Abstract 17: Ultra-early Activation Of Neuroinflammatory Cascade Following Acute Stroke: Plasma And Extracellular Vesicle Biomarkers From A Mobile Stroke Unit

Background: Neuroinflammation is ubiquitous in acute stroke and worsens outcome. However, the precise timing of the inflammatory response is unknown, hindering the design of acute anti-inflammatory therapeutic interventions. We used a mobile stroke unit (MSU) to identify the onset of the neuroinflammatory cascade within minutes of symptom onset.

Methods: The study is a prospective, cohort investigation of ultra-early blood- and extracellular vesicle (EV)-derived markers of neuroinflammation and outcome in acute stroke. Blood was obtained on the MSU with head CT, and from healthy controls. Plasma biomarkers were analyzed with ELISA, SIMOA and ECL. EVs were isolated with HSP pull down. Confirmed strokes, mimics and healthy controls were compared. Variables included demographics, mRS, NIHSS and discharge disposition.

Results: Forty one adults were analyzed, including 15 patients treated on the MSU between August 2021 and April 2022, and 26 controls. For MSU patients, median age was 74 (range 36-97) years, 60% were female, and 80% white. Ten (67%) were diagnosed as stroke, with 8 (53%) confirmed and 2 likely TIA or stroke averted by thrombolysis; 5 were stroke mimics. For strokes, median initial NIHSS score was 11 (range 4-19) and 6 (75%) received tPA. Blood was obtained a median of 58 (range 36-133) minutes after symptom onset. Within 36 minutes after stroke, plasma interleukin-6 (IL-6), neurofilament light chain (NfL), ubiquitin C-terminal hydrolase L1 (UCH-L1) and glial fibrillary acidic protein (GFAP) were elevated by as much as 10 times normal. In EVs, matrix metalloproteinase-9 (MMP-9), chemokine (C-X-C motif) ligand 4 (CXCL4), C-reactive protein (CRP), IL-6, osteopontin (OPN) and platelet and endothelial cell adhesion molecule 1 (PECAM1) were elevated. Inflammatory markers increased rapidly in the first two hours, and continued rising for 24 hours.

Conclusions: This study found the inflammatory cascade is activated as early as 36 minutes after stroke, and progresses rapidly. This is earlier than observed previously in humans, and suggests injury from neuroinflammation may occur faster than had been surmised. The findings may inform development of immunomodulatory therapies for acute stroke, and lead to new diagnostic tools and improved outcomes.

[Value of glycosylated hemoglobin A1c and apolipoprotein A-1 ratio on predicting outcome of patients with acute coronary syndrome]

Objective: To investigate the predictive value of glycosylated hemoglobin A1c/apolipoprotein A-1 (HbA1c/ApoA-1) ratio for major adverse cardiovascular events (MACEs) in patients with acute coronary syndrome (ACS). Methods: The present study is a retrospective cohort study. ACS patients who were hospitalized and underwent coronary angiography at Beijing Hospital from March 2017 to March 2019 were enrolled. Baseline information such as sex, age, previous history, Gensini score, HbA1c and ApoA-1 were analyzed. Patients were divided into two groups according to presence or absence of MACEs and the difference on HbA1c/ApoA-1 ratio was compared between the two groups. According to the tertiles of HbA1c/ApoA-1 levels, patients were divided into high (5.87-16.12), medium (4.50-5.83) and low (2.11-4.48) HbA1c/ApoA-1 groups. Cox proportional risk model was used to evaluate the differences in MACEs and all-cause mortality among the three groups. Kaplan-Meier survival analysis was used to compare the differences of MACEs between the various HbA1c/ApoA-1 groups. Results: A total of 366 ACS patients were included in this study. The mean age of the patients was (65.9±10.3) years. There were 59 MACEs and 10 all-cause deaths during the mean of (22.3±4.4) months follow-up. After adjusting for age, systolic blood pressure, history of diabetes and Gensini score, the incidence of MACEs was 2.45 times higher in the high HbA1c/ApoA-1 group than in the low HbA1c/ApoA-1 group (95%CI 1.16-5.18, P=0.019). There was no significant difference in all-cause mortality between the high and low HbA1c/ApoA-1 groups (P=1.000). Kaplan-Meier survival analysis showed that patients in the high HbA1c/ApoA-1 group had the highest risk of MACEs, while patients in the low HbA1c/ApoA-1 group had the lowest risk of MACEs (P<0.01). Spearman rank correlation analysis showed that HbA1/ApoA-1 ratio was positively correlated with Gensini score in ACS patients (r=0.274, P<0.01). Conclusion: High HbA1c/ApoA-1 ratio was an independent risk factor for MACEs in ACS patients. Patients with high HbA1c/ApoA-1 ratio had more severe coronary artery disease lesions. HbA1c/ApoA-1 ratio may be used as a potential risk stratification biomarker for ACS patients, it might be useful for the early identification of high-risk population and for predicting the incidence of MACEs among ACS patients.

The effect of hippocampal NR2B-containing NMDA receptors on chronic cognitive dysfunction in rats with temporal lobe epilepsy

Background

We have previously reported that hippocampal long-term potentiation (LTP) was suppressed in temporal lobe epilepsy (TLE) rats. The N-methyl-D-aspartic acid receptors containing 2B subunit (NR2B-NMDARs) are indispensable to induce the LTP of hippocampus. However, it is still unknown whether the NR2B-NMDARs are implied with the cognitive dysfunction in TLE rats.

Methods

The TLE model was lithium chloride-pilocarpine (li-pilo) model. Morris water maze test was used to evaluate the cognitive function of epileptic rats. Expression of hippocampal NR2B-NMDAs was evaluated by western blotting. Stereotactic injection of NMDA, an agonist of NR2B-NMDARs, into the hippocampus of TLE rats was used to investigate the role of NR2B-NMDARs on cognitive dysfunction.

Results

Cognitive function TLE rats was significantly reduced compared with controls in the Morris water maze test (P < 0.05). Western blotting data showed the down-expression of hippocampal NR2B-NMDARs and p-NR2B in TLE rats compared with the control (P < 0.05). In addition, hippocampal stereolocalization of NMDA injection improved partially the learning and memory in TLE rats (P < 0.05).

Conclusions

Down-expression and low activity of hippocampal NR2B-NMDARs may be implied with chronic cognitive dysfunction in TLE rats.

Optimized study of an in vitro 3D culture of preantral follicles in mice

BACKGROUND

In vitro culture of preantral follicles is a promising technology for fertility preservation.

OBJECTIVES

This study aims to investigate an optimized three-dimensional (3D) fetal bovine serum (FBS)-free preantral follicle culture system having a simple and easy operation.

METHODS

The isolated follicles from mouse ovaries were randomly divided in an ultra-low attachment 96-well plates supplement with FBS or bovine serum albumin (BSA) culture or encapsulated with an alginate supplement with FBS or BSA culture. Meanwhile, estradiol (E₂) concentration was assessed through enzyme-linked immunosorbent assay of culture supernatants. The diameter of follicular growth was measured, and the lumen of the follicle was photographed. Spindle microtubules of oocytes were detected via immunofluorescence. The ability of oocytes to fertilize was assessed using in vitro fertilization.

RESULTS

The diameters were larger for the growing secondary follicles cultured in ultra-low attachment 96-well plates than in the alginate gel on days 6, 8, and 10 (p < 0.05). Meanwhile, the E₂ concentration in the BSA-supplemented medium was significantly higher in the alginate gel than in the other three groups on days 6 and 8 (p < 0.05), and the oocytes in the FBS-free system could complete meiosis and fertilization in vitro.

CONCLUSIONS

The present study furnishes insights into the mature oocytes obtained from the 3D culture of the preantral follicle by using ultra-low attachment 96-well plate with an FBS-free system in vitro and supports the clinical practices to achieve competent, mature oocytes for in vitro fertilization.

Biochar alleviating heavy metals phytotoxicity in sludge-amended soil varies with plant adaptability

Recycling sewage sludge (SS) to soil potentially causes soil heavy metal (HM) pollution and plant phytotoxicity. Biochar plays an important role in alleviating HM phytotoxicity, and responses vary with the feedstocks and usage of biochar. However, the effect of plant adaptability on biochar-mediated alleviation is poorly understood. Here, SS-derived biochar (SB) and rice straw-derived biochar (RB) applied at rates of 1.5% and 3% (W/W, SB1.5, SB3, RB1.5, and RB3) were used to improve the properties of soil amended with SS at 50% (W/W). Alleviation of phytotoxicity by biochar was further analyzed with SS-sensitive plant Monstera deliciosa and SS-resistant plant Ruellia simplex. Results revealed that both SB and RB significantly decreased the soil's bulk density and increased water retention. They also changed soil organic matter content and HMs fractionation. The addition of SB or RB alleviated the SS phytotoxicity, and they significantly promoted the growth and the root morphology and physiological index of M. deliciosa. But for R. simplex, these significant changes only synchronously occurred in SB3 treatment. The alleviation in M. deliciosa was more prominent and more closely connected with soil property changes than in R. simplex. Also, more soil property predictors were observed to play an important role in M. deliciosa growth than in R. simplex growth. These results indicated that biochar alleviating HMs phytotoxicity in SS-amended soil is associated with the changes of soil property. Moreover, the alleviation varies more prominently with plant adaptability than with biochar feedstocks and usage.

Higher Levels of IgG3 Antibodies in Serum, But Not in CSF, Distinguish Multiple Sclerosis From Other Neurological Disorders

Increased intrathecal IgG and oligoclonal bands (OCB) are seminal features of multiple sclerosis (MS). Although no such differences in MS blood total IgG antibodies have been reported, serum OCB are a common and persistent finding in MS and have a systemic source. Recent studies showed that IgG3⁺ B cells and higher levels of serum IgG3 are linked to the development of MS. Additionally, intrathecal IgG synthesis in MS is associated with IgG3 heavy chain gene single nucleotide polymorphisms, and there is a strong relationship between susceptibility to MS and an IgG3 restriction fragment length polymorphism. These studies support the role of IgG3 in disease pathogenesis. Using multiple immunoassays, we investigated levels of total IgG, IgG1, and IgG3 in sera and CSF of 102 MS patients (19 paired CSF and sera), 76 patients with other neurological disorders (9 paired CSF and sera), and 13 healthy controls. We show that higher levels of total IgG and IgG3 antibodies were detected in MS serum, but not in CSF, which distinguishes MS from other inflammatory and non-inflammatory neurological disorders, with Receiver Operating Characteristic (ROC) Curves 0.79 for both IgG3 & total IgG. Our data support the notion that IgG3 antibodies may be a potential candidate for MS blood biomarker development.

The Complete Mitochondrial Genome of Eurasian Minnow (Phoxinus cf. phoxinus) from the Heilongjiang River, and Its Phylogenetic Implications

Simple Summary

Fishes of genus Phoxinus belong to the family Leusciscidae and are widely distributed in Eurasia. Since the early 20th century, it has generally been accepted that the European minnow (P. phoxinus) was the only valid species of Phoxinus in Europe. After the loss of most species from North America and Asia, only those taxa in Euasia originally placed under the name P. phoxinus remain in the genus. In recent years, more than 20 lineages of genus Phoxinus have been identified in Europe, more than 10 of which have been considered as valid species in taxonomy. Existing morphological and genetic cues suggest distinct differences between Asian and European members of Phoxinus. Mitochondrial DNA from European Phoxinus spp. and their Asian relatives provide evidence that Far Eastern phoxinins should be divided into two genera: Phoxinus and Rhynchocypris. The updated phylogeny of Phoxinus indicates five mtDNA lineages in Asia. The validity of some of these lineages have been supported previously by morphological evidence.

Abstract

Over the past two decades, the genus Phoxinus has undergone extensive taxonomic revision and many new species or mitochondrial lineages have been found in Europe. However, Asian populations of Phoxinus spp. have received less attention and have rarely been compared with their European relatives. In this study, we deciphered the 16,789-nucleotide mitochondrial genome of Phoxinus cf. phoxinus from the Heilongjiang River (HLJ) and compared it with other known mitogenomes or partial mitochondrial DNA (mtDNA) sequences of Phoxinus spp. We discovered that all known mitochondrial genomes of Phoxinus had a typical mtDNA architecture across vertebrates, but their D-loop regions varied greatly in length. A repetitive motif of ~130 bp was identified in the D-loop regions of Phoxinus spp. The unusual repetitive structure was revealed at the beginning of D-loop regions of all known mitogenomes of Phoxinus spp. The length differences of the D-loop region were attributed mainly to the number of repetitive motifs and the inserted sequences among them. However, this repetitive structure was absent in the other Far East phoxinins. This is further evidence for the notion that Far Eastern phoxinins should be divided into two genera: Phoxinus and Rhynchocypris. All mtDNA sequences (including three mitogenomes) from South Korea represent the same genetic lineage, as there were only slight differences among them. The remaining six mtDNA sequences are highly divergent and represent different lineages of the genus, as supported by partial mtDNA sequences. The updated phylogeny of genus Phoxinus suggests that there are five distinct mtDNA lineages in Asia. The Asian lineages have diverged markedly from their European relatives and should not be included with the European minnow (P. phoxinus).

Phenotype and Neuronal Cytotoxic Function of Glioblastoma Extracellular Vesicles

Glioblastoma (GBM) is the most aggressive and lethal form of brain tumor. Extracellular vesicles (EVs) released by tumor cells play a critical role in cellular communication in the tumor microenvironment promoting tumor progression and invasion. We hypothesized that GBM EVs possess unique characteristics which exert effects on endogenous CNS cells including neurons, producing dose-dependent neuronal cytotoxicity. We purified EVs from the plasma of 20 GBM patients, 20 meningioma patients, and 21 healthy controls, and characterized EV phenotypes by electron microscopy, nanoparticle tracking analysis, protein concentration, and proteomics. We evaluated GBM EV functions by determining their cytotoxicity in primary neurons and the neuroblastoma cell line SH-SY5Y. In addition, we determined levels of IgG antibodies in the plasma in GBM (n = 82), MMA (n = 83), and controls (non-tumor CNS disorders and healthy donors, n = 50) with capture ELISA. We discovered that GBM plasma EVs are smaller in size and had no relationship between size and concentration. Importantly, GBM EVs purified from both plasma and tumor cell lines produced IgG-mediated, complement-dependent apoptosis and necrosis in primary human neurons, mouse brain slices, and neuroblastoma cells. The unique phenotype of GBM EVs may contribute to its neuronal cytotoxicity, providing insight into its role in tumor pathogenesis.

Cistanche deserticola polysaccharides extracted from Cistanche deserticola Y.C. Ma promote the differentiation of mouse female germline stem cells in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese herbal medicine Cistanche deserticola Y.C. Ma has been recorded and treatment for infertility and impotence since ancient times, which is widely distributed in northwest China, and is mainly composed of phenylethanol glycosides, iridoids, lignans, polysaccharides, alkaloids, etc. C. deserticola polysaccharides (CDPs) is one of its main active ingredients, studies of its effect on germline stem cells are limited so far.

AIM OF THE STUDY

The aim of this study was to clarify that CDPs promoted the differentiation of FGSCs in vitro, and to initially clarify its possible cell signaling pathways.

MATERIAL AND METHODS

The cells were randomly divided into two groups. Normal FGSCs culture medium and the optimal concentration of CDPs (0.5 μg/mL) were added for culture, which was the selected treatment concentration that could promote cell differentiation on the basis of maintaining cell viability. After treatment for different time periods (12 h, 24 h, 36 h, 48 h), the cell proliferation and differentiation were evaluated by CCK-8, real-time PCR (qPCR), cell immunofluorescence and Western blot. Subsequently, RNA-Seq and data analysis were used to preliminarily analyze and verify the different genes and possible signal pathways.

RESULTS

Under the treatment of CDPs, cell viability was relatively better, and the expression of meiotic markers stimulated by retinoic acid gene 8 protein (Stra8) and synaptonemal complex protein 3 (Sycp3) significantly increased. In addition, their cell morphology was more similar to oocytes. Comparison of gene expression in FGSCs identified key differential expression genes (DEGs) by RNA-Seq that consisted of 549 upregulated and 465 downregulated genes. The DEGs enriched in the functional categories of germline cell development and relevant signaling pathways, which jointly regulate self-renewal and differentiation of FGSCs. The transforming growth factor β (TGF-β) signaling pathway and bone morphogenetic protein (BMP) signaling pathway might be activated to synergistically influence cell differentiation during the CDPs treatment of FGSCs.

CONCLUSION

These findings indicated that CDPs could promote the differentiation of FGSCs in vitro and could be regulated by different DEGs and signal transduction. Preliminary mechanism studies have shown that CDPs can exert their biological activities by regulating the TGF-β and BMP signaling pathways.

Liposomal docosahexaenoic acid halts atherosclerosis progression

Background

Atherosclerosis is the main cause underlying cardiovascular disease (CVD). Docosahexaenoic acid (DHA, 22:6n-3) is a hydrophobic polyunsaturated fatty acid that exerts anti-inflammatory and antioxidant activities. However, the beneficial effects of DHA on CVD have been controversial likely due to variations in bioavailability after oral intake.

Purpose

In this study, we aim to investigate the potential inhibiting properties of liposomal DHA on atherosclerosis progression upon intravenous administration.

Methods

Four weeks old ApoE−/− and LDLr−/− mice were fed on athero-inducing high fat diet for 4 weeks and then randomly divided into two groups. The mice received either control liposomes (control group) or liposomes containing DHA (liposomal DHA treatment group) via intravenous injection, twice a week for 8 weeks while still being fed on high fat diet. At the experiment endpoint, whole aortas were collected for Oil Red O staining to quantify plaque area or for biochemical analysis. Plasma was collected for total cholesterol measurement and lipidomic analysis. Aortic roots were used for histological analysis.

Results

Upon intravenous injection, as shown by IVIS imaging, DHA-containing liposomes accumulated preferentially in the atherosclerotic plaques. Compared to control liposomes, liposomal DHA treatment reduced the atherosclerotic plaque area in both atherosclerosis animal models, with the total plaque area decreased by 35.8% in ApoE−/− mice, (p&lt;0.001) and by 22.4% in LDLr−/− mice (p&lt;0.05). Plaque composition analysis revealed that liposomal DHA treatment increased collagen content and reduced the number of macrophages and neutral lipid within the plaques, resulting in a lower plaque vulnerability index (1.095 for liposomal DHA treated group vs. 1.692 for control group, p&lt;0.05). Among those plaque macrophages, as demonstrated by immunohistology, M2 (anti-inflammatory) macrophages accounted for 4.44% in liposomal DHA treated mice and 2.24% in control liposomes treated mice (p&lt;0.05). In agreement with the histology results, higher mRNA expression levels of anti-inflammatory markers (IL-10, CD206 and CD163) and collagen type 1 were determined in aortic tissue after liposomal DHA treatment. Moreover, liposomal DHA did not change total cholesterol level in the blood but significantly lowered plasma levels of several species of triglycerides. In vitro experiment with bone marrow derived macrophages showed that liposomal DHA was able to suppress lipopolysaccharide-induced inflammatory response and oxidative stress.

Conclusions

Our findings demonstrate that incorporation of DHA in injectable liposomes is an effective way to increase the inhibitory effects of DHA on halting the progression of atherosclerosis via lowering circulating triglycerides, reducing plaque inflammation, and enhancing plaque stability. Intravenous administration of liposomal DHA may become an efficacious strategy for the treatment of atherosclerosis.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): NUSMed Seed Fund

Niche differentiation among comammox (Nitrospira inopinata) and other metabolically distinct nitrifiers

Due to global change, increasing nutrient input to ecosystems dramatically affects the nitrogen cycle, especially the nitrification process. Nitrifiers including ammonia-oxidizing archaea (AOAs), ammonia-oxidizing bacteria (AOBs), nitrite-oxidizing bacteria (NOBs), and recently discovered complete ammonia oxidizers (comammoxs) perform nitrification individually or in a community. However, much remains to be learned about their niche differentiation, coexistence, and interactions among those metabolically distinct nitrifiers. Here, we used synthetic microbial ecology approaches to construct synthetic nitrifying communities (SNCs) with different combinations of Nitrospira inopinata as comammox, Nitrososphaera gargensis as AOA, Nitrosomonas communis as AOB, and Nitrospira moscoviensis as NOB. Our results showed that niche differentiation and potential interactions among those metabolically distinct nitrifiers were determined by their kinetic characteristics. The dominant species shifted from N. inopinata to N. communis in the N4 community (with all four types of nitrifiers) as ammonium concentrations increased, which could be well explained by the kinetic difference in ammonia affinity, specific growth rate, and substrate tolerance of nitrifiers in the SNCs. In addition, a conceptual model was developed to infer niche differentiation and possible interactions among the four types of nitrifiers. This study advances our understanding of niche differentiation and provides new strategies to further study their interactions among the four types of nitrifiers.