Systematic identification and functional characterization of the CFEM proteins in fishscale bamboo rhombic-spot pathogen Neostagonosporella sichuanensis.

Fungal effectors play a crucial role in the interaction between pathogenic fungi and their hosts. These interactions directly influence the invasion and spread of pathogens, and the development of diseases. Common in fungal extracellular membrane (CFEM) effectors are closely associated with the pathogenicity, cell wall stability, and pathogenic processes of pathogenic fungi. The aim of this study was to investigate the role of CFEM proteins in Neostagonosporella sichuanensis in pathogen-host interactions. We retrieved 19 proteins containing CFEM structural domains from the genome of N. sichuanensis. By systematic analysis, five NsCFEM proteins had signal peptides but lacked transmembrane structural domains, and thus were considered as potential effectors. Among them, NsCFEM1 and NsCFEM2 were successfully cloned and their functions were further investigated. The validation results show that NsCFEM1 was localized in the cell membrane and nucleus, whereas NsCFEM2 was exclusively observed in the cell membrane. Both were identified as secreted proteins. Additionally, NsCFEM1 inhibited Bax-induced programmed cell death in Nicotiana benthamiana, whereas NsCFEM2 did not induce or inhibit this response. NsCFEM1 was implicated as a virulence factor that contributes to fungal growth, development, stress response, and pathogenicity. NsCFEM2 was implicated in maintenance of cell wall stability. This study lays a foundation for elucidating the role of CFEM proteins in the pathogen of fishscale bamboo rhombic-spot caused by N. sichuanensis. In particular, the functional studies of NsCFEM1 and NsCFEM2 revealed their potential roles in the interaction between N. sichuanensis and the host Phyllostachys heteroclada.

Extracellular vesicles encapsulated with caspase-1 inhibitor ameliorate experimental autoimmune myasthenia gravis through targeting macrophages.

Cysteinyl aspartate-specific proteinase-1 (caspase-1) is a multifunctional inflammatory mediator in many inflammation-related diseases. Previous studies show that caspase-1 inhibitors produce effective therapeutic outcomes in a rat model of myasthenia gravis. However, tissue toxicity and unwanted off-target effects are the major disadvantages limiting their clinical application as therapeutic agents. This study shows that dendritic cell-derived extracellular vesicles (EVs) loaded with a caspase-1 inhibitor (EVs-VX-765) are phagocytized mainly by macrophages, and caspase-1 is precisely expressed in macrophages. Furthermore, EVs-VX-765 demonstrates excellent therapeutic effects through a macrophage-dependent mechanism, and it notably inhibits the level of interleukin-1ß and subsequently inhibits Th17 response and germinal center (GC) reactions. In addition, EVs-VX-765 demonstrates better therapeutic effects than routine doses of VX-765, although drug loading is much lower than routine doses, consequently reducing tissue toxicity. In conclusion, this study's findings suggest that EV-mediated delivery of caspase-1 inhibitors is effective for treating myasthenia gravis and is promising for clinical applications.

Epstein-Barr virus: To be a trigger of autoimmune glial fibrillary acidic protein astrocytopathy?

BACKGROUND: Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy is a novel autoimmune disease of central nervous system (CNS). It is unclear whether Epstein-Barr virus (EBV) is related to autoimmune GFAP astrocytopathy. OBJECTIVE: To describe the clinical, laboratory, and imaging characteristics of patients with autoimmune GFAP astrocytopathy. METHODS: The clinical, laboratory, and imaging findings of patients are presented. The levels of GFAP in CSF were detected by ELISA. T and B cell subsets in CSF were detected by flow cytometry. GFAP-IgG in serum and cerebrospinal fluid (CSF) were tested by cell-based assay (CBA) and tissue-based assay (TBA). RESULTS: All three patients had fever, cognitive dysfunction, limb weakness, and positive GFAP-IgG with EBV infection in CSF. Enteric glia cells may involve in this disease. Typical imaging findings include the gadolinium enhancement of linear perivascular radial perpendicular to the ventricle, meningeal enhancement (especially in midbrain interpeduncal fossa), longitudinally extensive lesions involving spindle cords, and more T2/Flair-hyperintense lesions in the periventricular white matter at late stage. The patients had poor response to antiviral treatment and strong response to steroid pulse therapy. CONCLUSION: EBV could induce CNS autoimmune response in autoimmune GFAP astrocytopathy. The detection of GFAP-IgG and EBV may facilitate the early diagnosis in these patients.

Nigrospora musae Causing Taxus chinensis var. mairei stem blight in Sichuan, China.

Taxus chinensis var. mairei is the endemic, endangered, and first-class protected tree species in China. This species is considered as an important resource plant because it can produce Taxol which is an effective medicinal compound against various cancers (Zhang et al., 2010). Stem blight was observed in two plant nurseries in Ya'an (102°44'E,30°42'N), Sichuan province in April 2021. The symptoms first appeared as round brown spots on the stem. As the disease progressed, the damaged area gradually expanded into an oval or irregular shape, which was dark brown. About 800 square meters of planting area were investigated and the disease incidence was up to approximately 64.8%. Twenty obviously symptomatic stems which exhibited the same symptoms as above were collected from 5 different trees in the nursery. To isolate the pathogen, the symptom margin was cut into small blocks (5 x 5 mm), and the blocks were surface sterilized in 75% ethanol for 90 s and 3% NaClO solution for 60 s . Finally incubated on Potato Dextrose Agar (PDA) at 28℃ for 5 days. Ten pure cultures were isolated by transferring hyphal and the three strains (HDS06, HDS07 and HDS08) were selected as representative isolates for further study. Initially, colonies on the PDA of three isolates were white and cotton-like, and then gradually turned gray-black from the center. After 21 days, conidia were produced and were smooth-walled, single-celled, black, oblate, or spherical, measuring 9.3 to 13.6 × 10.1 to 14.5 µm in size (n = 50). Conidia were present at the tip of conidiophores on hyaline vesicles. These morphological features were generally consistent with those of N. musae (Wang et al., 2017). To validate the identification, DNA were extracted from the three isolates, followed by the amplification of transcribed spacer region of rDNA (ITS), the translation elongation factor EF-1 (TEF-1), and the Beta-tubulin (TUB2) sequences with the respective primer pairs ITS1/ITS4 (White et al., 1990), EF-728F/EF-986R (Vieira et al., 2014) and Bt2a/Bt2b (O'Donnell et al., 1997) .The sequences were deposited in GenBank with the accession numbers ON965533, OP028064, OP028068, OP060349, OP060353, OP060354, OP060350, OP060351 and OP060352, respectively. Phylogenetic analysis of combined ITS, TUB2, and TEF genes using the Mrbayes inference method showed that the three isolates clustered with Nigrospora musae as a distinct clade (Fig. 2). Combine with morphological characteristics and phylogenetic analysis, three isolates were identified as N. musae. 30 2-year-old healthy potted plants of T. chinensis were used for pathogenicity test. 25 of these plants were inoculated by injecting 10 µL of the conidia suspension (1 × 106 conidia/mL) into stems and then wrap around the seal to moisturize. The remaining 5 plants were injected with the same amount of sterilized distilled water as a control. Finally, all potted plants were placed in a greenhouse at 25°C and 80% relative humidity. After 2 weeks, the inoculated stems developed lesions similar to those observed in the field, whereas controls were asymptomatic. N. musae was re-isolated from the infected stem and identified by both morphological characteristics and DNA sequence analysis. The experiments repeated three times showed similar results. As far as we know, this is the first report of N. musae causing T. chinensis stem blight in the world. The identification of N. musae could provide a certain theoretical basis for field management and further research of T. chinensis.

Soil cadmium stress affects the phyllosphere microbiome and associated pathogen resistance differently in male and female poplars.

Microorganisms associated with the phyllosphere play a crucial role in protecting plants from diseases, and their composition and diversity are strongly influenced by heavy metal contaminants. Dioecious plants are known to exhibit sexual dimorphism in metal accumulation and tolerance between male and female individuals. Hence, in this study we used male and female full-siblings of Populus deltoides to investigate whether the two sexes present differences in their phyllosphere microbiome structures and in their associated resistance to the leaf pathogenic fungus Pestalotiopsis microspora after exposure to excess soil cadmium (Cd). We found that Cd-treated male plants grew better and accumulated more leaf Cd than females. Cd stress reduced the lesion areas on leaves of both sexes after pathogen infection, but male plants exhibited better resistance than females. More importantly, Cd exposure differentially altered the structure and function of the phyllosphere microbiomes between the male and female plants, with more abundant ecologically beneficial microbes and decreased pathogenic fungal taxa harbored by male plants. In vitro toxicity tests suggested that the sexual difference in pathogen resistance could be attribute to both direct Cd toxicity and indirect shifts in the phyllosphere microbiome. This study provides new information relevant for understanding the underlying mechanisms of the effects of heavy metals involved in plant-pathogen interactions.

Synergistic Effects of 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide-Based Derivative and Modified Sepiolite on Flame-Retarded Poly (Ethylene Oxide)-Poly (Butylene Adipate-Co-Terephthalate) Composites.

A 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-based derivative (PN-DOPO) combined with aluminium phosphates-coated sepiolite (Sep@AlPO4) was used to improve the flame retardance, thermal stability and mechanical performances of poly (ethylene oxide) (PEO)/poly (butylene adipate-co-terephthalate) (PBAT) blends. The synergistic effects of PN-DOPO and Sep@AlPO4 on flame-retarded PEO/PBAT composites were systematically discussed. Results indicated that introducing 5 wt% Sep@AlPO4 with 10 wt% PN-DOPO into PEO/PBAT achieved a V-1 rating for the UL-94 test and increased the limiting oxygen index value to 23.7%. Moreover, the peak heat release rate (p-HRR), average HRR and total heat release values of PEO/PBAT/PN10%/Sep5% composites decreased by 35.6%, 11.0% and 23.0% compared with those of PEO/PBAT, respectively. Thermogravimetric analysis (TGA) results confirmed that PN-DOPO/Sep@AlPO4 enhanced the initial thermal stability and char yield of PEO/PBAT matrix, and TGA/Fourier transform infrared spectrometry results revealed that the composites exhibited the characteristic absorption peaks of phosphorous-containing groups and an increase in gas-phase volatiles during thermal degradation. The morphological structures of the residues indicated that PN-DOPO and Sep@AlPO4 mixtures produced a more dense and continuous char layer on the composite surface during burning. Rheological behaviour revealed that higher complex viscosity and modulus values of PEO/PBAT/PN-DOPO/Sep@AlPO4 sample could also promote the crosslinking network structure of condensed phases during combustion. Furthermore, the PEO/PBAT/PN-DOPO/Sep@AlPO4 composites exhibited superior elongation at break and flexural performance than the PEO/PBAT system. All results demonstrated that the PEO/PBAT system modified with PN-DOPO/Sep@AlPO4 showed remarkable flame retardance, and improved thermal stability and mechanical properties, indicating its potential application in areas requiring fire safety.

Cloning and Characterization of Two Novel PR4 Genes from Picea asperata.

Pathogenesis-related (PR) proteins are important in plant pathogenic resistance and comprise 17 families, including the PR4 family, with antifungal and anti-pathogenic functions. PR4 proteins contain a C-terminal Barwin domain and are divided into Classes I and II based on the presence of an N-terminal chitin-binding domain (CBD). This study is the first to isolate two PR4 genes, PaPR4-a and PaPR4-b, from Picea asperata, encoding PaPR4-a and PaPR4-b, respectively. Sequence analyses suggested that they were Class II proteins, owing to the presence of an N-terminal signal peptide and a C-terminal Barwin domain, but no CBD. Tertiary structure analyses using the Barwin-like protein of papaya as a template revealed structural similarity, and therefore, functional similarity between the proteins. Predictive results revealed an N-terminal transmembrane domain, and subcellular localization studies confirmed its location on cell membrane and nuclei. Real-time quantitative PCR (RT-qPCR) demonstrated that PaPR4-a and PaPR4-b expression levels were upregulated following infection with Lophodermium piceae. Additionally, PaPR4-a and PaPR4-b were induced in Escherichia coli, where the recombinant proteins existed in inclusion bodies. The renatured purified proteins showed antifungal activity. Furthermore, transgenic tobacco overexpressing PaPR4-a and PaPR4-b exhibited improved resistance to fungal infection. The study can provide a basis for further molecular mechanistic insights into PR4-induced defense responses.

Diabetes mellitus aggravates humoral immune response in myasthenia gravis by promoting differentiation and activation of circulating Tfh cells.

Myasthenia gravis (MG) is a T-cell-dependent, antibody-mediated autoimmune disease. Diabetes mellitus (DM) is a chronic metabolic disease characterized by hyperglycemia and emerging evidence indicates its profound impacts on the immune homeostasis. Previous studies and our data showed DM might serve as an independent risk factor of MG, yet the underlying immune and molecular mechanisms remain to be addressed. Our study observed that circulating Tfh (cTfh) cells were increased in MG patients with DM and expressed a high level of ICOS. Besides, positive correlations between activated cTfh cells and plasmablasts were documented. Further studies demonstrated hyperglycemia promoted the differentiation and activation of Tfh cells which, in turn, caused abnormal plasmablasts differentiation and antibody secretion through the mTOR signaling pathway. These results indicated DM might aggravate the aberrant humoral immunity in MG patients by augmenting Tfh cells differentiation and function and tight glycemic control might be beneficial for MG patients with DM.

MG53 Inhibits Necroptosis Through Ubiquitination-Dependent RIPK1 Degradation for Cardiac Protection Following Ischemia/Reperfusion Injury.

Rationale: While reactive oxygen species (ROS) has been recognized as one of the main causes of cardiac injury following myocardial infarction, the clinical application of antioxidants has shown limited effects on protecting hearts against ischemia-reperfusion (I/R) injury. Thus, the precise role of ROS following cardiac injury remains to be fully elucidated. Objective: We investigated the role of mitsugumin 53 (MG53) in regulating necroptosis following I/R injury to the hearts and the involvement of ROS in MG53-mediated cardioprotection. Methods and Results: Antioxidants were used to test the role of ROS in MG53-mediated cardioprotection in the mouse model of I/R injury and induced human pluripotent stem cells (hiPSCs)-derived cardiomyocytes subjected to hypoxia or re-oxygenation (H/R) injury. Western blotting and co-immunoprecipitation were used to identify potential cell death pathways that MG53 was involved in. CRISPR/Cas 9-mediated genome editing and mutagenesis assays were performed to further identify specific interaction amino acids between MG53 and its ubiquitin E3 ligase substrate. We found that MG53 could protect myocardial injury via inhibiting the necroptosis pathway. Upon injury, the generation of ROS in the infarct zone of the hearts promoted interaction between MG53 and receptor-interacting protein kinase 1 (RIPK1). As an E3 ubiquitin ligase, MG53 added multiple ubiquitin chains to RIPK1 at the sites of K316, K604, and K627 for proteasome-mediated RIPK1 degradation and inhibited necroptosis. The application of N-acetyl cysteine (NAC) disrupted the interaction between MG53 and RIPK1 and abolished MG53-mediated cardioprotective effects. Conclusions: Taken together, this study provided a molecular mechanism of a potential beneficial role of ROS following acute myocardial infarction. Thus, fine-tuning ROS levels might be critical for cardioprotection.

The Tyrosine Phosphatase PRL Regulates Attachment of Toxoplasma gondii to Host Cells and Is Essential for Virulence.

The pathogenesis of Toxoplasma gondii is mainly due to tissue damage caused by the repeating lytic cycles of the parasite. Many proteins localized to the pellicle of the parasite, particularly kinases, have been identified as critical regulators of the Toxoplasma lytic cycle. However, little is known about the associated protein phosphatases. Phosphatase of regenerating liver (PRL), a highly conserved tyrosine phosphatase, is an oncoprotein that plays pivotal roles in mammalian cells and typically associates with membranes via a conserved prenylation site. PRL in Toxoplasma has a predicted prenylation motif in the C terminus, like other homologs. We have determined that T. gondii PRL (TgPRL) localizes to the plasma membrane and that disruption of TgPRL results in a defect in the parasite's ability to attach to host cells. This function is dependent on both TgPRL's membrane localization and phosphatase activity. Importantly, in vivo experiments have shown that while mice infected with parental strain parasites die within days of infection, those infected with parasites lacking TgPRL not only survive but also develop immunity that confers protection against subsequent infection with wild-type parasites. Immunoprecipitation experiments revealed that the PRL-CNNM (cyclin M) complex, which regulates intracellular Mg2+ homeostasis in mammalian cells, is also present in Toxoplasma. Consistent with this interaction, parasites lacking TgPRL had higher intracellular Mg2+ levels than the parental or complemented strains, suggesting TgPRL is involved in regulating intracellular Mg2+ homeostasis. Thus, TgPRL is a vital regulator of the Toxoplasma lytic cycle and virulence, showing its potential as a target of therapeutic intervention. IMPORTANCE Infection with Toxoplasma gondii can lead to severe and even life-threatening diseases in people with compromised or suppressed immune systems. Unfortunately, drugs to combat the parasite are limited, highly toxic, and ineffective against the chronic stage of the parasite. Consequently, there is a strong demand for the discovery of new treatments. A comprehensive understanding of how the parasite propagates in the host cells and which proteins contribute to the parasite's virulence will facilitate the discovery of new drug targets. Our study meets this objective and adds new insights to understanding the lytic cycle regulation and virulence of Toxoplasma by determining that the protein phosphatase TgPRL plays a vital role in the parasite's ability to attach to host cells and that it is essential for parasite virulence.

UCHL1 protects against ischemic heart injury via activating HIF-1α signal pathway.

Ubiquitin carboxyl-terminal esterase L1 (UCHL1) has been thought to be a neuron specific protein and shown to play critical roles in Parkinson's Disease and stroke via de-ubiquiting and stabilizing key pathological proteins, such as α-synuclein. In the present study, we found that UCHL1 was significantly increased in both mouse and human cardiomyocytes following myocardial infarction (MI). When LDN-57444, a pharmacological inhibitor of UCHL1, was used to treat mice subjected to MI surgery, we found that administration of LDN-57444 compromised cardiac function when compared with vehicle treated hearts, suggesting a potential protective role of UCHL1 in response to MI. When UCHL1 was knockout by CRISPR/Cas 9 gene editing technique in human induced pluripotent stem cells (hiPSCs), we found that cardiomyocytes derived from UCHL1-/- hiPSCs were more susceptible to hypoxia/re-oxygenation induced injury as compared to wild type cardiomyocytes. To study the potential targets of UCHL1, a BioID based proximity labeling approach followed by mass spectrum analysis was performed. The result suggested that UCHL1 could bind to and stabilize HIF-1α following MI. Indeed, expression of HIF-1α was lower in UCHL1-/- cells as determined by Western blotting and HIF-1α target genes were also suppressed in UCHL1-/- cells as quantified by real time RT-PCR. Recombinant UCHL1 (rUCHL1) protein was purified by E. Coli fermentation and intraperitoneally (I.P.) delivered to mice. We found that administration of rUCHL1 could significantly preserve cardiac function following MI as compared to control group. Finally, adeno associated virus mediated cardiac specific UCHL1 delivery (AAV9-cTNT-m-UCHL1) was performed in neonatal mice. UCHL1 overexpressing hearts were more resistant to MI injury as compare to the hearts infected with control virus. In summary, our data revealed a novel protective role of UCHL1 on MI via stabilizing HIF-1α and promoting HIF-1α signaling.

Soil cadmium stress reduced host plant odor selection and oviposition preference of leaf herbivores through the changes in leaf volatile emissions.

The Elemental defense hypothesis suggested that metal accumulation in plant tissues could serve as direct defense to reduce herbivore feeding preference as metals are toxic to phytophagous insects. However, the indirectly defensive role of heavy metals on host plant odor selection and oviposition preference of leaf herbivores through the changes in leaf volatile organic compounds (VOCs) is still unknown. In this study, we used a local woody plant species, Populus yunnanensis, to investigate whether soil cadmium (Cd) stress could affect plant VOC production and whether Cd-mediated changes in leaf VOC emissions will further influence the host plant odor and oviposition preferences of female adults of a specialist and a generalist herbivore species. The results clearly showed that the soil Cd stress could prominently induce leaf total VOC emissions of P. yunnanensis and such induction was positively correlated with leaf Cd accumulation. Herbivore olfactometer bioassays further demonstrated that the VOCs released by P. yunnanensis under Cd exposure are far less attractive to both of the specialist and generalist female adults compared to control plants, leading to significant reduction in oviposition on Cd-treated plants. Moreover, the host plant odor selection and oviposition preference of the two herbivore species were all negatively correlated with leaf total VOC emissions, which confirmed the defensive role of Cd-induced VOCs for deterring the female insects. The result will extend the existing knowledge of the Elemental defense hypothesis and provide new insight into predicting the herbivore damage level of poplar species that naturally occurred in metal-polluted habitats.

Combination of Antioxidant Enzyme Overexpression and N-Acetylcysteine Treatment Enhances the Survival of Bone Marrow Mesenchymal Stromal Cells in Ischemic Limb in Mice With Type 2 Diabetes.

Background Therapy with mesenchymal stem cells remains a promising but challenging approach to critical limb ischemia in diabetes because of the dismal cell survival. Methods and Results Critical limb ischemia in type 2 diabetes mouse model was used to explore the impact of diabetic limb ischemia on the survival of bone marrow mesenchymal stromal cells (bMSCs). Inhibition of intracellular reactive oxygen species was achieved with concomitant overexpression of superoxide dismutase (SOD)-1 and glutathione peroxidase-1 in the transplanted bMSCs, and extracellular reactive oxygen species was attenuated using SOD-3 overexpression and N-acetylcysteine treatment. In vivo optical fluorescence imaging and laser Doppler perfusion imaging were used to track cell retention and determine blood flow in diabetic ischemic limb, respectively. Survival of the transplanted bMSCs was significantly decreased in diabetic ischemic limb compared with the control. In vitro study indicated that advanced glycation end products, not high glucose, significantly decreased the proliferation of bMSCs and increased their apoptosis associated with increased reactive oxygen species production and selective reduction of SOD-1 and SOD-3. In vivo study demonstrated that concomitant overexpression of SOD-1, SOD-3, and glutathione peroxidase-1, or host treatment with N-acetylcysteine, significantly enhanced in vivo survival of transplanted bMSCs, and improved critical limb ischemia in diabetic mice. Combination of triple antioxidant enzyme overexpression in bMSCs with host N-acetylcysteine treatment further improved bMSC survival with enhanced circulatory and functional recovery from diabetic critical limb ischemia. Conclusions Simultaneous suppression of reactive oxygen species from transplanted bMSCs and host tissue could additively enhance bMSC survival in diabetic ischemic limb with increased therapeutic efficacy in diabetes.

Natural killer cells promote the differentiation of follicular helper T cells instead of inducing apoptosis in myasthenia gravis.

Recent evidence has shown that natural killer (NK) cells have an immunoregulatory function in the pathogenesis of myasthenia gravis (MG). In this study, the phenotype and function of NK cell subsets in peripheral blood of new-onset MG (N-MG) and stable MG (S-MG) patients were explored. Circulating CD56dim and CD56bright NK cells were increased and decreased, respectively, in patients with N-MG and S-MG compared with healthy control (HC). Moreover, all circulating NK cell subsets from N-MG patients showed significantly lower expression of activating receptor NKG2D and production of Interferon (IFN) -γ than that from HC. The killing effects of NK cells on CD4+ T cells and Tfh cells were impaired in MG patients, whereas, they promoted the differentiation and activation of Tfh cells. These data indicated that the immune-regulation of NK cells on CD4+ T cells and Tfh cells in MG patients was abnormal, which may contribute to the immune-pathological mechanism of MG.

Prophylactic administration of fingolimod (FTY720) ameliorated experimental autoimmune myasthenia gravis by reducing the number of dendritic cells, follicular T helper cells and antibody-secreting cells.

Fingolimod (FTY720), a sphingosine 1-phosphate (S1P) receptor antagonist, possesses potent immunomodulatory activity via lymphocyte homing. The effects of FTY720 have been widely studied in various T-cell-mediated autoimmune diseases, while the immunomodulatory effects on experimental autoimmune myasthenia gravis (EAMG), a typical disease model for antibody-mediated autoimmunity, remain elusive. In the present study, FTY720 was administered to EAMG rats as prophylaxis. The clinical scores were recorded every other day, and serum antibodies at different time points were measured by enzyme-linked immunosorbent assay (ELISA). The immune cell subsets in the spleen, bone marrow, circulation, and thymus were determined by flow cytometry. The prophylactic administration alleviated EAMG symptoms by reducing the level of serum antibodies IgG and its isotype IgG2b on days 30 and 46 post immunization, as well as IgG and Ig kappa antibody-secreting cells in the spleen and bone marrow. The mitigated humoral immune response can be attributed to the decreased dendritic cells, follicular T help cells (Tfh) and Tfh subsets (Tfh1, Tfh2, and Tfh17), and T helper cell subsets (Th1, Th2, and Th17) in the spleen. The promotion of lymphocyte homing and inhibition of thymocyte egress contribute to the effects of FTY720 on these effector T cell subsets. Overall, the prophylactic administration of FTY720 ameliorated EAMG partially by regulating humoral immune response，suggesting that FTY720 could be part of a pharmacological strategy for managing myasthenia gravis.

Gadd45b is a novel mediator of depression-like behaviors and neuroinflammation after cerebral ischemia.

BACKGROUND: Poststroke depression (PSD) is an important consequence after stroke, with a negative impact on stroke outcome. Recent evidence points to a modulatory role of Growth arrest and DNA-damage-inducible protein 45 beta (Gadd45b) in depression. Herein, we evaluated the antidepressant efficacy and mechanism underlying the potent therapeutic effects of Gadd45b after cerebral ischemia. METHODS: Adult male Sprague-Dawley rats were subjected to cerebral ischemia by permanent middle cerebral artery occlusion (MCAO). The sucrose preference test (SPT), forced swim test (FST), and tail suspension test (TST) were performed after completing MCAO to study the antidepressant-like effects. The expression of brain-derived neurotrophic factor (BDNF) and neuroinflammation were determined in the hippocampus. RESULTS: We showed that Gadd45b knockdown induced depression-like behaviors after cerebral ischemia, including increased immobility time in the FST and TST and reduced sucrose preference. Gadd45b knockdown enhanced the expression of pro-inflammatory cytokines IL-6 and TNF-α, accompanying with decreased protein levels of BDNF in the hippocampus. Moreover, the levels of phosphorylated ERK and CREB, which have been implicated in events downstream of BDNF signaling, were also decreased after cerebral ischemia. CONCLUSION: Hence, the results showed that Gadd45b is a promising drug candidate for treating PSD and possibly other nervous system diseases associated with neuroinflammation. Gadd45b may have therapeutic potential for PSD through BDNF-ERK-CREB pathway and neuroinflammation.

Stem Rot Disease of Juglans sigillata Dode Caused by Fusarium fujikuroi in China.

Juglans sigillata Dode is an endemic species in the southwest China, and is an important nut and woody oil tree. The shell of its fruit is hard and can be used to make various crafts. From 216 to 2019, typical stem rot symptoms of 8-year-old J. sigillata were observed in cultivated fields in a 600-ha orchard in Zigong, Sichuan province, China. At this orchard, approximately 35% of the trees have been seriously damaged over the past few years. The typical symptoms were water-soaking on the stem, rotting, wilting, and blighting, eventually leading to the death of the plant. In June, ten diseased tissues were collected and surface-sterilized by 3% NaClO and 75% alcohol. Morphological observations were made from the isolates grown on Potato dextrose agar (PDA) and incubated at 25°C for 3 to 9 days. Morphological characteristics were made on pure cultures grown on Synthetic low nutrient agar (SNA). Five isolates with similar morphology were isolated from single spores. Colonies on PDA reached 8.3 cm in diameter after 6 days at 25 °C, aerial mycelia were white to cream and wol-like, later turning violet and dark purple with age. The hyphae of the strain were colorless and septate. There were two types of conidia on SNA, microconidia and macroconidia. Microconidia (n = 50) were oval, elliptic or clavate, no septate, 2.2 to 3.8 × 7.6 to11.7 µm. Conidiophores were branched or unbranched, solitary or in groups, phialides cylindrical to flask-shaped, monophialidic and polyphialidic. Macroconidia (n = 50) were long slender with a curved apical cell and foot-like basal cell, 3 to 4 septate and 2.1 to 3.9 × 26.2 to 53.4 µm. For molecular identification, the internal transcribed spacer (ITS), ß-tubulin (TUB2), translation elongation factor (TEF1) and large subunit (LSU) were amplified with the corresponding primer pairs ITS1/ITS4 (White et al. 1990), BT2A/BT2B, EF1/EF2 (O'Donnell et al. 1997), and LROR/LR5 (Rehner and Samuels 1994), respectively. BLAST search results indicated that the ITS, TUB2, TEF1, LSU sequences (GenBank acc. nos. MT791384, MT786729, MN853324, and MT705246) showed 99 to100% identity with Fusarium fujikuroi sequences at NCBI (GenBank acc. nos. MG798789, MH398245, MK604519 and KJ954504). The results were confirmed by multilocus phylogenetic analysis. Based on the morphological characteristics and molecular analysis of the isolates, the fungus was identified as F. fujikuroi (Leslie and Summerell 2006). Koch's postulates were checked under controlled conditions. Fifteen 2-year-old healthy potted J. sigillata were inoculated by pricking the epidermis of stem with a needle and applying 150 µl of a microconidial suspension (1 × 106 spores/ml) to the wounded surface with a brush. Sterilizd distilled water was used as the control. The experiment was repeated three times. All the plants were incubated at 25 ± 2°C after inoculation for daily observation of disease development. After 12 days, the inoculated plants showed the same symptoms as observed in the original diseased plants, while the control plants were asymptomatic. The fungus was re-isolated from the symptomatic stems and was completely identical to the isolates used to inoculate the plants. Thus, we confirmed that F. fujikuroi caused the stem rot of J. sigillata. To our knowledge, this is the first report of this fungus causing stem rot in J. sigillata in China. Our results can help identify stem rot disease of J. sigillata and develop control measures for the disease.

M1 Macrophage Derived Exosomes Aggravate Experimental Autoimmune Neuritis via Modulating Th1 Response.

Guillain-Barré syndrome (GBS), an immune-mediated disorder affecting the peripheral nervous system, is the most common and severe acute paralytic neuropathy. GBS remains to be potentially life-threatening and disabling despite the increasing availability of current standard therapeutic regimens. Therefore, more targeted therapeutics are in urgent need. Macrophages have been implicated in both initiation and resolution of experimental autoimmune neuritis (EAN), the animal model of GBS, but the exact mechanisms remain to be elucidated. It has been increasingly appreciated that exosomes, a type of extracellular vesicles (EVs), are of importance for functions of macrophages. Nevertheless, the roles of macrophage derived exosomes in EAN/GBS remain unclear. Here we determined the effects of macrophage derived exosomes on the development of EAN in Lewis rats. M1 macrophage derived exosomes (M1 exosomes) were found to aggravate EAN via boosting Th1 and Th17 response, while M2 macrophage derived exosomes (M2 exosomes) showed potentials to mitigate disease severity via a mechanism bypassing Th1 and Th17 response. Besides, both M1 and M2 exosomes increased germinal center reactions in EAN. Further in vitro studies confirmed that M1 exosomes could directly promote IFN-γ production in T cells and M2 exosomes were not capable of inhibiting IFN-γ expression. Thus, our data identify a previously undescribed means that M1 macrophages amplify Th1 response via exosomes and provide novel insights into the crosstalk between macrophages and T cells as well.

Synthesis of Fe3O4@Gd2O3:Tb3+@SiOx multifunctional nanoparticles and their luminescent, magnetic and hyperthermia properties.

Multifunctional Fe3O4@Gd2O3:Tb3+@SiOx nanoparticles were successfully synthesized by co-precipitation and polyol methods. The synthesized nanoparticles were composed by cubic phase as core of Fe3O4 and Gd2O3:Tb3+ and the shell of amorphous SiOx. The composites exhibited a spherical shape with a diameter of 10-15 nm and highly uniform dispersion. They showed not only excellent fluorescence under excitation at a wavelength of 278 nm, but also strong magnetic responsiveness (MS = 24.040 emu g-1). The results of magnetic resonance imaging in vitro (r1 = 6.00 mm-1 s-1, r2 = 63.95 mm-1 s-1) showed that the samples could be used as T1-positive and T2-negative contrast agents. In addition, it was found that Fe3O4@Gd2O3:Tb3+@SiOx attains hyperthermia temperature (43 °C) in 90 s under the alternating current magnetic field, and their specific absorption rate (229.9 w g-1) was higher than that of Fe3O4 (183.92 w g-1). Hence, the multifunctional nanoparticle could be used for the diagnosis and therapy of cancer.

N-acetylcysteine prevents oxidized low-density lipoprotein-induced reduction of MG53 and enhances MG53 protective effect on bone marrow stem cells.

MG53 is an important membrane repair protein and partially protects bone marrow multipotent adult progenitor cells (MAPCs) against oxidized low-density lipoprotein (ox-LDL). The present study was to test the hypothesis that the limited protective effect of MG53 on MAPCs was due to ox-LDL-induced reduction of MG53. MAPCs were cultured with and without ox-LDL (0-20 µg/mL) for up to 48 hours with or without MG53 and antioxidant N-acetylcysteine (NAC). Serum MG53 level was measured in ox-LDL-treated mice with or without NAC treatment. Ox-LDL induced significant membrane damage and substantially impaired MAPC survival with selective inhibition of Akt phosphorylation. NAC treatment effectively prevented ox-LDL-induced reduction of Akt phosphorylation without protecting MAPCs against ox-LDL. While having no effect on Akt phosphorylation, MG53 significantly decreased ox-LDL-induced membrane damage and partially improved the survival, proliferation and apoptosis of MAPCs in vitro. Ox-LDL significantly decreased MG53 level in vitro and serum MG53 level in vivo without changing MG53 clearance. NAC treatment prevented ox-LDL-induced MG53 reduction both in vitro and in vivo. Combined NAC and MG53 treatment significantly improved MAPC survival against ox-LDL. These data suggested that NAC enhanced the protective effect of MG53 on MAPCs against ox-LDL through preventing ox-LDL-induced reduction of MG53.