A membrane-associated MHC-I inhibitory axis for cancer immune evasion.

Immune-checkpoint blockade has revolutionized cancer treatment, but some cancers, such as acute myeloid leukemia (AML), do not respond or develop resistance. A potential mode of resistance is immune evasion of T cell immunity involving aberrant major histocompatibility complex class I (MHC-I) antigen presentation (AP). To map such mechanisms of resistance, we identified key MHC-I regulators using specific peptide-MHC-I-guided CRISPR-Cas9 screens in AML. The top-ranked negative regulators were surface protein sushi domain containing 6 (SUSD6), transmembrane protein 127 (TMEM127), and the E3 ubiquitin ligase WWP2. SUSD6 is abundantly expressed in AML and multiple solid cancers, and its ablation enhanced MHC-I AP and reduced tumor growth in a CD8+ T cell-dependent manner. Mechanistically, SUSD6 forms a trimolecular complex with TMEM127 and MHC-I, which recruits WWP2 for MHC-I ubiquitination and lysosomal degradation. Together with the SUSD6/TMEM127/WWP2 gene signature, which negatively correlates with cancer survival, our findings define a membrane-associated MHC-I inhibitory axis as a potential therapeutic target for both leukemia and solid cancers.

Stepwise activities of mSWI/SNF family chromatin remodeling complexes direct T cell activation and exhaustion.

Highly coordinated changes in gene expression underlie T cell activation and exhaustion. However, the mechanisms by which such programs are regulated and how these may be targeted for therapeutic benefit remain poorly understood. Here, we comprehensively profile the genomic occupancy of mSWI/SNF chromatin remodeling complexes throughout acute and chronic T cell stimulation, finding that stepwise changes in localization over transcription factor binding sites direct site-specific chromatin accessibility and gene activation leading to distinct phenotypes. Notably, perturbation of mSWI/SNF complexes using genetic and clinically relevant chemical strategies enhances the persistence of T cells with attenuated exhaustion hallmarks and increased memory features in vitro and in vivo. Finally, pharmacologic mSWI/SNF inhibition improves CAR-T expansion and results in improved anti-tumor control in vivo. These findings reveal the central role of mSWI/SNF complexes in the coordination of T cell activation and exhaustion and nominate small-molecule-based strategies for the improvement of current immunotherapy protocols.

SARS-CoV-2 exacerbates proinflammatory responses in myeloid cells through C-type lectin receptors and Tweety family member 2.

Despite mounting evidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) engagement with immune cells, most express little, if any, of the canonical receptor of SARS-CoV-2, angiotensin-converting enzyme 2 (ACE2). Here, using a myeloid cell receptor-focused ectopic expression screen, we identified several C-type lectins (DC-SIGN, L-SIGN, LSECtin, ASGR1, and CLEC10A) and Tweety family member 2 (TTYH2) as glycan-dependent binding partners of the SARS-CoV-2 spike. Except for TTYH2, these molecules primarily interacted with spike via regions outside of the receptor-binding domain. Single-cell RNA sequencing analysis of pulmonary cells from individuals with coronavirus disease 2019 (COVID-19) indicated predominant expression of these molecules on myeloid cells. Although these receptors do not support active replication of SARS-CoV-2, their engagement with the virus induced robust proinflammatory responses in myeloid cells that correlated with COVID-19 severity. We also generated a bispecific anti-spike nanobody that not only blocked ACE2-mediated infection but also the myeloid receptor-mediated proinflammatory responses. Our findings suggest that SARS-CoV-2-myeloid receptor interactions promote immune hyperactivation, which represents potential targets for COVID-19 therapy.

Targeting MHC-I inhibitory pathways for cancer immunotherapy.

The MHC-I antigen presentation (AP) pathway is key to shaping mammalian CD8+ T cell immunity, with its aberrant expression closely linked to low tumor immunogenicity and immunotherapy resistance. While significant attention has been given to genetic mutations and downregulation of positive regulators that are essential for MHC-I AP, there is a growing interest in understanding how tumors actively evade MHC-I expression and/or AP through the induction of MHC-I inhibitory pathways. This emerging field of study may offer more viable therapeutic targets for future cancer immunotherapy. Here, we explore potential mechanisms by which cancer cells evade MHC-I AP and function and propose therapeutic strategies that might target these MHC-I inhibitors to restore impaired T cell immunity within the tumor microenvironment (TME).

Key roles of autophagosome/endosome maturation mediated by Syntaxin17 in methamphetamine-induced neuronal damage in mice.

BACKGROUND: Autophagic defects are involved in Methamphetamine (Meth)-induced neurotoxicity. Syntaxin 17 (Stx17), a member of the SNARE protein family, participating in several stages of autophagy, including autophagosome-late endosome/lysosome fusion. However, the role of Stx17 and potential mechanisms in autophagic defects induced by Meth remain poorly understood. METHODS: To address the mechanism of Meth-induced cognitive impairment, the adenovirus (AV) and adeno-associated virus (AAV) were injected into the hippocampus for stereotaxis to overexpress Stx17 in vivo to examine the cognitive ability via morris water maze and novel object recognition. In molecular level, the synaptic injury and autophagic defects were evaluated. To address the Meth induced neuronal damage, the epidermal growth factor receptor (EGFR) degradation assay was performed to evaluate the degradability of the "cargos" mediated by Meth, and mechanistically, the maturation of the vesicles, including autophagosomes and endosomes, were validated by the Co-IP and the GTP-agarose affinity isolation assays. RESULTS: Overexpression of Stx17 in the hippocampus markedly rescued the Meth-induced cognitive impairment and synaptic loss. For endosomes, Meth exposure upregulated Rab5 expression and its guanine-nucleotide exchange factor (GEF) (immature endosome), with a commensurate decreased active form of Rab7 (Rab7-GTP) and impeded the binding of Rab7 to CCZ1 (mature endosome); for autophagosomes, Meth treatment elicited a dramatic reduction in the overlap between Stx17 and autophagosomes but increased the colocalization of ATG5 and autophagosomes (immature autophagosomes). After Stx17 overexpression, the Rab7-GTP levels in purified late endosomes were substantially increased in parallel with the elevated mature autophagosomes, facilitating cargo (Aß42, p-tau, and EGFR) degradation in the vesicles, which finally ameliorated Meth-induced synaptic loss and memory deficits in mice. CONCLUSION: Stx17 decrease mediated by Meth contributes to vesicle fusion defects which may ascribe to the immature autophagosomes and endosomes, leading to autophagic dysfunction and finalizes neuronal damage and cognitive impairments. Therefore, targeting Stx17 may be a novel therapeutic strategy for Meth-induced neuronal injury.

Global burden of diabetes mellitus from 1990 to 2019 attributable to dietary factors: An analysis of the Global Burden of Disease Study 2019.

AIMS: To analyse spatial and temporal changes in the global burden of diabetes mellitus (DM) attributable to dietary factors from 1990 to 2019. MATERIALS AND METHODS: The burden of DM was analysed in terms of age-standardized disability-adjusted life-year (DALY) rates and age-standardized death rates (ASDRs), which were obtained from the Global Burden of Disease Study 2019, and their corresponding estimated annual percentage changes (EAPCs). RESULTS: The ASDR exhibited a decreasing trend (EAPC = -0.02), while the age-standardized DALY rate exhibited an increasing trend (EAPC = 0.65). Forty-four percent of the burden of DM was attributable to dietary factors, with the three largest contributors being high intake of red meat, high intake of processed meat, and low intake of fruit. Residence in a region with a high sociodemographic index (SDI) was associated with a diet low in whole grains and high in red meat and processed meat, while residence in a low-SDI region was associated with a diet low in whole grains and fruits, and high in red meat. CONCLUSIONS: The age-standardized DALYs of DM attributable to dietary factors increased between 1990 and 2019 but differed among areas. The three largest dietary contributors to the burden of DM were high intake of red meat, high intake of processed meat, and low intake of fruit.

A glutaminase isoform switch drives therapeutic resistance and disease progression of prostate cancer.

Cellular metabolism in cancer is significantly altered to support the uncontrolled tumor growth. How metabolic alterations contribute to hormonal therapy resistance and disease progression in prostate cancer (PCa) remains poorly understood. Here we report a glutaminase isoform switch mechanism that mediates the initial therapeutic effect but eventual failure of hormonal therapy of PCa. Androgen deprivation therapy inhibits the expression of kidney-type glutaminase (KGA), a splicing isoform of glutaminase 1 (GLS1) up-regulated by androgen receptor (AR), to achieve therapeutic effect by suppressing glutaminolysis. Eventually the tumor cells switch to the expression of glutaminase C (GAC), an androgen-independent GLS1 isoform with more potent enzymatic activity, under the androgen-deprived condition. This switch leads to increased glutamine utilization, hyperproliferation, and aggressive behavior of tumor cells. Pharmacological inhibition or RNA interference of GAC shows better treatment effect for castration-resistant PCa than for hormone-sensitive PCa in vitro and in vivo. In summary, we have identified a metabolic function of AR action in PCa and discovered that the GLS1 isoform switch is one of the key mechanisms in therapeutic resistance and disease progression.

Both hormones and energy-rich compounds play a role in the mitigation of elevated pH on aluminum toxicity in Citrus sinensis leaves.

The contribution of plant hormones and energy-rich compounds and their metabolites (ECMs) in alleviating aluminum (Al) toxicity by elevated pH remains to be clarified. For the first time, a targeted metabolome was applied to identify Al-pH-interaction-responsive hormones and ECMs in Citrus sinensis leaves. More Al-toxicity-responsive hormones and ECMs were identified at pH 4.0 [4 (10) upregulated and 7 (17) downregulated hormones (ECMs)] than those at pH 3.0 [1 (9) upregulated and 4 (14) downregulated hormones (ECMs)], suggesting that the elevated pH improved the adaptation of hormones and ECMs to Al toxicity in leaves. The roles of hormones and ECMs in reducing leaf Al toxicity mediated by elevated pH might include the following aspects: (a) improved leaf growth by upregulating the levels of jasmonoyl-L-isoleucine (JA-ILE), 6-benzyladenosine (BAPR), N6-isopentenyladenosine (IPR), cis-zeatin-O-glucoside riboside (cZROG), and auxins (AUXs), preventing Al toxicity-induced reduction of gibberellin (GA) biosynthesis, and avoiding jasmonic acid (JA)-mediated defense; (b) enhanced biosynthesis and accumulation of tryptophan (TRP), as well as the resulting increase in biosynthesis of auxin, melatonin and secondary metabolites (SMs); (c) improved ability to maintain the homeostasis of ATP and other phosphorus (P)-containing ECMs; and (d) enhanced internal detoxification of Al due to increased organic acid (OA) and SM accumulation and elevated ability to detoxify reactive oxygen species (ROS) due to enhanced SM accumulation. To conclude, the current results corroborate the hypotheses that elevated pH reduces Al toxicity by upregulating the ability to maintain the homeostasis of ATP and other P-containing ECMs in leaves under Al toxicity and (b) hormones participate in the elevated pH-mediated alleviation of Al toxicity by positively regulating growth, the ability to detoxify ROS, and the internal detoxification of Al in leaves under Al toxicity. Our findings provide novel insights into the roles of hormones and ECMs in mitigating Al toxicity mediated by the elevated pH.

Protection of Oxygen Glucose Deprivation-Induced Human Brain Vascular Pericyte Injury: Beneficial Effects of Bellidifolin in Cellular Pyroptosis.

Pericytes play critical roles in the maintenance of brain vascular homeostasis. However, very little is currently known about how pericytes regulate ischemic stroke-induced brain injury. Inflammation is a key event in the pathobiology of stroke, in which the nod-like receptor protein-3 (NLRP3) inflammasome is involved in, triggering sterile inflammatory responses and pyroptosis. In the current study, an immortalized cell line derived from human brain vascular pericytes (HBVPs) was constructed, and it showed that HBVPs challenged with oxygen glucose deprivation (OGD) displays pronounced cellular excretion of LDH, IL-1ß, IL-18 and increased PI positive staining. Mechanistically, upon OGD treatment, NLRP3 forms an inflammasome with its adaptor protein apoptosis-associated speck-like protein, containing a caspase recruitment domain (ASC) and caspase-1, manifested as much more co-stainings of NLRP3, ASC and Caspase-1 in HBVPs, accompanied by the increased protein levels of NLRP3, ASC, caspase-1 as well as the pyroptosis-associated protein gasdermin D (GSDMD). Intriguingly, GSDMD-N shuttled to the mitochondrial membrane triggered by OGD exposure, which promoted massive mitochondria-derived ROS generation. Importantly, the invention value of the specific targets was evaluated by treatment with bellidifolin, a kind of ketone compound derived from Swertia chirayita in traditional Tibetan medicine. It showed that bellidifolin exerts beneficial effects and attenuates the formation of NLRP3/ASC/Caspase-1 complex, thereby impeding GSDMD-N shuttling and resultant ROS generation, protecting against OGD-induced HBVPs pyroptosis. Overall, these findings unravel the potential mechanisms of pericyte injury induced by OGD and indicate that bellidifolin may exert its beneficial effects on pyroptosis, thus providing new therapeutic insights into stroke.

Impact of connecting methods of continuous renal replacement therapy device on patients underwent extracorporeal membrane oxygenation: A retrospectively observational study.

OBJECTIVE: The objective of this study was to compare the safety and efficiency of different extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT) connection methods. BACKGROUND: The number of patients receiving ECMO is increasing, and the fields of application are getting wider. However, patients receiving ECMO are prone to acute kidney injury and fluid overload requiring CRRT. There are few comparative studies of two different systems of connecting CRRT device and ECMO from safety and efficacy perspective. METHODS: This retrospective observational study included patients receiving ECMO in the extracorporeal life support centre of the First Affiliated Hospital of Nanjing Medical University from June, 2015, to December, 2020. Patients were divided into the parallel system group and integrated system group according to the connecting method between ECMO circuit and CRRT line. The outcomes were discharge survival rate, CRRT therapeutic dose completion rate, CRRT catheterisation time, CRRT initiating time, local bleeding at the CRRT catheter site, mean filter life, ECMO circuit thrombosis, ECMO air leakage, or blood leakage due to CRRT. RESULTS: Thirty patients in the parallel system group and 70 patients in the integrated system group were finally included. The discharge survival rate and CRRT therapeutic dose completion rate were not significantly different between the two groups. The parallel system group had significant longer CRRT initiating time (49.0 ± 12.1 min vs. 14.6 ± 2.1 min, P < 0.001) and shorter filter life (11.5 ± 3.2 h vs. 47.3 ± 14.0 h, P < 0.001) than the integrated system group. The occurrence rate of local bleeding was 93.3% in the parallel system group, and there is no bleeding case in the integrated system group. There was no case of ECMO circuit thrombosis from CRRT as well as ECMO air or blood leakage caused by CRRT in either group. ECMO therapy can be adapted by adjusting the position of the CRRT outlet in the integrated system. CONCLUSIONS: Connecting CRRT and ECMO as an integrated system might accelerate CRRT initiation, avoid local bleeding, and prolong filter life compared to the parallel system. The chance of developing CRRT-related ECMO circuit leak and thrombosis is manageable.

CKAMP44 controls synaptic function and strength of relay neurons during early development of the dorsal lateral geniculate nucleus.

Relay neurons of the dorsal lateral geniculate nucleus (dLGN) receive inputs from retinal ganglion cells via retinogeniculate synapses. These connections undergo pruning in the first 2 weeks after eye opening. The remaining connections are strengthened several-fold by the insertion of AMPA receptors (AMPARs) into weak or silent synapses. In this study, we found that the AMPAR auxiliary subunit CKAMP44 is required for receptor insertion and function of retinogeniculate synapses during development. Genetic deletion of CKAMP44 resulted in decreased synaptic strength and a higher number of silent synapses in young (P9-11) mice. Recovery from desensitisation of AMPARs was faster in CKAMP44 knockout (CKAMP44-/- ) than in wild-type mice. Moreover, loss of CKAMP44 increased the probability of inducing plateau potentials, which are known to be important for eye-specific input segregation and retinogeniculate synapse maturation. The anatomy of relay neurons in the dLGN was changed in young CKAMP44-/- mice showing a transient increase in dendritic branching that normalised during later development (P26-33). Interestingly, input segregation in young CKAMP44-/- mice was not affected when compared to wild-type mice. These results demonstrate that CKAMP44 promotes maturation and modulates function of retinogeniculate synapses during early development of the visual system without affecting input segregation. KEY POINTS: Expression of CKAMP44 starts early during development of the dorsal lateral geniculate nucleus (dLGN) and remains stable in relay neurons and interneurons. Genetic deletion of CKAMP44 decreases synaptic strength and increases silent synapse number in dLGN relay neurons; increases the rate of recovery from desensitisation of AMPA receptors in dLGN relay neurons; and reduces synaptic short-term depression in retinogeniculate synapses. The probability of inducing plateau potentials is elevated in relay neurons of CKAMP44-/- mice. Eye-specific input segregation is unaffected in the dLGN of CKAMP44-/- mice. Deletion of CKAMP44 mildly affects dendritic arborisation of relay neurons in the dLGN.

Adaptive responses of carbon and nitrogen metabolisms to nitrogen-deficiency in Citrus sinensis seedlings.

BACKGROUND: In China, nitrogen (N)-deficiency often occurs in Citrus orchards, which is one of the main causes of yield loss and fruit quality decline. Little information is known about the adaptive responses of Citrus carbon (C) and N metabolisms to N-deficiency. Seedlings of 'Xuegan' (Citrus sinensis (L.) Osbeck) were supplied with nutrient solution at an N concentration of 0 (N-deficiency), 5, 10, 15 or 20 mM for 10 weeks. Thereafter, we examined the effects of N supply on the levels of C and N in roots, stems and leaves, and the levels of organic acids, nonstructural carbohydrates, NH4+-N, NO3--N, total soluble proteins, free amino acids (FAAs) and derivatives (FAADs), and the activities of key enzymes related to N assimilation and organic acid metabolism in roots and leaves. RESULTS: N-deficiency elevated sucrose export from leaves to roots, C and N distributions in roots and C/N ratio in roots, stems and leaves, thus enhancing root dry weight/shoot dry weight ratio and N use efficiency. N-deficient leaves displayed decreased accumulation of starch and total nonstructural carbohydrates (TNC) and increased sucrose/starch ratio as well as a partitioning trend of assimilated C toward to sucrose, but N-deficient roots displayed elevated accumulation of starch and TNC and reduced sucrose/starch ratio as well as a partitioning trend of assimilated C toward to starch. N-deficiency reduced the concentrations of most FAADs and the ratios of total FAADs (TFAADs)/N in leaves and roots. N-deficiency reduced the demand for C skeleton precursors for amino acid biosynthesis, thus lowering TFAADs/C ratio in leaves and roots. N-deficiency increased (decreased) the relative amounts of C-rich (N-rich) FAADs, thus increasing the molar ratio of C/N in TFAADs in leaves and roots. CONCLUSIONS: Our findings corroborated our hypothesis that C and N metabolisms displayed adaptive responses to N-deficiency in C. sinensis seedlings, and that some differences existed between roots and leaves in N-deficiency-induced alterations of and C and N metabolisms.

Molecular patterns of response and treatment failure after frontline venetoclax combinations in older patients with AML.

The BCL-2 inhibitor venetoclax combined with hypomethylating agents or low-dose cytarabine represents an important new therapy for older or unfit patients with acute myeloid leukemia (AML). We analyzed 81 patients receiving these venetoclax-based combinations to identify molecular correlates of durable remission, response followed by relapse (adaptive resistance), or refractory disease (primary resistance). High response rates and durable remissions were typically associated with NPM1 or IDH2 mutations, with prolonged molecular remissions prevalent for NPM1 mutations. Primary and adaptive resistance to venetoclax-based combinations was most commonly characterized by acquisition or enrichment of clones activating signaling pathways such as FLT3 or RAS or biallelically perturbing TP53. Single-cell studies highlighted the polyclonal nature of intratumoral resistance mechanisms in some cases. Among cases that were primary refractory, we identified heterogeneous and sometimes divergent interval changes in leukemic clones within a single cycle of therapy, highlighting the dynamic and rapid occurrence of therapeutic selection in AML. In functional studies, FLT3 internal tandem duplication gain or TP53 loss conferred cross-resistance to both venetoclax and cytotoxic-based therapies. Collectively, we highlight molecular determinants of outcome with clinical relevance to patients with AML receiving venetoclax-based combination therapies.

Methamphetamine-mediated dissemination of ß-amyloid: Disturbances in endocytosis, transport and clearance of ß-amyloid in microglial BV2 cells.

Methamphetamine (Meth) abuse can cause neurodegenerative-like changes, such as those observed in Alzheimer's disease (AD), characterized by extracellular amyloid-ß (Aß) deposition. The "spreading hypothesis" suggests that pathological Aß spreads over the entire brain, which depends on Aß endocytosis, transport and clearance. However, whether Meth exposure impacts these effects remains poorly understood. Microglia play an important role in the clearance of Aß. Therefore, the effects of microglia on Aß ingestion, degradation, and efflux under Meth challenge were investigated. Meth significantly engulfed and elicited a massive accumulation of Aß42 when extracellular administration of FAM-Aß42, accompanied by an increase in endocytosis-associated mRNA and protein expression, including TREM2 and VSP35. Meanwhile, FAM-Aß42 degradation was obviously retarded, since the colocalization of Aß42 and LDL, Aß42 and lysosomes was decreased, and syntaxin 17 might be involved in this process. Intriguingly, Meth dramatically facilitated FAM-Aß42 dissemination in microglia, characterized by the massive overlap between FAM-Aß42 and transferrin, which is destined to be excreted out of the cells. The facilitation of FAM-Aß42 spreading was further validated by the increased colocalization of FAM-Aß42 and CD63. Mechanistically, Meth mediated Aß42 spreading through the exosomal pathway, since an exosomal inhibitor remarkably hindered this process. Therefore, the current study elucidated a novel mechanism of Meth-induced accelerated progression in neurodegenerative disease, and targeting the inhibition of Aß1-42 efflux in microglia might provide beneficial effects for Meth-induced neural damage.

Associations between Physical Activity Trajectories and Incident Hypertension.

Purpose: We aimed to characterize physical activity (PA) trajectories across adulthood and to estimate their association with incident hypertension risk. Methods: Data were obtained from the China Health and Nutrition Survey (CHNS) conducted during 2004-2011. Group-based trajectory modeling (GBTM) was used to identify distinct groups of PA trajectories. The Cox proportional hazards model was used to investigate the association. Results: A total of 11,162 participants whose PA was repeatedly estimated by self-report from questionnaires two to four times in the CHNS were included in our study. During the 5.4 years of follow-up, 3824 incident hypertension cases were identified. Five distinct PA trajectories were identified in men: light and slight decline, light and gradual decline then sharp rise, light to medium-heavy then decline, medium-heavy and gradual decline, and heavy and sharp decline. Two distinct PA trajectories were identified in women: light and stable, and medium and gradual decline. The PA trajectory of medium-heavy and gradual decline was significantly associated with decreased risk of hypertension in men, with the hazard ratios and 95% confidence intervals (CI) being 0.80 (0.63, 0.99), 0.74 (0.59, 0.93), 0.76 (0.60, 0.96), and 0.70 (0.55, 0.88) in models 1-4, respectively. Conclusions: Our study identified five distinct long-term PA trajectories in men and two distinct trajectories in women. The PA trajectory of medium-heavy PA in early adulthood followed by gradual decline was found to be significantly associated with a decreased risk of hypertension in later life in men.

Exosomes derived from hypoxic bone marrow mesenchymal stem cells rescue OGD-induced injury in neural cells by suppressing NLRP3 inflammasome-mediated pyroptosis.

Exosomes have been shown to have therapeutic potential for cerebral ischemic diseases. In this study, we investigated the neuroprotective effects of normoxic and hypoxic bone marrow mesenchymal stromal cells-derived exosomes (N-BM-MSCs-Exo and H-BM-MSCs-Exo, respectively) on oxygen-glucose deprivation (OGD) injury in mouse neuroblastoma N2a cells and rat primary cortical neurons. The proportions of dead cells in N2a and primary cortical neurons after OGD injury were significantly increased, and N-BM-MSCs-Exo (40 µg/ml) could reduce the ratios, noteworthily, the protective effects of H-BM-MSCs-Exo (40 µg/ml) were more potent. Western blotting analysis indicated that N-BM-MSCs-Exo decreased the expression of NLRP3, ASC, Caspase-1, GSDMD-N, cleaved IL-1ß and IL-18 in N2a cells. However, H-BM-MSCs-Exo (40 µg/ml) was more powerful in inhibiting the expression of these proteins in comparison with N-BM-MSCs-Exo. Similar results were obtained in primary cortical neurons. Immunofluorescence assays showed that after N-BM-MSCs-Exo and H-BM-MSCs-Exo treatment, the co-localization of NLRP3, ASC, Caspase-1 and the GSDMD translocation from the nucleus to the cytoplasm and membrane after OGD injury were reduced in N2a cells and primary cortical neurons, and H-BM-MSCs-Exo had a more obvious effect. In addition, N-BM-MSCs-Exo and H-BM-MSCs-Exo significantly reduced lactate dehydrogenase (LDH) release and the IL-18 levels in cell culture medium in N2a cells and primary cortical neurons. Once again H-BM-MSCs-Exo induced these effects more potently than N-BM-MSCs-Exo. All of these results demonstrated that N-BM-MSCs-Exo and H-BM-MSCs-Exo have significant neuroprotective effects against NLRP3 inflammasome-mediated pyroptosis. H-BM-MSCs-Exo has a more pronounced protective effect than N-BM-MSCs-Exo and may be used to ameliorate the progression of cerebral ischemia and hypoxia injury in patients.

Boron-mediated amelioration of copper-toxicity in sweet orange [Citrus sinensis (L.) Osbeck cv. Xuegan] seedlings involved reduced damage to roots and improved nutrition and water status.

'Xuegan' (Citrus sinensis) seedlings were fertilized 6 times weekly for 24 weeks with 0.5 or 350 µM CuCl2 and 2.5, 10 or 25 µM H3BO3. Cu-toxicity increased Cu uptake per plant (UPP) and Cu concentrations in leaves, stems and roots, decreased water uptake and phosphorus, nitrogen, calcium, magnesium, potassium, sulfur, boron and iron UPP, and increased the ratios of magnesium, potassium, calcium and sulfur UPP to phosphorus UPP and the ratios of leaf magnesium, potassium and calcium concentrations to leaf phosphorus concentration. Many decaying and dead fibrous roots occurred in Cu-toxic seedlings. Cu-toxicity-induced alterations of these parameters and root damage decreased with the increase of boron supply. These results demonstrated that B supplementation lowered Cu uptake and its concentrations in leaves, stems and roots and subsequently alleviated Cu-toxicity-induced damage to root growth and function, thus improving plant nutrient (decreased Cu uptake and efficient maintenance of the other nutrient homeostasis and balance) and water status. Further analysis indicated that the improved nutrition and water status contributed to the boron-mediated amelioration of Cu-toxicity-induced inhibition of seedlings, decline of leaf pigments, large reduction of leaf CO2 assimilation and impairment of leaf photosynthetic electron transport chain revealed by greatly altered chlorophyll a fluorescence (OJIP) transients, reduced maximum quantum yield of primary photochemistry (Fv/Fm), quantum yield for electron transport (ETo/ABS) and total performance index (PIabs,total), and elevated dissipated energy per reaction center (DIo/RC). To conclude, our findings corroborate the hypothesis that B-mediated amelioration of Cu-toxicity involved reduced damage to roots and improved nutrient and water status. Principal component analysis showed that Cu-toxicity-induced changes of above physiological parameters generally decreased with the increase of B supply and that B supply-induced alterations of above physiological parameters was greater in 350 µM Cu-treated than in 0.5 µM Cu-treated seedlings. B and Cu had a significant interactive influence on C. sinensis seedlings.

Average mean arterial pressure in the first 6 hours of extracorporeal cardiopulmonary resuscitation in the prediction of the prognosis of neurological outcome: a single-center retrospective study.

OBJECTIVE: To study the correlation between the mean arterial pressure (MAP) level in the first 6 hours of extracorporeal cardiopulmonary resuscitation (ECPR) and patients' neurological outcomes. METHODS: Sex, age, basic comorbidities, the time from the first cardiac arrest to the start of CPR, the time from the first cardiac arrest to extracorporeal membrane oxygenation (ECMO), standardized ECMO flow, and the pH value at the beginning of ECMO and after 6 hours were recorded. MAP was recorded every 2 hours during the first 6 hours, and the average was calculated. The lactic acid clearance rate of the first 6 hours was calculated. Evaluated the neurological prognosis of patients at discharge. Then the patients were divided into groups according to their average MAP, and the above variables were compared in groups. RESULTS: Enrolled 63 adult ECPR patients. There were no statistically significant differences in sex, age, basic comorbidities, the time from the first cardiac arrest to the start of conventional CPR, the time from the first cardiac arrest to the start of ECMO, standardized ECMO flow, 6-hour lactic acid clearance rate, pH value at the sixth hour of operation between two groups. The pH value at the start of ECMO, survival rate, and good prognosis rate in low average MAP group were significantly lower. Low average MAP was associated with poor neurological outcomes (relative risk (RR) 1.50, 95% CI 1.17, 1.92). The RR of good neurological outcome for patients with average MAP ⩾65 mmHg was 5.91 (95% CI 1.45, 24.06), and the RR for average MAP ⩾100 mmHg was 1.18 (95% CI 0.19, 7.52). CONCLUSION: For ECPR patients, average MAP <65 mmHg in the first 6 hours of ECPR indicates a poor neurological prognosis. However, whether higher average MAP levels can improve the neurological prognosis of ECPR patient remains to be further studied.

High pH Alleviated Sweet Orange (Citrus sinensis) Copper Toxicity by Enhancing the Capacity to Maintain a Balance between Formation and Removal of Reactive Oxygen Species and Methylglyoxal in Leaves and Roots.

The contribution of reactive oxygen species (ROS) and methylglyoxal (MG) formation and removal in high-pH-mediated alleviation of plant copper (Cu)-toxicity remains to be elucidated. Seedlings of sweet orange (Citrus sinensis) were treated with 0.5 (non-Cu-toxicity) or 300 (Cu-toxicity) µM CuCl2 × pH 4.8, 4.0, or 3.0 for 17 weeks. Thereafter, superoxide anion production rate; H2O2 production rate; the concentrations of MG, malondialdehyde (MDA), and antioxidant metabolites (reduced glutathione, ascorbate, phytochelatins, metallothioneins, total non-protein thiols); and the activities of enzymes (antioxidant enzymes, glyoxalases, and sulfur metabolism-related enzymes) in leaves and roots were determined. High pH mitigated oxidative damage in Cu-toxic leaves and roots, thereby conferring sweet orange Cu tolerance. The alleviation of oxidative damage involved enhanced ability to maintain the balance between ROS and MG formation and removal through the downregulation of ROS and MG formation and the coordinated actions of ROS and MG detoxification systems. Low pH (pH 3.0) impaired the balance between ROS and MG formation and removal, thereby causing oxidative damage in Cu-toxic leaves and roots but not in non-Cu-toxic ones. Cu toxicity and low pH had obvious synergistic impacts on ROS and MG generation and removal in leaves and roots. Additionally, 21 (4) parameters in leaves were positively (negatively) related to the corresponding root parameters, implying that there were some similarities and differences in the responses of ROS and MG metabolisms to Cu-pH interactions between leaves and roots.

Extracellular Vesicle-Mediated Delivery of Circular RNA SCMH1 Promotes Functional Recovery in Rodent and Nonhuman Primate Ischemic Stroke Models.

BACKGROUND: Stroke is a leading cause of adult disability that can severely compromise the quality of life of patients, yet no effective medication currently exists to accelerate rehabilitation. A variety of circular RNA (circRNA) molecules are known to function in ischemic brain injury. Lentivirus-based expression systems have been widely used in basic studies of circRNAs, but safety issues with such delivery systems have limited exploration of the potential therapeutic roles for circRNAs. METHODS: Circular RNA SCMH1 (circSCMH1) was screened from the plasma of patients with acute ischemic stroke by using circRNA microarrays. Engineered rabies virus glycoprotein-circSCMH1-extracellular vesicles were generated to selectively deliver circSCMH1 to the brain. Nissl staining was used to examine infarct size. Behavioral tasks were performed to evaluate motor functions in both rodent and nonhuman primate ischemic stroke models. Golgi staining and immunostaining were used to examine neuroplasticity and glial activation. Proteomic assays and RNA-sequencing data combined with transcriptional profiling were used to identify downstream targets of circSCMH1. RESULTS: CircSCMH1 levels were significantly decreased in the plasma of patients with acute ischemic stroke, offering significant power in predicting stroke outcomes. The decreased levels of circSCMH1 were further confirmed in the plasma and peri-infarct cortex of photothrombotic stroke mice. Beyond demonstrating proof-of-concept for an RNA drug delivery technology, we observed that circSCMH1 treatment improved functional recovery after stroke in both mice and monkeys, and we discovered that circSCMH1 enhanced the neuronal plasticity and inhibited glial activation and peripheral immune cell infiltration. CircSCMH1 binds mechanistically to the transcription factor MeCP2 (methyl-CpG binding protein 2), thereby releasing repression of MeCP2 target gene transcription. CONCLUSIONS: Rabies virus glycoprotein-circSCMH1-extracellular vesicles afford protection by promoting functional recovery in the rodent and the nonhuman primate ischemic stroke models. Our study presents a potentially widely applicable nucleotide drug delivery technology and demonstrates the basic mechanism of how circRNAs can be therapeutically exploited to improve poststroke outcomes.