22) and the diffusible signal factor (DSF) produced by Xanthomonas campestris pv. campestris, we show a negative correlation between cellulose and callose biosynthesis in Arabidopsis (Arabidopsis thaliana). By quantifying the abundance of callose and cellulose under DSF or flg22 elicitation and characterizing the dynamics of the enzymes involved in the biosynthesis and degradation of these 2 polymers, we show that the balance of these 2 CW components is mediated by the activity of a ß-1,3-glucanase (BG2). Our data demonstrate balanced cellulose and callose biosynthesis during plant immune responses.

Controllable self-cleaning FET self-assembled RNA-cleaving DNAzyme based DNA nanotree for culture-free Staphylococcus aureus detection.

Staphylococcus aureus (SA) poses a serious risk to human and animal health, necessitating a low-cost and high-performance analytical platform for point-of-care diagnostics. Cellulose paper-based field-effect transistors (FETs) with RNA-cleaving DNAzymes (RCDs) can fulfill the low-cost requirements, however, its high hydrophilicity and lipophilicity hinder biochemical modification and result in low sensitivity, poor mechanical stability and poor fouling performance. Herein, we proposed a controllable self-cleaning FET to simplify biochemical modification and improve mechanical stability and antifouling performance. Then, we constructed an RCD-based DNA nanotree to significantly enhance the sensitivity for SA detection. For controllable self-cleaning FET, 1 H,1 H,2 H,2 H-perfluorodecyltrimethoxysilane based-polymeric nanoparticles were synthesized to decorate cellulose paper and whole carbon nanofilm wires. O2 plasma was applied to regulate to reduce fluorocarbon chain density, and then control the hydrophobic-oleophobic property in sensitive areas. Because negatively charged DNA affected the sensitivity of semiconducting FETs, three Y-shaped branches with low-cost were designed and applied to synthesize an RCD-based DNA-Nanotree based on similar DNA-origami technology, which further improved the sensitivity. The trunk of DNA-Nanotree was composed of RCD, and the canopy was self-assembled using multiple Y-shaped branches. The controllable self-cleaning FET biosensor was applied for SA detection without cultivation, which had a wide linear range from 1 to 105 CFU/mL and could detect a low value of 1 CFU/mL.

Embosphere microspheres size for bronchial artery embolization in patients with hemoptysis caused by bronchiectasis: a retrospective comparative analysis of 500-750 versus 700-900 µm microspheres.

BACKGROUND: Bronchial arterial embolization (BAE) has been accepted as an effective treatment for bronchiectasis-related hemoptysis. However, rare clinical trials compare different sizes of specific embolic agents. This study aims to evaluate whether different Embosphere microsphere sizes change the outcome of BAE. METHODS: A retrospective review was conducted on consecutive patients with bronchiectatic hemoptysis who were scheduled to undergo BAE treatment during a period from January 2018 to December 2022. The patients received BAE using microspheres of different sizes: group A patients were treated with 500-750 µm microspheres, and group B patients were treated with 700-900 µm microspheres. The cost of embolic microspheres (Chinese Yuan, CNY), duration of hospitalization, complications, and hemoptysis-free survival were compared between patients in group A and those in group B. A Cox proportional hazards regression model was used to identify predictors of recurrent hemoptysis. RESULTS: Median follow-up was 30.2 months (range, 20.3-56.5 months). The final analysis included a total of 112 patients (49-77 years of age; 45 men). The patients were divided into two groups: group A (N = 68), which received 500-750 µm Embosphere microspheres, and group B (N = 44), which received 700-900 µm Embosphere microspheres. Except for the cost of embolic microspheres(group A,5314.8 + 1301.5 CNY; group B, 3644.5 + 1192.3 CNY; p = 0.042), there were no statistically significant differences in duration of hospitalization (group A,7.2 + 1.4 days; group B, 8 + 2.4days; p = 0.550), hemoptysis-free survival (group A, 1-year, 2-year, 3-year, 85.9%, 75.8%, 62.9%; group B, 1-year, 2-year, 3-year, 88.4%, 81.2%,59.4%;P = 0.060), and complications(group A,26.5%; group B, 38.6%; p = 0.175) between the two groups. No major complications were observed. The multivariate analysis results revealed that the presence of cystic bronchiectasis (OR 1.61, 95% CI 1.12-2.83; P = 0.001) and systemic arterial-pulmonary shunts (SPSs) (OR 1.52, 95% CI 1.10-2.72; P = 0.028) were independent risk factors for recurrent bleeding. CONCLUSIONS: For the treatment of BAE in patients with bronchiectasis-related hemoptysis, 500-750 µm diameter Embosphere microspheres have a similar efficacy and safety profile compared to 700-900 µm diameter Embosphere microspheres, especially for those without SPSs or cystic bronchiectasis. Furthermore, the utilization of large-sized (700-900 µm) Embosphere microspheres is associated with the reduced cost of an embolic agent.

Membrane-enclosed Pseudomonas quinolone signal attenuates bacterial virulence by interfering with quorum sensing.

Outer membrane vesicle (OMV)-delivered Pseudomonas quinolone signal (PQS) plays a critical role in cell-cell communication in Pseudomonas aeruginosa. However, the functions and mechanisms of membrane-enclosed PQS in interspecies communication in microbial communities are not clear. Here, we demonstrate that PQS delivered by both OMVs from P. aeruginosa and liposome reduces the competitiveness of Burkholderia cenocepacia, which usually shares the same niche in the lungs of cystic fibrosis patients, by interfering with quorum sensing (QS) in B. cenocepacia through the LysR-type regulator ShvR. Intriguingly, we found that ShvR regulates the production of the QS signals cis-2-dodecenoic acid (BDSF) and N-acyl homoserine lactone (AHL) by directly binding to the promoters of signal synthase-encoding genes. Perception of PQS influences the regulatory activity of ShvR and thus ultimately reduces QS signal production and virulence in B. cenocepacia. Our findings provide insights into the interspecies communication mediated by the membrane-enclosed QS signal among bacterial species residing in the same microbial community.IMPORTANCEQuorum sensing (QS) is a ubiquitous cell-to-cell communication mechanism. Previous studies showed that Burkholderia cenocepacia mainly employs cis-2-dodecenoic acid (BDSF) and N-acyl homoserine lactone (AHL) QS systems to regulate biological functions and virulence. Here, we demonstrate that Pseudomonas quinolone signal (PQS) delivered by outer membrane vesicles from Pseudomonas aeruginosa or liposome attenuates B. cenocepacia virulence by targeting the LysR-type regulator ShvR, which regulates the production of the QS signals BDSF and AHL in B. cenocepacia. Our results not only suggest the important roles of membrane-enclosed PQS in interspecies and interkingdom communications but also provide a new perspective on the use of functional nanocarriers loaded with QS inhibitors for treating pathogen infections.

Superhydrophobic Paper-Based Microfluidic Field-Effect Transistor Biosensor Functionalized with Semiconducting Single-Walled Carbon Nanotube and DNAzyme for Hypocalcemia Diagnosis.

Hypocalcemia is caused by a sharp decline in blood calcium concentration after dairy cow calving, which can lead to various diseases or even death. It is necessary to develop an inexpensive, easy-to-operate, reliable sensor to diagnose hypocalcemia. The cellulose-paper-based microfluidic field-effect biosensor is promising for point-of-care, but it has poor mechanical strength and a short service life after exposure to an aqueous solution. Octadecyltrichlorosilane (OTS), as a popular organosilane derivative, can improve the hydrophobicity of cellulose paper to overcome the shortage of cellulose paper. In this work, OTS was used to produce the superhydrophobic cellulose paper that enhances the mechanical strength and short service life of MFB, and a microfluidic field-effect biosensor (MFB) with semiconducting single-walled carbon nanotubes (SWNTs) and DNAzyme was then developed for the Ca2+ determination. Pyrene carboxylic acid (PCA) attached to SWNTs through a non-covalent π-π stacking interaction provided a carboxyl group that can bond with an amino group of DNAzyme. Two DNAzymes with different sensitivities were designed by changing the sequence length and cleavage site, which were functionalized with SPFET/SWNTs-PCA to form Dual-MFB, decreasing the interference of impurities in cow blood. After optimizing the detecting parameters, Dual-MFB could determine the Ca2+ concentration in the range of 25 µM to 5 mM, with a detection limit of 10.7 µM. The proposed Dual-MFB was applied to measure Ca2+ concentration in cow blood, which provided a new method to diagnose hypocalcemia after dairy cow calving.

[Analysis of a pedigree with autosomal dominant intermediate Charcot-Marie-Tooth disease type E and nephropathy].

OBJECTIVE: To explore phenotypic and mutational characteristics of a pedigree affected with autosomal dominant Charcot-Marie-Tooth disease (CMT) and nephropathy. METHODS: Clinical data of the proband and his family members was collected. Electrophysiology, renal biopsy and next-generation sequencing were carried out for the proband. RESULTS: The proband presented with distal lower limb weakness and proteinuria in childhood. His mother and brother had similar symptoms. Electrophysiological test of the proband revealed demyelination and axonal changes in both motor and sensory nerves. Renal biopsy suggested focal segmental glomerulosclerosis. Genetic testing revealed a heterozygous c.341G>A (p.G114D) mutation in exon 2 of the INF2 gene. CONCLUSION: The phenotypic feature of the pedigree is autosomal dominant intermediate CMT and focal segmental glomerulosclerosis, which may be attributed to the c.341G>A mutation of the INF2 gene.

Antimicrobial Activity and Cell Selectivity of Synthetic and Biosynthetic Cationic Polymers.

The mammalian and microbial cell selectivity of synthetic and biosynthetic cationic polymers has been investigated. Among the polymers with peptide backbones, polymers containing amino side chains display greater antimicrobial activity than those with guanidine side chains, whereas ethylenimines display superior activity over allylamines. The biosynthetic polymer ε-polylysine (εPL) is noncytotoxic to primary human dermal fibroblasts at concentrations of up to 2,000 µg/ml, suggesting that the presence of an isopeptide backbone has greater cell selectivity than the presence of α-peptide backbones. Both εPL and linear polyethylenimine (LPEI) exhibit bactericidal properties by depolarizing the cytoplasmic membrane and disrupt preformed biofilms. εPL displays broad-spectrum antimicrobial properties against antibiotic-resistant Gram-negative and Gram-positive strains and fungi. εPL elicits rapid bactericidal activity against both Gram-negative and Gram-positive bacteria, and its biocompatibility index is superior to those of cationic antiseptic agents and LPEI. εPL does not interfere with the wound closure of injured rabbit corneas. In a rabbit model of bacterial keratitis, the topical application of εPL (0.3%, wt/vol) decreases the bacterial burden and severity of infections caused by Pseudomonas aeruginosa and Staphylococcus aureus strains. In vivo imaging studies confirm that εPL-treated corneas appeared transparent and nonedematous compared to untreated infected corneas. Taken together, our results highlight the potential of εPL in resolving topical microbial infections.

A pre-formulation study of a polymeric solid dispersion of paclitaxel prepared using a quasi-emulsion solvent diffusion method to improve the oral bioavailability in rats.

OBJECTIVE: To preliminarily develop a surfactant-free, polymeric solid dispersion (PSD) of paclitaxel suitable for oral administration. METHODS: A co-solvent quench method was applied to screen the proper polymer matrix of the PSD which were prepared in a liquid system using a quasi-emulsion solvent diffusion method (QESDM). Three dissolution experiments and two in vivo tests in rats were used to explain the differences among the formulations. RESULTS: The theoretical solubility ratio of amorphous/crystalline PTX was 92.6 (37 °C). Hydroxypropyl methylcellulose acetate succinate (HPMCAS) was chosen as the polymer carrier of the PSD and a porous silicon dioxide [called white carbon black (WCB)] was selectable to be used to further adjust the dissolution rate. The absolute oral bioavailability (AOB, 20 mg/kg) of the three formulas [HPMCAS/paclitaxel/WCB = 4/1/0 (F1), 8/1/0 (F2) and 4/1/4 (F3), w/w/w] were 11.8, 13.6 and 25.6%, respectively. The AOB of F3 is nearly seven times higher than that (3.8%) of paclitaxel material (a control). The advantage of higher HPMCAS/paclitaxel ratio of F2 in a dissolution test was not reflected in the first in vivo test due to the relatively higher dose of polymer which could not be effectively dissolved under the limitation of intestinal environment. This was deduced from the dissolution tests and was finally validated when the oral dose of PTX (and thus polymer) was reduced. The relevant AOBs (10 mg/kg) were 10.4, 20.8 and 19.6%, respectively. CONCLUSION: The PSD is a promising formulation strategy and the QESDM is a practical preparation method to implement such formulation design.

Sorption behaviors of petroleum on micro-sized polyethylene aging for different time in seawater.

Microplastics (MPs; <5 mm) and oil pollution have been receiving global attention. To date, the adsorption mechanism of petroleum by MPs is largely unknown. This study investigated the adsorption of petroleum on micro-sized polyethylene (mPE) undergoing aging (days 0, 15, 30, 90 and 180). The petroleum adsorption capacity of mPE was further assessed at varying pH (2, 5, 7.32, 10 and 12), temperature (4, 15, 25, 45 and 65 °C) and in presence of coexisting pollutants (Cu, bisphenol A (BPA) and petroleum). The results indicated that the adsorption capacity of mPE increased with the prolonged aging time and smaller-sized particles, while the adsorption capacity of the 550 and 165 µm mPE undergoing aging increased by 12.7%-50.9% and 22.1%-63.9%, respectively. The adsorption kinetics and isotherm model of mPE on petroleum were well fitted by pseudo-second order, intraparticle diffusion, Freundlich and Langmuir models, showing the sorption behavior was controlled by the diffusion of pores, liquid film diffusion, and surface adsorption. The petroleum adsorption capacity of mPE was predominant affected by surface roughness, specific surface area, hydrophobicity, oxidation functional groups, adsorption sites, hydrogen bonds, while zeta potential and crystallinity may not be the crucial factors. Likewise, temperature and pH may influence the characteristics of petroleum, and further result in a decreasing adsorption capacity of mPE to petroleum. The highest adsorption capacity of mPE to petroleum was reached at pH 7.32 and 25 °C. The coexisting Cu, BPA and petroleum competed for adsorption sites on the surface of mPE. These findings could fundamentally provide new insights for environmental risk assessment of MPs, particularly for the specific location like harbor which is commonly rich in MPs and petroleum simultaneously.

Biomimetic porous scaffolds containing decellularized small intestinal submucosa and Sr2+/Fe3+co-doped hydroxyapatite accelerate angiogenesis/osteogenesis for bone regeneration.

The design of bone scaffolds is predominately aimed to well reproduce the natural bony environment by imitating the architecture/composition of host bone. Such biomimetic biomaterials are gaining increasing attention and acknowledged quite promising for bone tissue engineering. Herein, novel biomimetic bone scaffolds containing decellularized small intestinal submucosa matrix (SIS-ECM) and Sr2+/Fe3+co-doped hydroxyapatite (SrFeHA) are fabricated for the first time by the sophisticated self-assembled mineralization procedure, followed by cross-linking and lyophilization post-treatments. The results indicate the constructed SIS/SrFeHA scaffolds are characterized by highly porous structures, rough microsurface and improved mechanical strength, as well as efficient releasing of bioactive Sr2+/Fe3+and ECM components. These favorable physico-chemical properties endow SIS/SrFeHA scaffolds with an architectural/componential biomimetic bony environment which appears to be highly beneficial for inducing angiogenesis/osteogenesis bothin vitroandin vivo. In particular, the cellular functionality and bioactivity of endotheliocytes/osteoblasts are significantly enhanced by SIS/SrFeHA scaffolds, and the cranial defects model further verifies the potent ability of SIS/SrFeHA to acceleratein vivovascularization and bone regeneration following implantation. In this view these results highlight the considerable angiogenesis/osteogenesis potential of biomimetic porous SIS/SrFeHA scaffolds for inducing bone regeneration and thus may afford a new promising alternative for bone tissue engineering.

Occurrence and spatial distribution of microplastics, and their correlation with petroleum in coastal waters of Hainan Island, China.

In this study, the distribution, abundance, morphology, and composition of microplastics (MPs) in surface seawater and sediment of Hainan Island were systematically investigated. Seawater and sediment samples were collected from six functional zones, including harbor, industrial district, sparsely populated area, tourist area, residential area, and aquaculture area. The abundance of MPs in seawater was 0.46-19.32 items/L, with an average of 2.59 ± 0.43 items/L, which were similar to those detected in the South China Sea (e.g., Nansha (1.25-3.20 items/L) and Xisha (2.57 ± 1.78 items/L)). The highest level was detected in Qinglan Bay Estuary, and the lowest was in Sanya West Island. The abundance of MPs in sediment was 41.18-750.63 items/kg, with an average of 372.47 ± 62.10 items/kg; the highest concentration was detected at Tanmen Port, and the lowest was in Lingao sea area. It was detected that the MPs with smaller size exhibited a higher concentration in seawater. MPs were commonly black and white, and predominantly linear and fragmented in shape. Polyethylene terephthalate (PET) was the dominant polymer, which might be derived from laundry wastewater. The petroleum concentration was 0.02-0.21 mg/L in the investigated area, with harbors being the most severely polluted areas. Furthermore, this study also found that MPs pollution was positively correlated with petroleum in seawater, indicating similarities between MPs and petroleum-based sources of pollution. This study identifies the contamination and characteristics of MPs and their correlation with petroleum in Hainan Island, the biggest island in the South China Sea, providing important data for further research on protecting marine ecosystems.

2,3,5,4'-Tetrahydroxystilbene-2-O-ß-glucoside Attenuates Reactive Oxygen Species-Dependent Inflammation and Apoptosis in Porphyromonas gingivalis-Infected Brain Endothelial Cells.

We recently reported that the periodontopathic bacteria Porphyromonas gingivalis (P. gingivalis) initiates an inflammatory cascade that disrupts the balance of reactive oxygen species (ROS), resulting in apoptotic cell death in brain endothelial cells. An extract from Polygonum multiflorum Thunb., 2,3,5,4'-Tetrahydroxystilbene-2-O-ß-glucoside (THSG) has been well-reported to diminish the inflammation in many disease models. However, the effects of THSG in the area of the brain-oral axis is unknown. In this study, we examined the effects of THSG in P. gingivalis-stimulated inflammatory response and apoptotic cell death in brain endothelial cells. THSG treatment remarkably lessened the upregulation of IL-1ß and TNF-α proteins in bEnd.3 cells infected with P. gingivalis. Treatment of THSG further ameliorated brain endothelial cell death, including apoptosis caused by P. gingivalis. Moreover, the present study showed that the inhibitory effects on NF-κB p65 and antiapoptotic properties of THSG is through inhibiting the ROS pathway. Importantly, the ROS inhibitory potency of THSG is similar to a ROS scavenger N-Acetyl-L-Cysteine (NAC) and NADPH oxidase inhibitor apocynin. Furthermore, the protective effect of THSG from P. gingivalis infection was further confirmed in primary mouse brain endothelial cells. Taken together, this study indicates that THSG attenuates an ROS-dependent inflammatory response and cell apoptosis in P. gingivalis-infected brain endothelial cells. Our results also suggest that THSG could be a potential herbal medicine to prevent the risk of developing cerebrovascular diseases from infection of periodontal bacteria.

Selection of hyperadherent mutants in Pseudomonas putida biofilms.

A number of genetic determinants required for bacterial colonization of solid surfaces and biofilm formation have been identified in different micro-organisms. There are fewer accounts of mutations that favour the transition to a sessile mode of life. Here we report the isolation of random transposon Pseudomonas putida KT2440 mutants showing increased biofilm formation, and the detailed characterization of one of them. This mutant exhibits a complex phenotype, including altered colony morphology, increased production of extracellular polymeric substances and enhanced swarming motility, along with the formation of denser and more complex biofilms than the parental strain. Sequence analysis revealed that the pleiotropic phenotype exhibited by the mutant resulted from the accumulation of two mutations: a transposon insertion, which disrupted a predicted outer membrane lipoprotein, and a point mutation in lapG, a gene involved in the turnover of the large adhesin LapA. The contribution of each alteration to the phenotype and the possibility that prolonged sessile growth results in the selection of hyperadherent mutants are discussed.

Bioactivity study of the titanium plates treated with microarc oxidation and alkali.

Microarc oxidation (MAO) and alkali treatment was used to modify the surface of titanium, which prepared different microstructure and nanostructure TiO2-based coating on titanium. The samples were analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and contact angle measuring instrument. The sample's surface treated by MAO process was microporous structure and looks like a crate. In vitro bioactivity experiment indicated that the hydroxyapatite precipitates was as squama and grew perpendicularly on the sample's surface. In vitro cell culture and MTT assay the MAO-NaOH samples showed distinct proliferation levels compared to the MAO samples. It has no toxicity to the growth of MSC cell and had better biocompatibility. According to the calculation of surface energy, that better hydrophilicity of materials will induce the more growth of hydroxyapatite.

The fabrication and property of hydrophilic and hydrophobic double functional bionic chitosan film.

A new kind of hydrophobic bionic chitosan film was fabricated by simulating the surface structure of lotus leaf. The titanium oxide nanotube array was used as templates. Scanning electron microscopy (SEM) images show that one side of this films have nano-scale rough surface with spherical protrusions alike the surface of lotus leaf. The diameter of the protrusions is about 100 nm, which is equal to diameter of the titanium oxide nanotube. The water contact angle of chitosan films is up to 120 degrees and it is hydrophobic. The other side of the film is flat and the contact angle is 70 degrees. That indicated that the hydrophilism of natural materials is connected with the surface structures. The double functional chitosan films, one side is hydrophilic, the other is hydrophobic, can be made by an easy method. This method is non-toxic and clean. The double functional chitosan film will improve the application of chitosan films in medicine.

The role of natural polymers in bone tissue engineering.

Bone is a dynamic self-healing organ and a continuous remodeling ensures the restoration of the bone structure and function over time. However, bone remodeling is not able to repair large traumatic injuries. Therefore, surgical interventions and bone substitutes are required. The aim of bone tissue engineering is to repair and regenerate tissues and engineered a bone graft as a bone substitute. To met this goal, several natural or synthetic polymers have been used to develop a biocompatible and biodegradable polymeric construct. Among the polymers, natural polymers have higher biocompatibility, excellent biodegradability, and no toxicity. So far, collagen, chitosan, gelatin, silk fibroin, alginate, cellulose, and starch, alone or in combination, have been widely used in bone tissue engineering. These polymers have been used as scaffolds, hydrogels, and micro-nanospheres. The functionalization of the polymer with growth factors and bioactive glasses increases the potential use of polymers for bone regeneration. As bone is a dynamic highly vascularized tissue, the vascularization of the polymeric scaffolds is vital for successful bone regeneration. Several in vivo and in vitro strategies have been used to vascularize the polymeric scaffolds. In this review, the application of the most commonly used natural polymers is discussed.

Femtosecond laser-induced periodic grooves and nanopore clusters make a synergistic effect on osteogenic differentiation.

Polyether-ether-ketone (PEEK) materials have good biocompatibility, excellent corrosion resistance, chemical stability and an elastic modulus close to that of natural bone. However, due to its biological inertness, PEEK may affect osteogenic differentiation and leads to osseointegration failure, though PEEK is expected to improve osseointegration. In this work, by changing the power of femtosecond laser, micro-grooves are made on the PEEK surface. As observed by scanning electron microscopy, the trench has a periodic structure, the micro shape is neat, and the trench is also covered with nanometer-level pore clusters. In the in vitro culture experiments, through the proliferation experiment of mouse bone marrow mesenchymalstem cells (mBMSCs), cell viability analysis and alkaline phosphatase activity analysis, it is proven that after femtosecond laser treatment of the PEEK surface, the micro-grooves on the surface and the nanopore clusters due to laser energy ablation can produce a synergistic effect, enhancing the osteogenic differentiation ability of cells, and improving the bone integration ability of PEEK materials.

Porphyromonas gingivalis Induces Proinflammatory Cytokine Expression Leading to Apoptotic Death through the Oxidative Stress/NF-κB Pathway in Brain Endothelial Cells.

Porphyromonas gingivalis, a periodontal pathogen, has been proposed to cause blood vessel injury leading to cerebrovascular diseases such as stroke. Brain endothelial cells compose the blood-brain barrier that protects homeostasis of the central nervous system. However, whether P. gingivalis causes the death of endothelial cells and the underlying mechanisms remain unclear. This study aimed to investigate the impact and regulatory mechanisms of P. gingivalis infection in brain endothelial cells. We used bEnd.3 cells and primary mouse endothelial cells to assess the effects of P. gingivalis on endothelial cells. Our results showed that infection with live P. gingivalis, unlike heat-killed P. gingivalis, triggers brain endothelial cell death by inducing cell apoptosis. Moreover, P. gingivalis infection increased intracellular reactive oxygen species (ROS) production, activated NF-κB, and up-regulated the expression of IL-1ß and TNF-α. Furthermore, N-acetyl-L-cysteine (NAC), a most frequently used antioxidant, treatment significantly reduced P. gingivalis-induced cell apoptosis and brain endothelial cell death. The enhancement of ROS production, NF-κB p65 activation, and proinflammatory cytokine expression was also attenuated by NAC treatment. The impact of P. gingivalis on brain endothelial cells was also confirmed using adult primary mouse brain endothelial cells (MBECs). In summary, our results showed that P. gingivalis up-regulates IL-1ß and TNF-α protein expression, which consequently causes cell death of brain endothelial cells through the ROS/NF-κB pathway. Our results, together with the results of previous case-control studies and epidemiologic reports, strongly support the hypothesis that periodontal infection increases the risk of developing cerebrovascular disease.

Formin nanoclustering-mediated actin assembly during plant flagellin and DSF signaling.

Plants respond to bacterial infection acutely with actin remodeling during plant immune responses. The mechanisms by which bacterial virulence factors (VFs) modulate plant actin polymerization remain enigmatic. Here, we show that plant-type-I formin serves as the molecular sensor for actin remodeling in response to two bacterial VFs: Xanthomonas campestris pv. campestris (Xcc) diffusible signal factor (DSF), and pathogen-associated molecular pattern (PAMP) flagellin in pattern-triggered immunity (PTI). Both VFs regulate actin assembly by tuning the clustering and nucleation activity of formin on the plasma membrane (PM) at the nano-sized scale. By being integrated within the cell-wall-PM-actin cytoskeleton (CW-PM-AC) continuum, the dynamic behavior and function of formins are highly dependent on each scaffold layer's composition within the CW-PM-AC continuum during both DSF and PTI signaling. Our results reveal a central mechanism for rapid actin remodeling during plant-bacteria interactions, in which bacterial signaling molecules fine tune plant formin nanoclustering in a host mechanical-structure-dependent manner.

Surface modified small intestinal submucosa membrane manipulates sequential immunomodulation coupled with enhanced angio- and osteogenesis towards ameliorative guided bone regeneration.

Constructing bioactive guided bone regeneration (GBR) membranes that possess biological multifunctionality is becoming increasingly attractive and promising to meet higher requirements for bone healing. Given the biological responses following implantation, GBR process originates from an early inflammation-driven reaction adjacent to implanted membranes surface. However, to date there is relatively little attention paid to the critical immunoregulatory functions in traditionally designed GBR membranes. Herein, for the first time, we manipulate immunomodulatory properties of the widely-used native small intestinal submucosa (SIS) membrane by incorporating strontium-substituted nanohydroxyapatite coatings and/or IFN-γ to its surface. In vitro results reveal the obtained novel membrane SIS/SrHA/IFN-γ not only promote functions of endothelial cells and osteoblasts directly, but also energetically mediate a sequential M1-M2 macrophages transition to concurrently facilitate angiogenesis and osteogenesis. Moreover, in vivo outcomes of subcutaneous implantation and cranial defects repair further confirm its superior capacity to promote vascularization and in situ bone regeneration than pristine SIS through immunomodulation. These results demonstrate a sequential immunomodulatory strategy renders modified SIS membranes acting as a robust immunomodulator rather than a traditional barrier to significantly ameliorate in vivo GBR outcomes and hence provide important implications that may facilitate concerns on immunomodulatory properties for future GBR developments.